Modelling engine wear and WEP limitations

[Kurfürst]

Some thoughts carried over from this thread:
http://forum.1cpublishing.eu/showthread.php?t=21632&page=6

Modelling max. output limitations perhaps could be solved with a 'soft limit' programming. For example you could fly with max throttle as long as you'd want (until the engine temperature limits are observed). But you'd carry over wear on the engine, and at an accelerated rate.

For example, an engine have a practical TBO of 100 hours in real life. After that its starts to loose power, and there's an increasing chance for failure of some part. "Wear Units" would be deducted from it.

Each power rating you use would have an associated Wear multiplier. Say 1x for what is described as continous use in the engine manual, 5x for what is desribed as normal maximum power for the engine, like 6.25 lbs or 1.35ata for the RRM/601, and 10x for what was considered overload, like +12/1.45ata. Special penelties can be imposed for firewalling the engine while still cold or shutting it off while still too hot.

This could be tracked for all aircraft individually (if map has a limited number of aircraft). So, you may get very unluckly if you get to fly, after bailing out from your previous crate, say Bf 109E-3 No. 13 that was previously used by someone on the server very unkind to the engine, it might fail on you on takeoff.

Alternatively, such planes that were worn off by planes could be taken away after landing by the server, until their engine is "overhauled". So it means loss of available planes for an hour.

There could be also a generic multiplier setting, or WEAR MODIFIER, which could be set by the admin of the server. This would keep the wear on normal levels, or speed it up to enforce the rules.

So for a practical example. You take off in a figher with a fresh engine. It has 100 hours of "hit points" before it needs to be overhauled and the plane will be missing for 2 hours of server time before usable again for one side.

You take off at maximum power (1 minutes, counts as 10 minutes because of 10x multipliers), climb at normal WEP for 5 minutes to gain altitude (5minx5 = 25), cruise for 10 minutes (10x1), and then find a jerry, furball with him at +12 for 5 minutes (5minx10=50 mins) and leave, cruise back to base (+10), and land. You are impatient and shut off the engine immidiately, not leaving it time cool (+60 penalty).

Alltogether you have used up quite a bit of TBO time:

10 mins worth on a hastened take off
25 mins worth on climb
20 minutes on cruise
50 minutes for combat
60 minutes for not following engine operating instructions

Alltogether 165 mins, or almost 3 hours of TBO. You have actually flown 31 minutes.

Now, the server admin might choose to be funny, and use x10 WEAR MODIFIER, meaning that engines get used up 10 times as fast. Meaning that on your 4th similiar sortie, something funny is quite likely to happen to your engine.

Thoughts?

[Viper2000]

I like this idea.

IRL you only need one engine failure at the wrong time to kill you. This is quite a powerful argument for conservatism. In the sim, we've got a refly button and therefore are likely to fly rather differently even if the other aspects of the model are perfect.

Basically you'd have from sunset to sunrise to get a squadron of day fighters maintained, and in the height of summer you'd need a lot of manpower to put in the man-hours per flying-hour required in the short window of darkness available. If you'd didn't get the job done then you wouldn't be able to scramble a full squadron.

It's very unlikely that corners would be cut until the airforce in question was really falling apart, because it's better to lose a sortie than to lose an aeroplane & pilot.

Therefore, the real driver behind the increased risk of failure associated with pushing airframes and engines hard would be that life consumption might exceed that assumed in the maintenance schedule.

However, in the wider scheme of things, the maintenance schedule was a constantly moving target, adjusted in the light of operational experience. If the accident rate went up, the maintenance intervals for suspect components would be reduced.

So, unlucky pilots would be unlucky, but at a force level the real impact would be upon the sortie generation rate achievable with the available manpower, which would vary gradually, over a timescale of months rather than days.

I therefore think that the only way to encourage reasonable flying with a fully realistic model outside of a long-term campaign environment is to dock points for rough treatment of airframe and engine, because otherwise you'd end up having to deliberately make the models unrealistic in some way.

Having said that, if you're going to tweak the model for gameplay-friendly wear/failure behaviour, then a wear modifier as suggested above is a good way of doing it, especially if it's connected to the external weathering model. Pilots could then select their individual airframe in the armament screen rather than just the type and loadout, which would add extra depth to the simulation.

Pilots scoring lots of kills could get extra maintenance (and possibly the addition of an ashtray and telescopic sight to their 109's cockpit model if they're extremely successful ;) )

[Seadog]

Flight testing at 12lb boost:

http://www.wwiiaircraftperformance.org/hurricane/hurricane-12lbs-14nov39.jpg

[Seadog]

Some thoughts carried over from this thread:
http://forum.1cpublishing.eu/showthread.php?t=21632&page=6

Modelling max. output limitations perhaps could be solved with a 'soft limit' programming. For example you could fly with max throttle as long as you'd want (until the engine temperature limits are observed). But you'd carry over wear on the engine, and at an accelerated rate.






Using overboost doesn't really put much wear on the engine (at least on the Merlin), however, running it with gauges into the "red" does, so track the time that the engine is run in the "red" and engine failure probability should increase disproportionately over time for abused engines.

[Liz Lemon]

Have you looked at how this game is modelling engine? Physical wear is already there.

[Kurfürst]

Have you looked at how this game is modelling engine? Physical wear is already there.

I am aware it was promised. I speak of multiplayer, where some may be concerned about players running WEP all the time.

[Skoshi Tiger]

Janes USNF had a similar arrangement for campaigns. Where the carrier had it complement of aircraft. After a mission each aircraft was presented with a list of damage/work that needed done.

You had limited maintenance resources that you had to allocate to fix up the problems. Sometimes you had to take out the less capable aircraft so that the good ones could be used in more important missions later.

Every so often new aircraft were brought added.

Ordinance also had to be managed in case you ran out special purpose weapons like LGB for pin point targets.

Now with the scripting language used in the COD mission builder I wonder if you can write information to a file, so that it can be read for subsequent missions?

Cheers

[Crumpp]

Using overboost doesn't really put much wear on the engine

It certainly does Seadog.

Ask any mechanic, if you want to save the engine, pull the throttle back......

;)

[Seadog]

It certainly does Seadog.

Ask any mechanic, if you want to save the engine, pull the throttle back......

;)

see:
http://forum.1cpublishing.eu/showpost.php?p=294693&postcount=71

During the BofB RAFFC lost about 1000 Hurricanes and Spitfires from 10 July to 30 October 1940. The average fighter didn't last long enough for engine wear to become a major factor, even if 12lb boost caused major wear, and it didn't. These aircraft were expended at a furious pace and engine wear due to 12lb boost was a very minor issue in the grand scheme of things and I would suspect, that statistically speaking, pilots who "pulled the plug" were more likely to bring their aircraft home than ones who didn't simply because "pulling the plug" denotes situational awareness and the average pilot shot down, never sees his attacker.

[Crumpp]

engine wear

What you don't seem to understand is that engine is overloaded just as FC says. That means it can fail.

If it does not fail the first time, it's life is dramatically shortened in comparison to just running the engine at its rated maximum continuous power of +7lbs.

That is why FC dictates the engine is dead-lined, the use of +12lbs entered into the maintenance logs, and the engine must be inspected by a mechanic before it can be returned to service.

If your engine fails in an airplane, their is no re-fly button. It is the pilot life on the line and he only has ONE.

In accidents resulting from engine failure in flight, if the pilot deviated from published operating standards for the engine, it is a factor in the engine failure in EIGHTY FIVE PERCENT of the engine failures recorded by the FAA.

Let that sink in for a moment.

[Seadog]

What you don't seem to understand is that engine is overloaded just as FC says. That means it can fail.

If it does not fail the first time, it's life is dramatically shortened in comparison to just running the engine at its rated maximum continuous power of +7lbs.

That is why FC dictates the engine is dead-lined, the use of +12lbs entered into the maintenance logs, and the engine must be inspected by a mechanic before it can be returned to service.

If your engine fails in an airplane, their is no re-fly button. It is the pilot life on the line and he only has ONE.

In accidents resulting from engine failure in flight, if the pilot deviated from published operating standards for the engine, it is a factor in the engine failure in EIGHTY FIVE PERCENT of the engine failures recorded by the FAA.

Let that sink in for a moment.
http://www.wwiiaircraftperformance.org/hurricane/hurricane-12lbs-14nov39.jpg
The trials here:

state:
This test was terminated at 49.5 hours (8.5 hours at 12lb boost) by a cylinder head glycol leak in one cylinder, the joint being of an early unshrouded type which has given similar trouble under normal flying conditions.

So the failure was of a gasket which was known to be prone to failure for reasons unrelated to 12lb/3000rpm operation, but as is reported; "...the life of the Merlin engines under the emergency 12lbs boost conditions should be very little reduced from the normal..."

Dowding states:

6. It is in the interests of pilots themselves, when operations with the enemy may have resulted in engine limitations being exceeded, to acquaint the maintenance personnel with the facts, so that oil filters may be inspected [B]at the first convenient opportunity to investigate whether damage to the bearings has result. so this is not anything like a requirement for an enforced engine check after using 12lb/3000rpm for more than 5 mins.

The Merlin in Perspective, p.39, states that, at 3000 rpm, a bearing could run with the oil cut off for 15 seconds before the temp started to rise. Bearing failures in the early Merlins (p.36)were most likely to be caused by excessive rpm (3600rpm+) during prolonged dives at reduced power leading to oil starvation and due to improper design features which were corrected in later versions. 12lb/3000rpm operation was not a factor.

Engine failures in flight are almost always due to fuel starvation due to improper engine management.

It would be nice if you could provide some sources.

[Crumpp]

so this is not anything like a requirement for an enforced engine check after using 12lb/3000rpm for more than 5 mins.

Sure there is...

It is clearly stated in the instructions.

Certainly the Technical Order is not so dismissive of the engines limitations or the modifications required as the Fighter Command appeal to higher for approval of the rating.

http://img861.imageshack.us/img861/5967/12lbmaintenancerequirem.png (http://imageshack.us/photo/my-images/861/12lbmaintenancerequirem.png/)

Reminds me of the whole 100/150 grade clownery. The Technical Branch says, it will hurt the engines while the operational side says we want the performance and we want it now.

It lasted some 2 or 3 months in actual operational use in the 2nd TAF before maintenance issues forced the withdrawal completely. ;)

Performance without reliability is no gain at all in aviation.

[Crumpp]

It would be nice if you could provide some sources.

Sure, try the FAA or the NTSB. Both produce some good statistical reports every year.

http://img853.imageshack.us/img853/6412/accidents.jpg (http://imageshack.us/photo/my-images/853/accidents.jpg/)

http://img828.imageshack.us/img828/4715/accidents2.jpg (http://imageshack.us/photo/my-images/828/accidents2.jpg/)

[Seadog]

Sure, try the FAA or the NTSB. Both produce some good statistical reports every year.



Aircraft powerplant almost always relates to engine failure due to improper fuel management or things like premature engine brake deployment, failure to observe proper cooling/heating requirements etc...I suspect that failure due to prolonged running at high supercharger boost is pretty low on the list...:rolleyes:

[Seadog]

Sure there is...


Reminds me of the whole 100/150 grade clownery. The Technical Branch says, it will hurt the engines while the operational side says we want the performance and we want it now.

It lasted some 2 or 3 months in actual operational use in the 2nd TAF before maintenance issues forced the withdrawal completely. ;)


See:
http://forum.1cpublishing.eu/showpost.php?p=294770&postcount=73

it does not require grounding of the aircraft pending an engine inspection merely an assessment as whether or not an inspection is needed, which is exactly as the underlined portion of the memo states. Again, it almost seems that you are having a hard time translating english language documents.
Regarding the 150 grade fuel issue, this is discussed here:
http://www.wwiiaircraftperformance.org/150grade/150-grade-fuel.html
in detail but this is not relevant here, and it is suffice to say that the use of 150 grade fuel continued until war's end.

[Seadog]

.

In accidents resulting from engine failure in flight, if the pilot deviated from published operating standards for the engine, it is a factor in the engine failure in EIGHTY FIVE PERCENT of the engine failures recorded by the FAA.

.

Most people reading this thread would have assume that you were referring to the Fleet Air Arm, which was a operator of Merlin engines.

Of course it turns out that you are referring to the USA's Federal Aviation Agency...:roll: and trying to roll out civil aviation accident stats to support some kind of argument regarding the Battle of Britain and the use of supercharged engines in combat...!!!!

Simply unbelievable...:!:

Maybe you have this confused with a MFS forum?

[TomcatViP]

At least I had a good laugh :grin: Thx !

Perhaps you can understand now why a isolated pilot (not so) in the middle of the channel will only reluctantly use his emergency boost and why he wld be pleased to read in the plane log if the guy right before him has alrdy burnt the engine.

By the way the IL2's 109 had a good eng damage model. Some adaptation wld seem necessary (like a random time length and an initial cte tracing the past use of boost by the player). Just my 2 cents...

[Crumpp]

Most people reading this thread would have assume that you were referring to the Fleet Air Arm

You do understand that physics dictates the margins of safety for flight? A 1.5 Margin is the industry standard for anything that flies....

It does not matter whether you are Military or Civilian, you get off the ground under the same physical laws and restraints.

It does not require grounding of the aircraft pending an engine inspection merely an assessment as whether or not an inspection is needed

The language is clear. A logbook entry in the maintenance logs followed by an inspection is required.

To translate that to non-pilots and A&P's....that means the aircraft is automatically grounded until a mechanic inspects the engine and returns it service.

[Crumpp]

Perhaps you can understand now why a isolated pilot (not so) in the middle of the channel will only reluctantly use his emergency boost and why he wld be pleased to read in the plane log if the guy right before him has alrdy burnt the engine.

LOL, because he enjoys living!!

Here is my return trip this past weekend. ATC vectored me around that development off my right wing in the picture.

Very Heavy precip with 1/2 inch hail....

http://img801.imageshack.us/img801/80/thunderstormx.jpg (http://imageshack.us/photo/my-images/801/thunderstormx.jpg/)

http://img36.imageshack.us/img36/5491/thunderstorm2.jpg (http://imageshack.us/photo/my-images/36/thunderstorm2.jpg/)

http://img855.imageshack.us/img855/1866/thunderstorm4.jpg (http://imageshack.us/photo/my-images/855/thunderstorm4.jpg/)

[Seadog]

The language is clear. A logbook entry in the maintenance logs followed by an inspection is required.

To translate that to non-pilots and A&P's....that means the aircraft is automatically grounded until a mechanic inspects the engine and returns it service.


The "language" does not state that and the pilot's notes for the Merlin III state:
http://www.spitfireperformance.com/spit1pn-12lbs.jpg

and this requires a pilot to log and report the use of combat power.

Dowding's memo states:

"
5. The consequences of exceeding the engine limitations are liable to manifest themselves on some subsequent occasion, perhaps during night flying or over the sea out or gliding distance from land. Pilots therefore, are to be instructed not to exceed;
(i) Maximum specified temperatures for oil and engine coolant.

(ii) Limit of 5 mins. for maximum of 3000 r.p.m. at 6.25 lbs/sq.in. or more.

6. It is in the interests of pilots themselves, when operations With the enemy may have resulted in engine limitations being exceeded, to acquaint the maintenance personnel with the facts, so that oil filters may be inspected at the first convenient opportunity to investigate whether damage to the bearings has resulted."

"...first convenient opportunity..." during wartime is hardly grounded until inspected.

and:
http://www.wwiiaircraftperformance.org/ap1590b.jpg
states

"11. The use, in an emergency, of this high boost pressure is a definite overload condition on Merlin engine and therefore all occasions on which it is essential to make use of the + 12 lb must be reported by the pilot and recorded in the engine log book so that the engineer officer may be able to assess the reduction in life between overhauls and the need for special inspections. "

"...recorded in the engine log book so that the engineer officer may be able to assess the reduction..." leaves it to the discretion of the engineer officer to decide whether an inspection is needed. In no way does this call for mandatory inspections.

and none of these calls for grounding the aircraft until an inspection is made. Rather these call for assessments and inspections as needed depending on the entries in the log books and thus presumably the duration and circumstances under which 12lb/3000rpm was used. Dowding's memo specifically states that operation at 12lb/3000rpm for 5 minutes or less does not need to be reported to maintenance personnel.

Again, the average life of a BofB RAFFC fighter was less than 2 months, so no one was unduly concerned about the use of 12lb/3000rpm in combat situations since the average fighter never survived long enough for engine life to be a major issue. Since about 1000 fighters were lost and something like 60,000 sorties were flown during the battle, the average RAFFC fighter probably had less than 100 hours on the clock when lost. Dowding's memo, for example, does not mention admin penalties for exceeding 5mins at 12lb/3000 rpm but merely states that they not do so, and to report the time when they do.

[Seadog]

LOL, because he enjoys living!!



Right, so if you are being chased a swarm of Me109s, you'll let yourself be shot down rather than exceed 12lb/3000rpm for more than 5mins?

What you don't seem to be considering is that a Spitfire for example has 85 gals of fuel. TO, climb and cruise to say mid channel will consume say on average about 25 gals, and return will also require 20 gals so the max fuel allowance for combat will be about 40 gals and thus about 25mins, max, at 12lb/3000rpm. No one is going to be using 12lb/3000rpm for more than a few minutes unless there is simply no other way to stay alive, because the fuel capacity of these aircraft is severely limited.

[ICDP]

Right, so if you are being chased a swarm of Me109s, you'll let yourself be shot down rather than exceed 12lb/3000rpm for more than 5mins?

What you don't seem to be considering is that a Spitfire for example has 85 gals of fuel. TO, climb and cruise to say mid channel will consume say on average about 25 gals, and return will also require 20 gals so the max fuel allowance for combat will be about 40 gals and thus about 25mins, max, at 12lb/3000rpm. No one is going to be using 12lb/3000rpm for more than a few minutes unless there is simply no other way to stay alive, because the fuel capacity of these aircraft is severely limited.

EXACTLY

Most pilots would engage overboost during an emergency only. Once the danger was gone you would imediatley ease of on the power, because the next thing on your mind would be, lets not blow the engine... it's the only one I've got. Frankly, constantly saying +12lbs boost could be used without fear until the fuel ran out is ludicrous. The pilot manual and RAF memos explicity state that +12lbs boost was to be used in emergencies only and only for 5 minutes at a time. Do you think they set these limits for fun.

[Crumpp]

The "language" does not state that and the pilot's notes for the Merlin III state:

Sure it does! States right there he must make a log book entry and have the aircraft inspected.

http://img641.imageshack.us/img641/7338/inspectionafterboost.jpg (http://imageshack.us/photo/my-images/641/inspectionafterboost.jpg/)

What do you think is going to happen when he makes that log book entry and reports it to maintenance? They must comply with their orders and conduct an inspection, too.

You think the pilot overrides the mechanic on whether or not the airplane is ready to fly?

No, the airplane is grounded until the mechanic conducts the inspection.

[Crumpp]

Most pilots would engage overboost during an emergency only. Once the danger was gone you would imediatley ease of on the power, because the next thing on your mind would be, lets not blow the engine... it's the only one I've got.

Exactly. It is no different than the Take Off rating in a Lycoming O-360. As soon as the trees are cleared, it is time to back off. Otherwise you risk having the engine fail as it is not designed to maintain 28mmHg @ 2700 rpm.

Hartzell HC-C2YK-1BF/F7666A-2 Propeller on 180 Hp Lycoming engines equipped with Electronic Ignition or FADEC

http://www.vansaircraft.com/pdf/Hartzell_c2yk.pdf

It is much better to be down on the ground wishing you were flying than flying and wishing you were down on the ground.

It amazing that most gamers just think changing a few parts is no big deal. They don't seem to understand the low safety margins required for flight. Facts are it is the simple things that can kill you in aviation because of those low margins.

Any modification to the standard engine configuration to include high compression pistons, electronic ignition, FADEC, tuned induction and exhaust, and turbocharging or turbonormalizing have the potential to adversely effect the propeller vibration characteristics and stress amplitudes.

[Seadog]

Sure it does! States right there he must make a log book entry and have the aircraft inspected.

http://img641.imageshack.us/img641/7338/inspectionafterboost.jpg (http://imageshack.us/photo/my-images/641/inspectionafterboost.jpg/)

What do you think is going to happen when he makes that log book entry and reports it to maintenance? They must comply with their orders and conduct an inspection, too.

You think the pilot overrides the mechanic on whether or not the airplane is ready to fly?

No, the airplane is grounded until the mechanic conducts the inspection.

It does not state: "and have the aircraft inspected."

It does not call for an inspection. It requires a report and log entry and then the engineer officer decides whether an inspection is needed. Dowding's memo states that an inspection will be done "when convenient" only after more than than 5 mins at 12lb.

http://forum.1cpublishing.eu/showpost.php?p=294815&postcount=20

If you really are a pilot, then I think you should show a bit more maturity and stop making things up and realize that wartime combat is not the same as peacetime civil aviation.

What do you think is going to happen when he makes that log book entry and reports it to maintenance? They must comply with their orders and conduct an inspection, too.

Show us an order where an inspection is mandatory and not discretionary.

[Seadog]

EXACTLY

Most pilots would engage overboost during an emergency only. Once the danger was gone you would imediatley ease of on the power, because the next thing on your mind would be, lets not blow the engine... it's the only one I've got. Frankly, constantly saying +12lbs boost could be used without fear until the fuel ran out is ludicrous. The pilot manual and RAF memos explicity state that +12lbs boost was to be used in emergencies only and only for 5 minutes at a time. Do you think they set these limits for fun.

When you have an aircraft with 85 or gallons of fuel, fuel consumption is never far from your mind, and this will provide the disincentive to not use 12lb boost without justification. However, in fighting over Britain it will be the Luftwaffe pilot who will most fear "to pull the plug" and the tactical advantage to an RAFFC pilot is obvious.

Yet, the trials of, and the operational experience of Merlin engine was that it would run continuously at 12lb/3000rpm with little fear of failure as long as it was running with adequate cooling and lubrication.

[Crumpp]

It does not state: "and have the aircraft inspected."

YES it does Seadog. It is the two different sets of instructions.

First the pilot logs the event of using Emergency Power. THEN the mechanic must inspect the motor and return it service.

http://img847.imageshack.us/img847/5967/12lbmaintenancerequirem.png (http://imageshack.us/photo/my-images/847/12lbmaintenancerequirem.png/)

The pilot MUST report the use and engine MUST be inspected. It is cut and dry.

http://img851.imageshack.us/img851/7338/inspectionafterboost.jpg (http://imageshack.us/photo/my-images/851/inspectionafterboost.jpg/)

What do think the mechanics are going to do when the pilot reports using +12lbs Emergency rating??

"Top, Top, Cheerio Ol'Boy....Off you go and fight the dirty Hun in that plane whose engine might fail while we disobey our orders??"

Of course not, they will comply with their orders and Technical Bulletins to inspect the engine which is the second part. The plane will be placed out of service pending their inspection as it's reliability is now suspect.

I would think the inspection at minimum would consist of the 100 hour inspection procedures. Change the oil, oil analysis, filter changes, compression check, and over all inspection for cracks/leaks/function would be in order to ensure engine health.

That is about 3 hours worth of work on a Merlin engine. If they check crank bearing tolerances then you can add about an hour to it. If they find something then of course, it will get fixed or replaced.

Once that is done, the mechanic would enter into the logbook the work performed and return the aircraft to service. A few hours in the shop is certainly worth the pilots peace of mind.

Your claim of it being able to run continuously on +12lbs is plain ridiculous.

Show us an order where an inspection is mandatory and not discretionary.

Read the documents you posted....

"All Occasions" and "must be reported" is not discretionary. It is mandatory.

[Viper2000]

Exactly. It is no different than the Take Off rating in a Lycoming O-360. As soon as the trees are cleared, it is time to back off. Otherwise you risk having the engine fail as it is not designed to maintain 28mmHg @ 2700 rpm.

It's the prop that might fail, not the engine. This is arguably worse because losing a blade will cause huge amounts of vibration, which will make it very difficult to fly the aeroplane (because you won't be able to see very well) and may cause secondary failures if the engine isn't rapidly shut down. If the engine is shaken out of its mounting then the CoG will probably shift so far that the aeroplane will be uncontrollable, and unless you're wearing a parachute and are able to use it, that's almost certainly going to result in a fatal accident. Whereas just having the engine fail means a forced landing, which one would hope to have a good chance of walking away from.

28 mm Hg is a pretty severe vacuum... I suspect that you mean 28" Hg, which would be almost atmospheric pressure, roughly what you'd expect for a naturally aspirated engine running WOT at sea level on a standard day.

Actually, you'll find that because something like an O-360 is naturally aspirated, it's more likely to tolerate WOT operation than a supercharged or turbocharged engine because the manifold pressure (and therefore the power) simply lapses away as you climb. (Of course, a lot of GA aeroplanes don't climb very well, so YMMV, especially if you subscribe to the old-fashioned view that takeoff = 1 minute unless something has gone wrong.)

Equally, you risk engine failure at all times. Even before you start the engine (which is why you should treat all props as live, because magnetos can fail ON).

You should never fly an aeroplane into a situation in which losing an engine will leave you with no options, because as Chuck Yeager wisely advises:

Always leave yourself a way out.

So I would modify your first statement to say that "Otherwise you increase risk having the engine fail beyond that assumed during certification".

This increase might well be pretty small, especially if the engine has a long overhaul life and you only misbehave very infrequently. Indeed, if you're prepared get the engine overhauled more frequently than the nominal TBO then you may actually be able to charge about the sky WOT all the time and still have a very safe engine.

Does this mean that you can ignore the limits? Of course not.

But it's important to understand what the limits are about. They're intended to deliver acceptably high reliability at the end of the certified overhaul life of the average engine, based upon a set of usage assumptions.

This means that the same engine might have very different ratings for different applications. For example, given the same total number of flying hours, if you were going to fly lots of short sorties, you'd spend a higher proportion of each flying hour at takeoff power than if you were going to fly a smaller number of longer sorties. You'd therefore feel comfortable in allowing a more aggressive takeoff rating in the latter case than in the former.

If you've got a short duration manifold pressure limit, a naturally aspirated engine, and a reasonably good power:weight ratio, you may well find that you can actually operate the aeroplane WOT from takeoff to top of descent, without exceeding the limits, because the aeroplane climbs fast enough that the manifold pressure has lapsed to less than or equal to the maximum continuous rating before the time limit is exceeded.

Something like a GTSIO-520 might be a bit less forgiving, but if you look at the TCDS (http://rgl.faa.gov/regulatory_and_guidance_Library/rgMakeModel.nsf/0/00095e3c8b8baa7f8525670e0047a815/$FILE/E7ce.pdf), you'll find that the manufacturer helpfully just flatrated it such that the takeoff power = max continuous.

Engineers do this because it is generally assumed that pilots can't be trusted to obey the limits in the Pilot's Notes. Sad but true.

Now, actually AFAIK these engines didn't have the best reliability record in the world, but that was more due to how people operated them in the cruise than due to people charging around with all the levers rammed into the firewall.

If you go to the average flying school in the UK, at least in my experience, most people will have no idea what the actual limits for the engines in their knackered old Cessna 150s and 152s are.

They'll almost all be flying the aircraft outside of their certified weight & balance envelope (indeed, when I did my skill test, the examiner from the CAA, who was 6 ft tall and not exactly thin, looked over my shoulder as I performed the weight & balance calculations and told me that he weighed 4 stone - which made us "legal" - to which the response was of course "yes sir", given that I wanted my PPL). Very few of them will perform as well as the book says they should, and a lot of the time they'll be "cruising" with the throttle crammed into the firewall (for the first few weeks of my PPL I actually had the Cessna throttle shape embossed into my hand...).

None of this is good, but it is reality.

People get away with it because the engines are pretty much agricultural (and the airframes are forgiving). They drink fuel and oil at a prodigious rate, they have a pretty low piston speed, are naturally aspirated and actually quite heavily built.

That O-360 makes about 180 bhp, which is only 0.5 bhp/cubic inch.

The O-360 has a stroke of 4.375 inches and turns at a maximum of 2700 rpm. This gives a mean piston speed of 1968 feet per minute. The TBO is about 2000 hours.

An early Merlin on 100 octane fuel had a combat rating of about 1300 bhp from its nominal 1650 cubic inches, which is 0.78 bhp/cubic inch. Late war engines on 150 grade were putting out about 2050 bhp for war emergency, which is almost 1.25 bhp/cubic inch.

The Merlin has a stroke of 6 inches, and turns at a maximum of 3000 rpm, giving a mean piston speed of 3000 feet per minute.

The nominal overhall life of a a fighter Merlin was 240 hours at the start of WWII, increasing to 300 hours (360 for twins) at the end. A substantial proportion of engines didn't make it to their nominal life.



The military would accept rather higher accident rates in wartime than anybody (regulator, manufacturers, pilots) would accept for GA flying in peacetime. So if you wanted to match the engine failure rates without de-rating or changing the usage schedule you'd probably end up with considerably shorter overhaul lives.

The fact is that the margins in GA are sometimes pretty generous.

A couple of renewals ago, I had to fly off some hours, so I bashed the circuit in a PA-38. It was a beautiful sunny day, about 15ºC with some reasonably strong thermals and quite large cumulus development; I rather regretted not being in a glider. The engine was sometimes a little sluggish when I opened up to touch & go, but nothing dramatic.

The next day I went in to the flying school to do some more hours and got asked all manner of pointed questions about whether I had checked the carb heat before I flew, which of course I had. It turned out that some time after I checked it, the cable broke, and I'd been flying touch & goes for probably the best part of an hour without it in almost perfect carb-ice conditions.

Does this mean that you can get away without using carb heat? Certainly not. But it illustrates the fact that failure to do so doesn't cause instant/rapid, guaranteed engine failure (as it does in some flightsims, such as X-Plane). [I]It just increases your exposure to risk.

The point here is that IRL there is no re-fly button. This dramatically changes the way in which the average person will behave.

If you've got a 1% chance of having to hit re-fly because of questionable decision, most people will shrug their shoulders and press on. Swap that out for a 1% chance of actually being killed, and a lot of people would change their behaviour.

For example, it's a legal requirement in most places that you wear a seat belt when travelling by car. But even in places with really bad road traffic accident rates, most people would expect to manage more than 100 journeys between even minor crashes.

To put it another way, imagine for a moment that 1c make the Wellington flyable in a future expansion. IRL, RAF bomber command sometimes suffered a 10% loss rate. This was unsustainable, both for reasons of morale (given that the probability of surviving a tour was therefore pretty low) and also for the simple practical reason that it was difficult for the training organisation to produce sufficient crew to replace those losses. Very few people would want to step into a bomber pilot's shoes IRL.

But if you look at the way most people fly online, they'd consider a 10% loss rate per sortie to be somewhere between good and excellent (though they'd find the actual flying to Germany and back very very boring, given that almost 90% of the time nothing much would happen, and they'd probably bomb an empty field due to the limitations of their navigational abilities).


http://www.vansaircraft.com/pdf/Hartzell_c2yk.pdf

This isn't really especially dramatic. 8700 hours is quite a lot of life.

It seems to me that this document is largely aimed at lawsuit avoidance.

I'm not saying that the information it contains isn't valid & important, but we're really talking about different orders of magnitude of safety margin from those associated with WWII aircraft and engines; compare and contrast with the nominal overhaul life of a Merlin.


It is much better to be down on the ground wishing you were flying than flying and wishing you were down on the ground.
Amen to that. But if you get away with it then it's an extremely effective learning experience.


It amazing that most gamers just think changing a few parts is no big deal.
That's because they don't have to pay the bill!


They don't seem to understand the low safety margins required for flight. Facts are it is the simple things that can kill you in aviation because of those low margins.

Yes, but most of the time they don't. One of the biggest problems in aviation safety today is that aviation is safe enough that people get complacent, and this makes it very difficult to improve the accident rate, because people feel safe enough to cut corners, and Smeed's law (http://en.wikipedia.org/wiki/Smeed%27s_law) comes into play. This seems to be especially the case with helicopters, which have suffered a stagnant accident rate for quite a while. People just seem to have collectively accepted that helicopters crash far more regularly than fixed wing aeroplanes, shrugged their shoulders and elected to either take the risk or (in a minority of cases) avoid using helicopters.

I get the strong sense from reading accident reports that quite often people get themselves killed after putting their head into the tiger's mouth dozens or even hundreds of times, probably without even knowing that was what they were doing.

Some people smoke for a lifetime and don't get lung cancer. Some people never smoke and do. Likewise, some people do stupid things with aeroplanes for a lifetime and get away with it, and some people are just downright unlucky, and get killed through no fault of their own.

The latter group are thankfully in a tiny minority, and the size of that minority is subject to reduction via the application of what may broadly be termed "engineering methods".

But it's very hard to prevent people from killing themselves through stupidity, because idiots are both persistent and ingenious.

I'm at an entirely post graduate university. At a minimum, everybody here has at least a BSc; a substantial proportion have enough degrees to make a rudimentary thermometer, and most speak multiple languages. So these are clever, well educated people. But an amazing proportion of them smoke. Wandering around the place, you'll see them clustered outside doorways sucking on their cancer sticks. Even outside the healthcare building, where there are so many smokers that they've had to put up signs to remind them not to litter the place with cigarette butts. Not that they seem to take much notice.

That basically sums up the general problem with risk. Once things get safe enough that people don't see their peers dying around them as a consequence of questionable risk management, they tend to just go with the flow and get into bad habits, even if they objectively understand that they're taking risks.

By the time the population of post-graduate smokers start to suffer an increased cancer rate, not only has the damage been done, but a lot of them will have become so habituated to smoking that they'll have real difficulty stopping, because of course by then their friends will contain a disproportionate number of smokers, and if they quit then they'll be left alone whilst the smokers all go outside to suck their cancer sticks. I've watched this happen to several of my friends. They start smoking, then all their friends smoke, their girlfriend smokes, and so when they quit they suddenly find their whole peergroup basically ostracises them for a large amount of the time whilst they all go outside to smoke. So unless a majority of the group decides to quit, they can't make it stick.

Also, people are generally happy to take a large number of small risks (for the same total risk exposure) than a small number of big risks.

So the smokers will happily gradually erode their life expectancy one cigarette at a time, but if you could arrange to lump even about a year's worth of smoking risk into one event, they'd probably feel much less comfortable. I suppose this is due to perceived variance.

In a similar way, some pilots will happily take lots of small risks (e.g. pushing decision heights a little), despite the fact that if you re-arrange the overall risk into one big hit (e.g. by saying, "if you guarantee never to take this small risk again, I'll give you a one-time-only get-out-of-jail-free-card to fly under/through Tower Bridge, the Eiffel Tower or some other suitably dramatic landmark of your choice - you can even do it upside down if you want!") they'd feel very uncomfortably about taking it.

Overall, aviation safety has now reached a point where a lot of people do questionable things without seeing consequences, and so they build up bad habits, and don't feel uncomfortable about them. I've seen people at some gliding clubs move powered aeroplanes by pushing or pulling on the prop. It makes me feel extremely uncomfortable. Especially when I challenge them and they say things like "It's OK because I checked that the switches in the cockpit were off".

In fact, the people who do behave sensibly are made to feel uncomfortable because they're abnormal. Walk out to a club aeroplane wearing a flying suit, flying boots, gloves and a parachute, and people will make snide comments.

I think that at some level it reminds them of their own mortality. Personally, I've never used my parachute, and I hope I never will. The flying gloves are a pain most of the time. But if the aeroplane were to catch fire, the gloves would protect my hands, giving me much more time to get out, and if I used my parachute then the boots greatly reduce the chances that I'll break an ankle on landing.

Therefore I'll gladly suffer the inconvenience 99.999999% of the time, just in case one day I find myself on the 0.000001% flight.

I'll also actually wait 2-3 minutes after a jet airliner has landed before using the same runway to takeoff, even if the controller moans at me, because clearance to takeoff does not magically guarantee that it's safe or sensible.

But I'm not your average GA pilot.

TL;DR I don't think that you can make a direct comparison between modern civil aviation and 1940s military aviation.
I also don't think that you can expect people to react to game risks in the same way as they would react to real-life risk.

[Seadog]

YES it does Seadog. It is the two different sets of instructions.

First the pilot logs the event of using Emergency Power. THEN the mechanic must inspect the motor and return it service.



Show us an order where an inspection is mandatory and not discretionary.

You haven't done that and can't because inspection was discretionary based upon the pilot's reports and log book entries.

I really can't believe that you would continue to argue this when the facts, from 3 separate documents show that reporting was mandatory but inspection was discretionary.

[Blackdog_kt]

I don't mind them reacting to in-game risk by treating their ride in a rough manner.

I just want them to have consequences for it when flying under higher difficulty settings.

What the consequences should be within the frame of a computer game is what this thread is about.

We're not here to discuss how long it takes for a particular engine to fail. We're here to discuss how to integrate consequences for reckless operation of the airframe into a new game mechanic/feature.

This following part is not directed to anyone in particular, it's just a very visible trend lately on these here forums.

There seems too many people whose sole purpose seems to be running their preferred warbird at top performance for no cost. This is not a problem.

What is a problem is the apparent desire of some to have this happen across the board, regardless of realism/difficulty settings, so that they can fly on full real servers with their preferred easy-mode button enabled by default, while everyone else flies with limitations in place.

Sure, let's have a constant +12lbs Merlin in the sim. Let's have a constant 1.45 Ata DB601 too and whatever the Me-110s used to run with their better performing DB601Ns (which are not even modeled currently), something which would suddenly make the 110 the fastest one of them all. Fun times and varied gameplay, huh? Well, not so much.

For a sim that's been so criticized for sharing a lot of commonalities with the previous IL2 series, there's an awful lot of people who expect to carry their IL2 flying habits into the new series without any need to adapt their tactics and without any cost whatsoever to their preferred way of flying and fighting.

Sure, they should have the option to do it. Keyword here is option. Turn down CEM and temp effects if you want and red-line the thing all day long. Just don't force me to play the same way. It's not a social stigma to fly on less that full difficulty you know :rolleyes:


I'm with Kurfurst on this one. There needs to be a way to limit such behaviour by the player if they choose to fly under such difficulty settings, because otherwise

a) we have a repeat of IL2:1946 where everyone flies on full boost all the time just because we can and

b) this greatly skews the historical balance of things

No matter the accuracy of the FM, if i'm tooting around with a constant 30% more horsepower than the real guys did, then all the variables that govern the fight take a jump for the historically inaccurate: i climb higher at an earlier point in time, i have the jump on the enemy with less effort, i don't need to look into the cockpit and suffer reduced SA because i know the engine can take it even if i don't look at the gauges, i can pull more G's during a fight, last longer in a zoom climb or vertical scissors and so on and on and on.

Meanwhile, what really happened is that the extra 30% was only used when absolutely essential to someone's survival. Otherwise, they were milling around with lower power settings and relied on interesting stuff like the element of surprise, proper tactics and getting a kill in one pass before scooting off to reposition for another pass from a favorable location.

This is leaps and bounds away from what we had in IL2:1946, where people could either furball it on the deck at low airspeeds and full throttle with no penalty whatsoever, or boom and zoom like rocket-ships without worrying about all the nasty stuff that can happen in a high speed dive and a subsequent zoom climb, like freezing your carbs, shock cooling, tearing off your cowl flaps or run the engine rough for any number of reasons and be left wallowing during the zoom back up like a sitting duck.

CoD gives us a way to get one step closer to how these battles were really fought. If that's not glamorous enough for some then it's ok, there are difficulty settings they can adjust to tailor it to their taste. Better yet, let's get a "IL2:1946 mode" in the realism options that automatically disables all the cool new stuff so people can fly without having to learn anything new or change their habits.

I'm perfectly fine with it, as long as they don't try to impose it on everyone else. I want my engine to fail and i want your engine to fail if we don't know what we're doing. If you don't want it like that, fly on a different server with different settings, problem solved ;)


In summary, i don't care what each engine could run and for how long. All i care about is that the real pilots back then didn't fly like that for a host of different reasons. I want a set of restrictions in place that will force the player to do the same if he enables the relevant difficulty settings. This is what this thread is all about, not technical specs and charts.

[Seadog]

In summary, i don't care what each engine could run and for how long. All i care about is that the real pilots back then didn't fly like that for a host of different reasons. I want a set of restrictions in place that will force the player to do the same if he enables the relevant difficulty settings. This is what this thread is all about, not technical specs and charts.

I beg to differ:


https://lh4.googleusercontent.com/-davSCMq7xVI/Te_o6mbKqkI/AAAAAAAAABA/NDvJL5xfi8k/s512/OB_5min%252B.jpg

from:
http://www.wwiiaircraftperformance.org/hurricane/145-dutton-1july40.pdf

In real life pilots would risk all for a kill or to stay alive.

[ICDP]

Seadog no matter how many charts you produce the fact remains that there WAS a limit imposed on the use of +12lbs boost. Even the charts you produce sate that use of +12lbs boost MAY shorten engine life. The fact that an engineer was to assess for potential damage after +12lbs boost was used is a bloody good indicator that potential damage could occur. Not definately damaged but MAYBE damaged, after eventual inspection it may be found that engine is perfect but it didn't mean the potential for damage wasn't there. It doesn't matter if an inspection was mandatory or recommended or even to be contemplated, the fact remains that use of +12lbs boost EVEN FOR A FEW SECONDS, DID require the pilot to make a note in the flight log. It was then up to the engineer to determine if the engine needed overhauled based on the fact that +12 boost INCREASED THE RISK OF DAMAGE. He would not be under orders to do this if there was not some good bloody reason for it.

Not one single person replying to your posts is saying a Merlin will break as soon as 5 minutes at +12lbs boost has passed. We are saying the potential for damage was increased the longer it was used. If you don't want to damage your Merlin then turn off CEM. The rest of us will keep it as close to real as possible.

[Seadog]

Seadog no matter how many charts you produce the fact remains that there WAS a limit imposed on the use of +12lbs boost.

It doesn't matter if an inspection was mandatory or recommended or even to be contemplated, the fact remains that use of +12lbs boost EVEN FOR A FEW SECONDS, DID require the pilot to make a note in the flight log. It was then up to the engineer to determine if the engine needed overhauled based on the fact that +12 boost INCREASED THE RISK OF DAMAGE. He would not be under orders to do this if there was not some good bloody reason for it.

Not one single person replying to your posts is saying a Merlin will break as soon as 5 minutes at +12lbs boost has passed. We are saying the potential for damage was increased the longer it was used. If you don't want to damage your Merlin then turn off CEM. The rest of us will keep it as close to real as possible.

P/O Dutton chose to ignore the 5 min limit. I doubt he was court martialed or penalized in anyway for doing so and his engine may have been a candidate for inspection (as he combined steep dives with overboost), but I doubt he lost any sleep over that.

There is a poster who is claiming that any use of 12lb/3000rpm will result in grounding till a mandatory inspection is done, and I'm glad to see that you disagree with this.

Again, this is exactly what I've been saying. Keep your gauges in the black and 5min+ at 12lb/3000rpm results in increased but still minimal ("low probability") risk, but it is completely ahistorical to claim that pilots did not use 12lb/3000rpm repeatedly or for more than 5 mins as the situation warranted. We know that in the real battle pilots weighed the risks and then "pulled the plug" and some were willing to keep it pulled for more than 5 mins and the game should allow this even with CEM, because that's the way things were. RAFFC went to 100 octane fuel precisely because it allowed the use of 12lb boost and this gave RAFFC a vital edge in performance when it was needed, and some even state that this was the difference between defeat and victory:

V. A. Kalichevsky, author of the 1943 book The Amazing Petroleum Industry wrote:

It is an established fact that a difference of only 13 points in octane number made possible the defeat of the Luftwaffe by the R.A.F. in the Fall of 1940. This difference, slight as it seems, is sufficient to give a plane the vital "edge" in altitude, rate of climb and maneuverability that spells the difference between defeat and victory.

Why bother with a game that goes to great lengths to accurately model aircraft performance, but then takes away the winning edge that 100 octane fuel (despite all the sweat and cost that RAFFC went to make sure that they could take advantage of it) provided during the battle?

[Crumpp]

It's the prop that might fail, not the engine.

The way i presented the example caused your confusion. It is not one thing but two seperate issues. The Hartzell bulletin has nothing to do with take off rating of the engine. It just illustrates how seemly minor changes can have catastrophic effects.

A Lycoming O-360 is take off rated and you don't use it except for take off. That is an engine limitation.

The Hartzell bulletin is talking about specific O-360A1A's equipped with a specific hub/blade combination AND using Lightspeed's Engineering electronic ignition.

Your next point, of course I meant inches of mercury. It does not matter though...you don't exceed the 28 on the EFIS!! :)

http://img847.imageshack.us/img847/3766/efis.jpg (http://imageshack.us/photo/my-images/847/efis.jpg/)


So I would modify your first statement to say that

have to ask who cares and what is point of this portion of your reply? Are you trying to educate me on TBO determination? It is a fact that sometimes TBO are very arbitrary and not based on any real engineering at all. Why? The company does not spend the money or the time or have enough data.

Many times manufacturer's set them very low at first and then raise them as field experience is gained. Rotax 912 is a modern example.

Everyone is expecting the Centurion Diesels to see a TBO raise too. They did the same thing.

http://www.centurion-engines.com/typo3/index.php?id=2&L=1

What is important and seems to get covered up in your reply Viper is the following:

Pilot's fly airplanes IAW the Operating Instructions published by the manufacturer.

End of message.

Anything else is baloney and thinking like a gamer, not a pilot.

Engineers do this because it is generally assumed that pilots can't be trusted to obey the limits in the Pilot's Notes. Sad but true.

I would say this baloney in all my real world experience both in college, PIC, and in maintenance of aircraft. I don't know of any RL pilots who condone exceeding published limits at all. It is not the engineers life on the line.

I certainly don't know any licensed A&P's who think that way or do not follow publications. That is good way to kill somebody, lose your rating, and even go to prison. There are shady folks in aviation. One owner and he FBO are in the process of suing one such individual right now. That is if the sheriff does not get to him first.

In reality, not following published procedures can and will kill you. The FAA statistics show this quite nicely.

The reality is only a tiny fraction of the community knowingly violate procedures. Most understand the importance and the consequences of not following it.

I knew this pilot. He was VERY professional and flew his aircraft by the numbers. Nothing he did in an airplane was unplanned or "seat of your pants".

He died because he did not change his altimeter setting. He made a simple mistake and did not follow procedure to monitor ATIS and adjust the altimeter accordingly. He entered a loop and end up with CFIT.

http://www.youtube.com/watch?v=rLDiPEgysYI

You should know the old axiom, "There are Old Pilots and there are Bold Pilots but there are not any Old and Bold Pilots!"

It got to be a axiom because it spells out the truth.

None of this is good, but it is reality.

Your reality is far different from my experiences. I have to take your comments about the 152's and flying outside of CG and everything else with a grain of salt or at least it does not apply to General Aviation in the United States.

Of course there are almost 20,000 airports to land at in the United States. I can find a convenient airport at almost any destination I choose. In the EU, you have just over 2500 airports to land at.....

It is impossible to compare the General Aviation community as GA is a completely different animal in the EU.

Perhaps when the EU GA community matures, it can begin to keep statistics to help make the pilot community safer. Maybe then your civil pilot population will become more educated and not act so recklessly.

As regards to safety, the partial data available gives only some indication as to the main causes of fatal accidents. There are no European wide comprehensive statistics on safety of General Aviation Aircraft

http://www.epats.eu/Files/Deliverables/EPATS%20D1.1-RoEB&PADBase-V1.pdf

Continental did that because they did not test or design the engine for any higher rating. When the O-520 first came out, the crankcase was too light even at maximum continuous and there were many failures as a result. Subsequently Conti went to steel on steel for their rings and now very few of them make it to TBO without a top end.

In short, the engine has had too troubles at it's current rating to even think about a manifold pressure increase.

It is also not tolerant at all of improper procedures. Feel free to invest your money in an O-520 and then not follow the book. :p

If the installation has plenty of power, there is no need for a Take Off rating. The Lycoming O-360 has been adopted to so many installation that including many heavy twins. That little 180 hp engine pulls some weighty airplanes around now. The O-360 series is a close to bullet proof as you can get in a light aircraft engine. I wouldn't trade mine for all the tea in china.

[Crumpp]

I beg to differ:


I pulled the plug is an expression not a rating. You don't know what throttle setting the pilot used or for how long.

[Blackdog_kt]

I beg to differ:


https://lh4.googleusercontent.com/-davSCMq7xVI/Te_o6mbKqkI/AAAAAAAAABA/NDvJL5xfi8k/s512/OB_5min%252B.jpg

from:
http://www.wwiiaircraftperformance.org/hurricane/145-dutton-1july40.pdf

In real life pilots would risk all for a kill or to stay alive.

Mate, fly like you want to, i'm not here to tell you how to enjoy the sim. I just don't want to do things the same way you do, so i'm asking for a difficulty/realism option that allows us both to get what we want by deciding if we will toggle it on or off.

Again, this is not a thread about what, it's a thread about how: how do we impose some kind of limit on the gamer-pilot's ability to exceed published limits in a way that's not totally artificial and detracting from immersion, while at the same time giving a realistic amount of inconvenience for those of us who choose to overstep the boundaries.

I'm not asking for an artificial limit the likes of "5 minutes plus 1 second of emergency power, sorry your engine's toast". It's exactly what i disliked most about the IL2 engine management in the previous series, with it's resettable overheat timer of 5 minutes: run around at full power, overheat message comes up and you now have 5 minutes before damage occurs, chop throttle and open rads to rapidly cool the engine, the 5 minute timer is reset without damage to the engine, rinse and repeat.

It's too cut and dry, too artificial, completely unrealistic and since it's 100% predictable behaviour it allows us to game the game.

I'm just saying there needs to be a drawback that attempts to simulate what actually happened: it was perfectly possible to exceed the limits with no consequence for a lot of times, then have it bite the pilot in the behind one time out of many.

A good way to do this is Kurfurst's suggestion, because it provides some sort of "continuity of airframe" between sorties. It won't magically prevent me from running +12lbs all day long, it will just make it easier for my engine to suffer damage in subsequent sorties if i do. Throw in a 5% randomization for the relevant parameters and we got a good solution: i can exceed the limits but there's no cut and dry consequence every time, instead there's uncertainty and this enhances gameplay through a heightened sense of thrill and the need for improved tactics that will mitigate the risk of having to engage WEP.

Roll it into a nice option in the realism settings, let server admins chose an accelerated wear and tear model to give us a condensed snapshot of possible engine issues without having to fly a thousand sorties before something interesting happens and we're good to go. If people don't want to use it they join a different server and everyone's happy again.

So please, can we get back on the topic of how to achieve something like this?

[Crumpp]

V. A. Kalichevsky, author of the 1943 book The Amazing Petroleum Industry wrote:

The author might know about petroleum but he certainly does not know about engines or was not aware of the Germans direct fuel injection.

I don't see what the point is other than a book during the war offers a glimpse into the thinking of the time.

I suppose we could take the eugenics theories of the day as fact too??

[ICDP]

P/O Dutton chose to ignore the 5 min limit. I doubt he was court martialed or penalized in anyway for doing so and his engine may have been a candidate for inspection (as he combined steep dives with overboost), but I doubt he lost any sleep over that.

What? Who the hell mentioned court martials? Is English not your first language?

There is a poster who is claiming that any use of 12lb/3000rpm will result in grounding till a mandatory inspection is done, and I'm glad to see that you disagree with this.

I don't entirely agree with his stance, nor do I agree with yours that an engineer could just shrug his shoulders and say don't worry about it. ALL engines regardless of what boost was used were inspected at the very least at the end of the days flying and preferably at the end of each flight timing permitted. Using +12lbs boost was by your own admission enough to warrant an inspection at the earliest possible convenience. The earliest possible convenience would be that very evening in the worst case scenario. When doing the routine maintenance at the end of each evening the engineer consults the logbooks of all aircraft flown that day. He sees that this particular aircraft has an entry that the pilot used +12lbs boost. He knows from his orders (Straight from Dowding) that it is SOP to do a more thorough check for wear and tear. Do you now dispute this?

Again, this is exactly what I've been saying. Keep your gauges in the black and 5min+ at 12lb/3000rpm results in increased but still minimal ("low probability") risk, but it is completely ahistorical to claim that pilots did not use 12lb/3000rpm repeatedly or for more than 5 mins as the situation warranted. We know that in the real battle pilots weighed the risks and then "pulled the plug" and some were willing to keep it pulled for more than 5 mins and the game should allow this even with CEM, because that's the way things were. RAFFC went to 100 octane fuel precisely because it allowed the use of 12lb boost and this gave RAFFC a vital edge in performance when it was needed, and some even state that this was the difference between defeat and victory:

We know it was used, we also know it was used for longer than 5 minutes per flight on occassions. Everyone here actually agrees that it could be used and that there was an increased risk. Why do you keep this up, here it is again in big writing. Sorry for shouting but this point is very important.

WE ALL AGREE THAT USING +12LBS BOOST COULD BE AND WAS USED LONGER THAN 5 MINUTES BUT IT WAS NOT A RISK FREE ACTION.

Why bother with a game that goes to great lengths to accurately model aircraft performance, but then takes away the winning edge that 100 octane fuel (despite all the sweat and cost that RAFFC went to make sure that they could take advantage of it) provided during the battle?

Ah the bias starts to show. What you want is some "click here = win" button for the RAF? +12lbs boost gave a boost in performance, it was not a massive advantage that guaranteed victory. Even with +12lbs boost the difference in performance between a Spitfire, 109E and even a Hurricane were close enough that surprise, tactics and pilot skill was the determining factor in the outcome of any engagement.

[Kurfürst]

Why bother with a game that goes to great lengths to accurately model aircraft performance, but then takes away the winning edge that 100 octane fuel (despite all the sweat and cost that RAFFC went to make sure that they could take advantage of it) provided during the battle?

I have a funny picture for Mr. Kacys-whatever, who seems to think 100 octane was only on the British side. Note the funny triangle behind the cocpit, and the numbers written on that. It shows what kind of fuel the plane is to be filled up with.

http://www.kurfurst.org/Engine/DB60x/files/109E4N_20Sept1940b_DFC.jpg

[Crumpp]

http://img585.imageshack.us/img585/3662/c3inthebob.jpg (http://imageshack.us/photo/my-images/585/c3inthebob.jpg/)

[Seadog]

I don't entirely agree with his stance, nor do I agree with yours that an engineer could just shrug his shoulders and say don't worry about it. ALL engines regardless of what boost was used were inspected at the very least at the end of the days flying and preferably at the end of each flight timing permitted. Using +12lbs boost was by your own admission enough to warrant an inspection at the earliest possible convenience. The earliest possible convenience would be that very evening in the worst case scenario. When doing the routine maintenance at the end of each evening the engineer consults the logbooks of all aircraft flown that day. He sees that this particular aircraft has an entry that the pilot used +12lbs boost. He knows from his orders (Straight from Dowding) that it is SOP to do a more thorough check for wear and tear. Do you now dispute this?

First off, Dowding's memo states that oil filter checks were mandatory, "when convenient" for aircraft that exceeded 5mins at 12lb/3000rpm:

Let's be very clear on this point.:

https://lh6.googleusercontent.com/-w0KMFkD0Y2I/TfEUpnUem-I/AAAAAAAAABM/FF2lUEdK7nE/s640/engine_limits.jpg


Ah the bias starts to show. What you want is some "click here = win" button for the RAF? +12lbs boost gave a boost in performance, it was not a massive advantage that guaranteed victory. Even with +12lbs boost the difference in performance between a Spitfire, 109E and even a Hurricane were close enough that surprise, tactics and pilot skill was the determining factor in the outcome of any engagement.

No, want I want is historical accuracy. The Luftwaffe and RAF were locked in a constant technology battle that eventually saw the Luftwaffe field the Fw-190 when the RAF still had the Spit V and then the Me-262...but in 1940 the use of 100 octane fuel gave RAFFC greater power output at medium and low altitudes, when needed. This was the historical situation and I want the sim to reflect it.

I have read through every source on the Merlin engine that I have, and all the combat reports at:
http://www.wwiiaircraftperformance.org/
From what I can gather, Merlin engine failures, were primarily random events and the main culprit was manufacturing defects/design faults that eventually break the engine. The 50 hour 12lb/3000rpm test is an example of this, where the engine was cycled 100 times at 5min/20min at 12/4.5lb boost and eventually developed a coolant leak from a defect that plagued service engines that were not being run past 6.25lb.

The Merlin in Perspective states that fighters had a higher propensity for coolant leaks than bombers because fighters were cycling engine power from very low to very high much more frequently, but this was still not a common occurrence.

The next greatest problem was bearing failure from oil starvation, and again 12lb boost had little to do with this except for prolonged steep climbs, as per Dowding's memo, but probably the greatest cause was inverted flying and prolonged dives that caused excessive (~3600) RPM.

1939 Merlin TBO:
Fighters: 240 hrs
Bombers: 300 hrs

repair depots:
1942 onward: 35% of engines were there due to time expiry.

1942 onward: average engine under repair had 60% of nominal life, or 144 hrs for a fighter engine and 180 hrs for a bomber engine.

I would propose the following:

Any engine has a 65% probability of random major engine failure, during 240 hrs of operation, or about 160 sorties. Another way to express that would be a 6.5% probability of one aircraft out of 16 having major engine failure on a typical mission. I don't know how to model the use of 12lb/3000 rpm for more than 5mins, but a simple way would be be multiply the failure probability by, say 1.15, to simulate the increased RPM and stress on the engine.

[Crumpp]

First off, Dowding's memo states

Who cares? The published Operating Instructions and Technical Orders for the Spitfire are clear. Dowding was not the technical expert on Rolls Royce engines. He had people to fill that role for him and he followed their advice.

It is a fact, ANY use of +12lbs in the Merlin engines requires a log book entry and a mechanics inspection before the engine is returned to service.

You seem to think that having the engine inspected after the extreme stress of over boosting is uncommon.

Almost every fighter aircraft engine in WWII had to have it done.

BMW, Diamler, Rolls Royce, Allison, and just about every else required it. It only makes practical sense.

Even OUR P51D Merlin had the same instructions:

http://img853.imageshack.us/img853/4386/p51wep.jpg (http://imageshack.us/photo/my-images/853/p51wep.jpg/)

I think you just want a magic win button for your game.

[Seadog]

Who cares? The published Operating Instructions and Technical Orders for the Spitfire are clear.

They certainly are clear and Dowding's memo leaves no room for doubt.



Dowding was not the technical expert on Rolls Royce engines. He had people to fill that role for him and he followed their advice.

He certainly did, which is why the memo is worded the way it is.


It is a fact, ANY use of +12lbs in the Merlin engines requires a log book entry and a mechanics inspection before the engine is returned to service.

You seem to think that having the engine inspected after the extreme stress of over boosting is uncommon.

Almost every fighter aircraft engine in WWII had to have it done.

BMW, Diamler, Rolls Royce, Allison, and just about every else required it. It only makes practical sense.

Even OUR P51D Merlin had the same instructions:



I think you just want a magic win button for your game.



War emergency power on a Mustang!!!? The Mustang/Merlin 60 series was not the same as 12lb boost on a Merlin III:


67 inHg = +18 lbf/in² boost
61 inHg = +15 lbf/in² boost
46 inHg = +8 lbf/in² boost
44.5 inHg = +6 lbf/in² boost

so they are talking about pulling 18lb boost and 1700hp from a Merlin Engine with a two stage SC, or about 30% more power than a Merlin III at 12lb boost.

The Normal full throttle setting on the Mustang is 61" boost or 15lb boost and at that setting no extra inspection is required.

The Merlin XII was cleared for 12lb boost on T/O, so this was simply normal operations for a Spit II

[Blackdog_kt]

All i know is that takeoff power or emergency power is called that way for a reason: it is to be reduced to lower levels under all other regimes of flight.
Otherwise they would just call it full power and be done with it.

The mustang's 67" of MP is equivalent to the Spits +12lbs, the 109's 1.45 Ata and so on and so forth, take your pick, in the sense that they are not meant to be ran for eternity because things will start to break. Maybe not on this sortie or the next, but definitely something will give after a few missions, especially if i push it that way on every single sortie and the mechanics follow your reasoning of not inspecting it afterwords :-P

As another example, for later mark Spitifires like the Mk.IX it was advised to take off with a mere +9lbs no matter if it could do +12, +16 or +25 and that's a pretty critical phase of flight in terms of power reserves in case something goes wrong.

If they didn't slam the throttle to the stops on takeoff that's telling me that full power at low airspeeds was a combination for insufficient cooling, overheat and eventual engine seizure if the oil dissolved. True, this is for later mark Spits with a higher power output, but these also had an extra radiator to help with cooling which our in-game early Spits lack, so it's more or less a trade-off.

All that is enough explanation for me to convince me that operating limits are there for a reason. I want a difficulty setting that imposes penalties if i exceed them, that's all. If you don't like it, feel free not to use it.

However, the majority of people in the community won't stand for implementing changes to the FM/DM that have all other aircraft adhering to some kind of limits while the Spitfires suffer none and it's not even for balancing reasons. It's because it's common sense to assume that emergency and takeoff power are named that way for a reason.

Can we please get back on the topic of how such a game mechanic/feature could be implemented? If you want to continue debating if +12lbs classified as emergency power, feel free to start a different thread about it, you're just being off topic in this one:

The current thread is not about "what can the Merlin run with impunity?". The topic is "how do we punish the player that exceeds what the engine can reasonably run, if he chooses to enable the relevant difficulty/realism settings". It's about ALL engines, not just the Merlin.

[Crumpp]

All i know is that takeoff power or emergency power is called that way for a reason: it is to be reduced to lower levels under all other regimes of flight.
Otherwise they would just call it full power and be done with it.

Exactly.

how such a game mechanic/feature could be implemented?

The most realistic thing your game could do to simulate it is just have the engine start losing power gradually.

The most common sign of engine wear in RL is inability to develop full rpm and loss of compressions.

This is not a dramatic event and is why compression checks are done at annual at a minimum. A compression check would be in order after running an engine at Emergency power.

The longer a player left the "emergency rating" engaged beyond Operating limits, the more rpm and compression he would lose.

My 2 cents...

Here is what Lycoming's Key Reprints have to say about following the Operating Procedures in their engines:

Pilot technique is another factor affecting engine life. Following manufacturer recommendations could be categorized as good operation. On the other hand, complete disregard for these recommendations could conceivably cause engine destruction in as little as 100 hours. Although this would be extreme and unusual, pilots who regularly climb at steep angles, make abrupt throttle changes, improperly lean the engine in climb, exceed maximum specified manifold pressure and/or RPM, chop throttles abruptly and let down rapidly causing rapid contraction of metals that have been up to operating temperatures are using techniques that may shorten TBO.

http://www.lycoming.com/support/tips-advice/key-reprints/pdfs/Key%20General.pdf

[Crumpp]

They certainly are clear and Dowding's memo leaves no room for doubt.

Then you should find those same instructions in the Operating Instructions.

However that is not the case.


The Operating Instructions are clear. The pilot must log the event, the mechanic must inspect the engine and return it service.

[Seadog]

The mustang's 67" of MP is equivalent to the Spits +12lbs, the 109's 1.45 Ata and so on and so forth, take your pick, in the sense that they are not meant to be ran for eternity because things will start to break. Maybe not on this sortie or the next, but definitely something will give after a few missions, especially if i push it that way on every single sortie and the mechanics follow your reasoning of not inspecting it afterwords :-P


As another example, for later mark Spitifires like the Mk.IX it was advised to take off with a mere +9lbs no matter if it could do +12, +16 or +25 and that's a pretty critical phase of flight in terms of power reserves in case something goes wrong.



[/b]


The Spit 9 was approved for 12, or 18lb boost, on TO depending on the variant:
https://lh6.googleusercontent.com/-U7ldYm2dh_o/TfGOVz89CjI/AAAAAAAAABY/kPVSU7pTVaU/Spit9_engine_data.jpg
The Merlin 61 and 63 were approved for 12lb on T0 and 5MIN at 15.25lb for Combat.

The Merlin 66 was approved for 18lb for TO and 5min at 18lb for combat.

The V-1650-3 and -7 used on the P51-B, C and D was approved for 15.25lb (61") on TO and was basically equivalent to the Merlin 63 but had a special WEP rating of 18lb for 5min, not present on the Merlin 63, so the V-1650 -3,-7 were running beyond the equivalent of 12lb on a Merlin III.

If you try and use 18lb boost on TO, for example, you will end up with major engine torque issues that will make the whole process extremely dangerous, while 9lb will get the Spit off the ground in a very short space and was a lot safer.

Regarding 12lb/3000rpm, I made a solid proposal which is based upon operational data:


I have read through every source on the Merlin engine that I have, and all the combat reports at:
http://www.wwiiaircraftperformance.org/
From what I can gather, Merlin engine failures, were primarily random events and the main culprit was manufacturing defects/design faults that eventually break the engine. The 50 hour 12lb/3000rpm test is an example of this, where the engine was cycled 100 times at 5min/20min at 12/4.5lb boost and eventually developed a coolant leak from a defect that plagued service engines that were not being run past 6.25lb.

The Merlin in Perspective states that fighters had a higher propensity for coolant leaks than bombers because fighters were cycling engine power from very low to very high much more frequently, but this was still not a common occurrence.

The next greatest problem was bearing failure from oil starvation, and again 12lb boost had little to do with this except for prolonged steep climbs, as per Dowding's memo, but probably the greatest cause was inverted flying and prolonged dives that caused excessive (~3600) RPM.

1939 Merlin TBO:
Fighters: 240 hrs
Bombers: 300 hrs

repair depots:
1942 onward: 35% of engines were there due to time expiry.

1942 onward: average engine under repair had 60% of nominal life, or 144 hrs for a fighter engine and 180 hrs for a bomber engine.

I would propose the following:

Any engine has a 65% probability of random major engine failure, during 240 hrs of operation, or about 160 sorties. Another way to express that would be a 6.5% probability of one aircraft out of 16 having major engine failure on a typical mission. I don't know how to model the use of 12lb/3000 rpm for more than 5mins, but a simple way would be be multiply the failure probability by, say 1.15, to simulate the increased RPM and stress on the engine.

[TomcatViP]

One thing that I wld like to see is a parameter including the way player move the throttle fwd and back to simulate the damaging effect of walling the throttle (just like it was on initial release ?)

[Crumpp]

One thing that I wld like to see is a parameter including the way player move the throttle fwd and back to simulate the damaging effect of walling the throttle (just like it was on initial release ?)

That is good idea to reward game players who operate their virtual machine correctly.

Real pilots follow published procedures because they understand the engineering margins are narrow and the procedure is in place to get the best performance from your engine. The procedures are there for a reason, to keep your engine developing the maximum power it can deliver.

In the real world, the penalty for abusing your engine is reduced power and an increased risk of catastrophic failure. It should be the same in your game.

You start out with a given potential for maximum power and as you abuse the engine, that power potential is reduced. By the time you finish slamming the throttle, improper propeller use, mixture control use, supercharging gearing misuse, not adhering to temperature rates, and running the motor over-boosted, you could end up with a 900 hp engine at the end of the sortie. No funny noises, just a gradual loss of power. That means your performance will noticeably degrade as you abuse the engine. That loss would effect the airplanes combat performance.

It is not realistic to consider hours flown or previous abuse. It is a game and cannot simulate such things. You get one airplane and at the beginning of the sortie it is new. Depending on how you treat the engine you could land with the same power potential or you could land a worn out aircraft that is no longer combat effective.

This would have to be clearly published in the game manual along with "proper operating procedures" or the whining would be legendary.

Such a system would reward the players who understand their aircraft and can integrate proper operations with proper tactics. You would have a much better simulation of WWII air combat.

[TomcatViP]

+1

Great! Now who wld make a FM model resulting from a kick in the a$$ from an angry Chief mechanics ?!;)

[Strike]

You know what I'd like to see? That would be really "original" and probably attract more "full-real" guys and let the rookies practice taking care of their planes?

I'd like a system where each fighter base has a set selection of planes.

As a player spawns the plane he selects is withdrawn from the pool and sent into action. (we already have server software that does this for IL-2)

If the player returns to base, this plane will be stored in it's current state (with all damage and wear) and put into maintenance or rearm/refuel rotation to bring it up to 100% again.

So now imagine you are pounding a base in an "all-out huge air-campaign online" server. The players that spawn from that base will eventually wear out their planes and decrease the operational effectivity of it.

In a base-capture scenario this would be essential so that the attackers won't feel that the defenders constantly spawn in 100% airplanes when so many have been "wounded" and limped back to base..

So back on topic to the original poster, this would create a chance that when you select your plane, it could be partially repaired or have significant wear on certain components due to damage and repairs/field-repairs giving it altered performance during the next missions.


It's just a piece of the larger idea of having more things play a role in the large ongoing campaign. Imagine airfields depending on factories to replenish them with brand new aircraft, ammo, fuel, spare parts etc so that it would be essential to protect these factories in order to keep the war going! Raiding trains/shipping would also cause the amount of supplies that make it to the frontline to decrease.

World war II online anybody? Yes, but in theory it could be applied with success here too :)

[Blackdog_kt]

That is good idea to reward game players who operate their virtual machine correctly.

Real pilots follow published procedures because they understand the engineering margins are narrow and the procedure is in place to get the best performance from your engine. The procedures are there for a reason, to keep your engine developing the maximum power it can deliver.

In the real world, the penalty for abusing your engine is reduced power and an increased risk of catastrophic failure. It should be the same in your game.

You start out with a given potential for maximum power and as you abuse the engine, that power potential is reduced. By the time you finish slamming the throttle, improper propeller use, mixture control use, supercharging gearing misuse, not adhering to temperature rates, and running the motor over-boosted, you could end up with a 900 hp engine at the end of the sortie. No funny noises, just a gradual loss of power. That means your performance will noticeably degrade as you abuse the engine. That loss would effect the airplanes combat performance.

It is not realistic to consider hours flown or previous abuse. It is a game and cannot simulate such things. You get one airplane and at the beginning of the sortie it is new. Depending on how you treat the engine you could land with the same power potential or you could land a worn out aircraft that is no longer combat effective.

This would have to be clearly published in the game manual along with "proper operating procedures" or the whining would be legendary.

Such a system would reward the players who understand their aircraft and can integrate proper operations with proper tactics. You would have a much better simulation of WWII air combat.

This is a good suggestion for "brand new aircraft each sortie" gameplay mode.



You know what I'd like to see? That would be really "original" and probably attract more "full-real" guys and let the rookies practice taking care of their planes?

I'd like a system where each fighter base has a set selection of planes.

As a player spawns the plane he selects is withdrawn from the pool and sent into action. (we already have server software that does this for IL-2)

If the player returns to base, this plane will be stored in it's current state (with all damage and wear) and put into maintenance or rearm/refuel rotation to bring it up to 100% again.

So now imagine you are pounding a base in an "all-out huge air-campaign online" server. The players that spawn from that base will eventually wear out their planes and decrease the operational effectivity of it.

In a base-capture scenario this would be essential so that the attackers won't feel that the defenders don't constantly spawn in 100% airplanes when so many have been "wounded" and limped back to base..

So back on topic to the original poster, this would create a chance that when you select your plane, it could be partially repaired or have significant wear on certain components due to damage and repairs/field-repairs giving it altered performance during the next missions.


It's just a piece of the larger idea of having more things play a role in the large ongoing campaign. Imagine airfields depending on factories to replenish them with brand new aircraft, ammo, fuel, spare parts etc so that it would be essential to protect these factories in order to keep the war going! Raiding trains/shipping would also cause the amount of supplies that make it to the frontline to decrease.

World war II online anybody? Yes, but in theory it could be applied with success here too :)

And this is exactly what i had in mind in terms of how a dynamic campaign should be handled in the future, offline or online. In fact, this might already be possible for someone who knows how to code in C#.

Great suggestions in both cases ;)

[Seadog]

In Nov 1940, the Merlin XX was given "official" approval to use 12lb/3000rpm but strip inspections were not required after its use:
https://lh6.googleusercontent.com/-VTQIj4Dzew4/TfkIjz3Z51I/AAAAAAAAABs/2-UGlUUjWFE/MerlinXX_no_strip%252520-%252520Copy.jpg

The Merlin 60 series engines were cleared for 15 and 18lb boost for combat and again strip inspections were not required after use:
https://lh4.googleusercontent.com/-P0SVdFZCHrU/TfkIj8wT_RI/AAAAAAAAABw/uXlA2e-E42E/s912/Merlin60series_combat_maint_OFclean2.jpg

An oil filter check was recommended, which probably took about 10mins.

The above data is from the Spit 9 Pilot's notes and from a Merlin 60 series maintenance manual.

[ICDP]

In Nov 1940, the Merlin XX was given "official" approval to use 12lb/3000rpm but strip inspections were not required after its use:

The Merlin 60 series engines were cleared for 15 and 18lb boost for combat and again strip inspections were not required after use:

An oil filter check was recommended, which probably took about 10mins.

The above data is from the Spit 9 Pilot's notes and from a Merlin 60 series maintenance manual.

Meaning that at some stage prior to the Merlin XX was introduced strip inspections were required after overboost was used. Good info, it seems +12lbs boost on the Merlin II, III and XII was limited to a short amount of time... oh I don't know, 5 minutes maybe :)

[Seadog]

Meaning that at some stage prior to the Merlin XX was introduced strip inspections were required after overboost was used. Good info, it seems +12lbs boost on the Merlin II, III and XII was limited to a short amount of time... oh I don't know, 5 minutes maybe :)

No strip inspections were not required on the Merlin III when using 12lb boost for less than 5min and probably not when used for more, depending on the state of the oil filter upon inspection. Dowding's memo is clear on this.

[Crumpp]

strip inspections were not required after its use:

It means the engine was not required to be stripped apart and internal tolerances checked. That is done at overhaul.

The engine must be inspected according the document you just posted.

It clearly states the engineer must asses the reduction in life of the motor from using emergency boost.

That means done by performing an oil analysis, oil change, compression check, and overall inspection of the condition of the motor.

They might check the crank play as well. All of that only takes a few hours to perform and will tell a mechanic the health of the engine and it requires a reduction in life.

For example, if the compression check ends up with a cylinder not making the correct compression values or the composition/type of the metal in the oil will tell a mechanic if the engine life is nearing its end.

[Seadog]

It means the engine was not required to be stripped apart and internal tolerances checked. That is done at overhaul.

The engine must be inspected according the document you just posted.

It clearly states the engineer must asses the reduction in life of the motor from using emergency boost.

That means done by performing an oil analysis, oil change, compression check, and overall inspection of the condition of the motor.


No, the Merlin engine service manual is pretty clear, that a simple oil filter check was all that was required. Dowding's memo states the same. The engineer officer is always assessing the life of a engine and the regular engine checks are quite sufficient for that.

[TomcatViP]

Well if my car manufacturer would hve include in normal servicing the check of my "Oil filter" as soon as I passed 4000 rpm well... I wld hve run directly to buy a full set of spare engines ;)
What do you think they were looking for ?

[Crumpp]

oil filter check

Seadog,

You have many misguided conceptions about airplanes. Have you ever owned an airplane?

Of course not. You would know this is standard when changing the oil. Every time you change the oil, you cut the filter apart, examine the filter element inside and analyze the oil.

A new engine makes metal and once broken in, an engine makes metal when something is wrong. This metal comes from many different sources in the engine and a mechanic can tell what is going on with your engine from it.

Steel shavings for example generally represents cam wear, valve issues, or ring wear. Aluminum is generally bearing wear. Small flakes of aluminum, depending on the amount is normal or can be excessive. It all depends on the engine type being analyzed.

Chunks of metal are of course very bad.

A sample of the oil is then taken and sent to a lab for microscopic analysis.

Yes, It was a requirement to inspect the engine after each use of emergency power. It was an overload condition for the motor and the reduction in service life had to be assessed by a mechanic and the use of it logged before the aircraft was returned to service.

Combine that with compression checks and an overall inspection will tell a mechanic much about the health of an engine. That is pretty much what is done every year during annual or every 100 hours for commercial/military aircraft to gauge the airworthiness of the aircraft.

Those are the facts based on the documents you posted. Nowhere does the fantasy notion that the Merlin could run in an overloaded condition for as long as necessary exist. It was limited and it was tough on the engine when it was used. The use of Emergency Power had to be logged, the engine inspected, and upon passing that inspection returned to service.

It is that simple, bud.

[Seadog]

Those are the facts based on the documents you posted. Nowhere does the fantasy notion that the Merlin could run in an overloaded condition for as long as necessary exist. It was limited and it was tough on the engine when it was used. The use of Emergency Power had to be logged, the engine inspected, and upon passing that inspection returned to service.


At least you've given up on this fantasy notion of a strip inspection after every use.

In the BofB the average fighter never survived past 100 hours. This is not civil aviation and trying to look at the battle, where the average pilot had a high certainty of death (probably 25 - 40% in RAFFC) as the same as a flying a light aircraft under VFR conditions is ludicrous. No pilot gave a damn about the engine on an aircraft - that aircraft existed solely to destroy the enemy and bring the pilot back safely. RAFFC had lots of spare aircraft and spare engines and pilots had no qualms about expending them at a furious pace: RAFFC lost about 2.5 SE aircraft per pilot fatality.

Pilots could and did run engines at 12lb/3000rpm for a long as they needed to, and in the final analysis, no one really cared, as long as it gave them the edge in combat, which was why the RAF changed over to 100 octane fuel.

A Merlin III will run at 12lb/3000rpm until the fuel runs out. Given a sufficiently large sample size, this will result in a modest increase in in-flight engine failures, but fuel consumption considerations will always be uppermost in the pilot's mind given the low endurance of these aircraft, and this will be the primary limiting factor.

[VO101_Tom]

...
Pilots could and did run engines at 12lb/3000rpm for a long as they needed to, and in the final analysis, no one really cared, as long as it gave them the edge in combat, which was why the RAF changed over to 100 octane fuel...

What does this mean according to you then (copy from other topic)?

*Buzzsaw* linked several links in 109 e3b against spitfire II topic, i noticed one thing:

http://www.ww2aircraft.net/forum/aviation/use-100-octane-fuel-raf-pt-2-a-20108.html

"The discussion was led by 'Glider' Gavin Bailey, who is a well respected historical journal whose material is subject to critical scrutiny by the best of English historians."

He wrote this:
1st August 1940 Memo from Downing re the Handling of the Merlin Engine
This note is advising the pilots that there is an increase in engine failures in the overuse of the emergency 12lb boost.
The interesting thing is that this memo was sent to ALL fighter groups. Had we been talking about the 16 squadrons or less this would not have been the case. It would have been sent to the squadrons involved.

I think, this unambiguous warning. If was used continuously the 12lbs boost, and the engine was ruined continuously, it does not interest, if COD makes the same one.

[Seadog]

What does this mean according to you then (copy from other topic)?

He wrote this:
1st August 1940 Memo from Downing re the Handling of the Merlin Engine
This note is advising the pilots that there is an increase in engine failures in the overuse of the emergency 12lb boost.
The interesting thing is that this memo was sent to ALL fighter groups. Had we been talking about the 16 squadrons or less this would not have been the case. It would have been sent to the squadrons involved.

I think, this unambiguous warning. If was used continuously the 12lbs boost, and the engine was ruined continuously, it does not interest, if COD makes the same one.

If you read Dowding's memo carefully:
http://www.spitfireperformance.com/dowding.pdf
he discusses a number of scenarios that result in engine oil starvation and/or overheating. The engines were failing, not just from overuse of 12lb/3000rpm but from overheating and lack of oil pressure. Steep climbs damage the engine from overheating, not overboosting. Inverted flying damages the engine from lack of lubrication not overboosting. Dowding memo is pretty clear: keep your gauges in the black! Yes, Dowding states not to use 12lb boost for more than 5 minutes, but the real culprit is overheating and lack of oil pressure. No sane pilot, in a combat situation, say with a 109 on his tail is going to worry about using 12lb/3000rpm for more than 5 minutes, and Dowding's memo is nothing more than a reminder to not use overboost except when really needed.

[VO101_Tom]

If you read Dowding's memo carefully:
http://www.spitfireperformance.com/dowding.pdf
he discusses a number of scenarios that result in engine oil starvation and/or overheating. The engines were failing, not just from overuse of 12lb/3000rpm but from overheating and lack of oil pressure. Steep climbs damage the engine from overheating, not overboosting. Inverted flying damages the engine from lack of lubrication not overboosting. Dowding memo is pretty clear: keep your gauges in the black! Yes, Dowding states not to use 12lb boost for more than 5 minutes, but the real culprit is overheating and lack of oil pressure. No sane pilot, in a combat situation, say with a 109 on his tail is going to worry about using 12lb/3000rpm for more than 5 minutes, and Dowding's memo is nothing more than a reminder to not use overboost except when really needed.

I read it, thanks. Sry, this did not convinced me :)
They would write it if the injury of the bearing would depend on the temperature only. "Be watching the thermometer, and untill not in red, u can make what you want". Unnecessarily would limit their pilots (5 min limit) without reason?

"but the real culprit is overheating and lack of oil pressure." - and the strain of the drive. I believe it you recognise it you too, it takes advantage of everything if you squeeze more strength from the drive. Winch, crank, bearing, axis, gaskets, cooling, lubrication. They call it emergency power (notleistung in 109) because of this.

"No sane pilot, in a combat situation, say with a 109 on his tail is going to worry about using 12lb/3000rpm for more than 5 minutes" - totally agree :cool: I would not care about it. But the engine from this probably gets ruined yet. :rolleyes: U reach home, or dont, it depends of luck. If u lucky enough, u can show the oil filter to maintenance team, if not... with an airplane less.

The same one is true for the Bf 109 anyway. Invert flying prohibited its oil system, and the increase manifold pressure until time only it may be used (start und notleistung). It is not linked to the temperature there actually, but this unambiguous. Temperature OR the time a limit defines it, till when it may have been used.

What is interesting yet, and I did not know about the fact that the system of the hydraulic propeller is bound to the engine, not separate system: "loss of engine oil pressure (inverted flight, slow rolls) has an effect on the Rotol aircrew in that baldes return to a fine pitch position". This means that he should lose very much from the performance at this time right?

[Crumpp]

At least you've given up on this fantasy notion of a strip inspection after every use.

A complete fiction that only exists in your mind. Feel free to quote me on the requirement for an overhaul.

You don't read what anyone else writes.

Crumpp says:
Change the oil, oil analysis, filter changes, compression check, and over all inspection for cracks/leaks/function would be in order to ensure engine health.

That is about 3 hours worth of work on a Merlin engine. If they check crank bearing tolerances then you can add about an hour to it. If they find something then of course, it will get fixed or replaced.

Once that is done, the mechanic would enter into the logbook the work performed and return the aircraft to service. A few hours in the shop is certainly worth the pilots peace of mind.

http://forum.1cpublishing.eu/showpost.php?p=295090&postcount=27

[Seadog]

Quote:
Crumpp says:
Change the oil, oil analysis, filter changes, compression check, and over all inspection for cracks/leaks/function would be in order to ensure engine health.

That is about 3 hours worth of work on a Merlin engine. If they check crank bearing tolerances then you can add about an hour to it. If they find something then of course, it will get fixed or replaced.

Once that is done, the mechanic would enter into the logbook the work performed and return the aircraft to service. A few hours in the shop is certainly worth the pilots peace of mind. [/url]

Crumpp says it. The Merlin engine service manual doesn't. The service manual says check the oil filter after emergency boost, so does Dowding. The rest of what Crump writes is his own fantasy based upon the idea that RAFFC operated on the same lines as civil aviation. The reality is that most combat aircraft were destroyed before their hundred hour checks, and 25-40% of RAFFC pilots died before they achieved 100 hours of combat flying. The Merlin engine could be flown continuously at 12lb boost with a low probability of failure and this engine was cycled 100 times from 4.5 to 12lb/3000rpm and the bearings held up just fine:
http://www.wwiiaircraftperformance.org/hurricane/hurricane-12lbs-14nov39.jpg
without the need for repeated engine checks, since by definition the engine was being cycled multiple times per sortie.

[VO101_Tom]

Crumpp says it. The Merlin engine service manual doesn't. The service manual says check the oil filter after emergency boost, so does Dowding. The rest of what Crump writes is his own fantasy based upon the idea that RAFFC operated on the same lines as civil aviation. The reality is that most combat aircraft were destroyed before their hundred hour checks, and 25-40% of RAFFC pilots died before they achieved 100 hours of combat flying. The Merlin engine could be flown continuously at 12lb boost with a low probability of failure and this engine was cycled 100 times from 4.5 to 12lb/3000rpm and the bearings held up just fine:
http://www.wwiiaircraftperformance.org/hurricane/hurricane-12lbs-14nov39.jpg
without the need for repeated engine checks, since by definition the engine was being cycled multiple times per sortie.

I agree, huge difference is between 5 min and 8 hour, but the engine failure IS exists. If 20% of flight time using 12lbs boost, the engine gets damege certainly. After 50 hour test, this Hurri have cylinder head cooling leak. But you don't know, after how much time got damage. Maybe after 5 minutes, maybe one hour, maybe eight. Maybe its far from 5 min, but also far from "continously without damage". We do not say that the engine has to explode after 5:01 minute. But the problem exists, and it is not possible to leave it out of consideration.

I believe it if you say that a limitation was official onto the machine, but nobody took it seriously. Okay. But this does not mean that it did not have consequences. If you don't want to, you do not deal with it in the game. But let it have consequences. As it is for the other side.

[VO101_Tom]

Yeah I forgot this :cool: According to you, what was the purpose that the oil filter was taken out (without an oil change)? What did they make with it? It was thrown in into a big green box, on which was a huge "not interest " stencil? :grin:

[Seadog]

I After 50 hour test, this Hurri have cylinder head cooling leak. But you don't know, after how much time got damage. .

The early Merlin engines were prone to cylinder head leaks, as per the memo, and this had little or nothing to do with 12lb boost. WW2 combat engines had a short service life, by civil aviation standards, and, as I have pointed out most aircraft and engines never survived past 100 hours.



Yeah I forgot this According to you, what was the purpose that the oil filter was taken out (without an oil change)? What did they make with it? It was thrown in into a big green box, on which was a huge "not interest " stencil?

They would examine the filter for evidence of metal filings which typically indicated bearing damage. No metal = no need for further investigation. Obviuosly the engine flown for 49.5 hours with repeated cycling of 12 and 4.5lb boost never showed evidence of bearing damage, or they would have stopped the trial.

[TomcatViP]

The early Merlin engines were prone to cylinder head leaks, as per the memo, and this had little or nothing to do with 12lb boost. WW2 combat engines had a short service life, by civil aviation standards, and, as I have pointed out most aircraft and engines never survived past 100 hours.




They would examine the filter for evidence of metal filings which typically indicated bearing damage. No metal = no need for further investigation. Obviuosly the engine flown for 49.5 hours with repeated cycling of 12 and 4.5lb boost never showed evidence of bearing damage, or they would have stopped the trial.

Man engine and airplane are strategical assets in a war. Not so much men ;) This why you've got disciplinary council and your superior makes good or bad report on your behavior. This was not paparazzi on look. Think that the logistical bckgrd to sustain a full air-force at war was simply enormous. You don't want to change an eng because some fighter jock only wanted to buzz Lili's home.

May I remind you the late war LW with thousands of a/c build each month but with only hundreds on the fronts?

Even in the late war Tempy the Emergency power had a restricting safety link.

The Spitfire during BoB was a wonderful aircraft, potent, powerful and survivable. That's it.

[Blackdog_kt]

Crumpp says it. The Merlin engine service manual doesn't. The service manual says check the oil filter after emergency boost, so does Dowding. The rest of what Crump writes is his own fantasy based upon the idea that RAFFC operated on the same lines as civil aviation. The reality is that most combat aircraft were destroyed before their hundred hour checks, and 25-40% of RAFFC pilots died before they achieved 100 hours of combat flying. The Merlin engine could be flown continuously at 12lb boost with a low probability of failure and this engine was cycled 100 times from 4.5 to 12lb/3000rpm and the bearings held up just fine:
http://www.wwiiaircraftperformance.org/hurricane/hurricane-12lbs-14nov39.jpg
without the need for repeated engine checks, since by definition the engine was being cycled multiple times per sortie.


Sorry, but the fact that you claim continuous running on what's called emergency power and then try to support it with the argument that most planes would be destroyed pretty fast anyway, makes it all sound like an effort to disguise the fact that if the aircraft survived long enough they would get a higher proportion of engine failures.

It would be more accurate to phrase this a bit differently: engine failures were rare not because WEP was free of charge, but because the aircraft rarely survived long enough for the engine abuse to take effect.

Like i said before, they wouldn't call it emergency power if it was fine to use it all day long and fuel burn was the only real drawback. They would just call it full power and insert a footnote "warning, it burns fuel really fast".

Emergency has a pretty strong connotation to it, it means "don't use unless you're about to die" in simple terms.

And finally, this is not a thread about what the Merlin could or couldn't do. This is a thread about modeling engine limitations on ANY kind of engine in the sim if it also had them in reality. If the Merlin did or didn't have such restrictions is a completely different matter and totally out of the scope of this thread. What are doing here is this:
"Supposing engine X has limitation Y, what's the best way to have this reflected in the sim?"

Why do you feel the need to constantly hijack this thread in the direction of the Merlin specifically is completely beyond me, especially when you can just as easily start your own thread and argue your point there without dragging this one completely off-topic.

We are not discussing the capabilities of a specific engine here, we are discussing a proposed idea for a game feature. If you want the Merlin to be exempt from it, feel free to start a separate thread about it or use one of the many already provided. We don't need every single thread around here to revolve around the Merlin and the use of 100 octane fuel, there's several of them already ;)

Excuse me the bolded text, i mean no hostility and it's purely for emphasis. It's just getting mighty tiresome trying to discuss an interesting idea with some like-minded fellows in the pub and having someone from across the bar constantly jump in the middle of your group shouting "AHA" as he dumps a load of old musty dossiers and charts on the table before he starts on something that has almost nothing to do with the discussion at hand. Don't drive us out of the pub man, especially when there are people having the kind of discussion you prefer just two tables over :-P

[Seadog]

And finally, this is not a thread about what the Merlin could or couldn't do. This is a thread about modeling engine limitations on ANY kind of engine in the sim if it also had them in reality. If the Merlin did or didn't have such restrictions is a completely different matter and totally out of the scope of this thread. What are doing here is this:
"Supposing engine X has limitation Y, what's the best way to have this reflected in the sim?"

Why do you feel the need...

We are not discussing the capabilities of a specific engine here, ;)

Excuse me the bolded text,

b) establishing an engine's limitations is a prior requirement before you can sim it. There must be others who can comment on the DB engine's reliability and reliability with WEP. Until these limits are discussed, how can you create a sim based upon RL?

I am not hijacking the thread, when I discuss engine limitations, or the mathematics and probabilities of engine failure versus average service life: These are the essential factors that have to be modelled but if engine life with repeated overboost works out to be greater than the average life of an aircraft, then the use of overboost is probably extending the average life, rather than shortening it.

b2: Indeed not, but no one is presenting info on Luftwaffe engines. I wish they would.

I suspect that those familiar with the Me109 for example, are well aware that the use of a properly modelled WEP while flying over London, will probably mean a long swim somewhere in the English Channel, and thus fuel considerations are probably a primary factor in limiting the use of 1.3/1.4 ATA in the 109, while flying over Britain, and while this is less a worry for RAF pilots it is still very much a factor when fuel consumption rises to ~105gph for the Merlin III at 12lb/3000rpm.


It would be more accurate to phrase this a bit differently: engine failures were rare not because WEP was free of charge, but because the aircraft rarely survived long enough for the engine abuse to take effect.

OK. Now how to sim that?

[Seadog]

http://i38.photobucket.com/albums/e133/Kurfurst/BoB%20Stuff/shacklady100octane_2.jpg

OK so here we have the engine life of a Merlin III at 12lb boost and in 1938 it was 10 hours and later engines it was 20 hours at 12lb boost.

20 hrs = 30 sorties flown exclusively at 12lb/3000rpm, or 80 sorties at 15min/sortie, which is already exceeding average aircraft life during the BofB.

[Crumpp]

OK so here we have the engine life of a Merlin III at 12lb boost and in 1938 it was 10 hours and later engines it was 20 hours at 12lb boost.

Geez....:grin:

Nowhere except in your mind can you run a Merlin at 12lb for 10 hours.

That is the total time the engine ran during endurance trials of 5 minute intervals with a 20 minute rest period between each interval.

It could be used for 5 minutes at a time. That use had to be logged and the engine inspected for serviceability, and the reduction in life assessed before it could flown again.

[Seadog]

"I had to return from Nuremburg in a Wellington II on one engine and used maximum boost and revs on a Merlin X for five hours with no sign of distress..." = +10lbs at 3000rpm.
The Merlin in Perspective,p25.

[TomcatViP]

Merlin X (two stage - two speed s/c) later eng model (with 1145 HP and 9lb ;))

[Kurfürst]

Merlin X (two stage - two speed s/c) later eng model (with 1145 HP and 9lb ;))

In 1938 it was probably an early internal RR - and not a service - designation (X = eXperimental?) for a Merlin with 100 octane IMHO.

[TomcatViP]

X stand for 10 :rolleyes:- Beware that all those long night of typing might hve put some excessive strain on your brain eng ;)

[Blackdog_kt]

OK. Now how to sim that?

A few people already gave pretty good ideas on that, but it's currently buried under the Merlin debates :-P

As a short recap:

a) accelerated engine wear model if spawning with a brand new airframe on each sortie, selectable by the player from the difficulty options

b) realistic engine wear model if spawning with the same airframe (relevant aircraft parameters carry over from one sortie to the next in the context of a dynamic campaign), along with a penalty for deliberately "recycling" airframes with abused engines, both for single and multiplayer...once again, selectable from the difficulty options

c) the two above models are mutually exclusive...we shouldn't be able to enable both an accelerated engine wear model and a "carry over" model, clicking one on the difficulty options would deselect the other, but it would still be possible to disable both

This makes sure that if the player is so inclined, he can fly with the uncertainty and chance of mechanical failure that engine abuse would pose.

Simple, clean, optional ;)

[TomcatViP]

A few people already gave pretty good ideas on that, but it's currently buried under the Merlin debates :-P

As a short recap:

a) accelerated engine wear model if spawning with a brand new airframe on each sortie, selectable by the player from the difficulty options



An accelerated wear model wld be very difficult to achieve in term of stability. Mind that any programming glitch or non-anticipated player action would hve its repercussion magnified by the accelerated engine code.
I guess that 1C will need a lot of trying in here that way.

[Crumpp]

"I had to return from Nuremburg in a Wellington II on one engine and used maximum boost and revs on a Merlin X for five hours with no sign of distress..."

As a RL pilot, I see that as maximum continuous which is THE engines maximum boost and revs....

He does not say he used "Emergency Power"....

[csThor]

b) realistic engine wear model if spawning with the same airframe (relevant aircraft parameters carry over from one sortie to the next in the context of a dynamic campaign), along with a penalty for deliberately "recycling" airframes with abused engines, both for single and multiplayer...once again, selectable from the difficulty options


Well ... for a campaign (or an online campaign for that matter) we'd need to use the Werknummer/Serial Number to track airframes. Meaning the unit the player flies with has a pool of airframes (according to historical values). Each pilot would be assigned one aircraft and the campaign engine would have to track not only engine parameters but also combat damage or accidents. Then we enter real-life inspection cycles and repairs so that it may happen the player gets another aircraft for a mission while his own crate is being serviced/repaired.

[TomcatViP]

Seems great.

Would you add fleet management at squadron level for online campaign ? I bet you'd get a large success that way ;)

[csThor]

For the Luftwaffe this would be wrong. Here the Gruppe is the entity that does the "accounting" and one Officer is especially there to oversee the technical aspects of the aircraft (called the "Technische Offizier"). He and the Oberwerkmeister (Chief Mechanic) of a Staffel would be responsible for the technical "well-being" of the unit. ;)

[Blackdog_kt]

Well ... for a campaign (or an online campaign for that matter) we'd need to use the Werknummer/Serial Number to track airframes. Meaning the unit the player flies with has a pool of airframes (according to historical values). Each pilot would be assigned one aircraft and the campaign engine would have to track not only engine parameters but also combat damage or accidents. Then we enter real-life inspection cycles and repairs so that it may happen the player gets another aircraft for a mission while his own crate is being serviced/repaired.

Initially i would just have "no-name" airframes that just suffer wear and tear through missions to make things simpler to implement and test.

However yes, what you describe would be the end goal in terms of this feature and how it would/should be implemented ;)

As for squadron/fleet management some people like it and some don't, so i would advocate it being optional. The campaign engine would do it automatically if the player wouldn't interfere, but it should be possible for example to go into the squadron's dossiers and assign your best wingmen some healthy airframes.

This is similar to European Air War, it just expands the same idea into more features, where you were presented with a computer generated sortie roster before each mission but were still able to change who would fly if you wanted to.

In short, the PC would take care of all the "accounting" if i didn't do anything, but i would still be able to change things around if i wanted to without having to stick with a full time job of squadron logistics on every single mission.

This enables those who like it to go all out on it, those who don't to just leave it to the PC and the rest to simply change a couple of things and leave everything else to the PC.

[335th_GRAthos]

That gets a bit too far into "Historical accuracy!" Most of us paid for a flight sim, not an accounting sim!


+1 :D

This reminds me of the "Analysis - Paralysis" saying...

I am afraid that, if some people do not look at the whole thing from a more practical point of view, CoD will become a great historically correct simulation which nobody will want to play, much less buy :(


my 2cents

[Al Schlageter]

Geez, they can't even get the game to function properly as it now and people want more complication added.:rolleyes:

[TomcatViP]

Geez, they can't even get the game to function properly as it now and people want more complication added.:rolleyes:

Well are u talking of a bunch of late operated Spitfire with 100octane fuels being fully modeled according to some's fantasy dreams ? :cool:

[Al Schlageter]

Well are u talking of a bunch of late operated Spitfire with 100octane fuels being fully modeled according to some's fantasy dreams ? :cool:

UGH? What are you babbling on about?

[Blackdog_kt]

Geez, they can't even get the game to function properly as it now and people want more complication added.:rolleyes:

This complication you speak of is something that i would probably be working on myself if i knew my way around c# and dissecting the available dll files and commands.

It's like coding a DCG style environment straight into the sim's interface, or have it run on your personal server with a custom interface. This is doable in the sim not in the future but right now, which is very impressive to me. We just don't have enough people yet who are well versed in coding to come up with things like that.

What i'm trying to say is, this is something that could be done independently of the developers because it's a separate layer: if it was a 3rd party project it would neither delay bug-fixing on the developers' part nor get their hands fuller than they already are ;)

[king1hw]

In the push for what everyone here considers there side of Historical accuracy (I prefer the pilots side more then the engineers side because they were there) the main problem I see is to neuter the RAF planes, to give some aid in a combat situation for a 109 pilots so that our engine in damaged after 5 minutes (Increase that to 20 and I will support you). I saw this with il2 1946. No body wanted to put on there server the 25lb spit because it was to good and now in CoD we cant use the spit MKIIa on anyones server. So I try to fly within the manuals requirements, however the fact that has been stated is that the wear was not as prevalent but was there. The manual gives the recommended 5 mins, but in many pilots logs they went over this often in giving chase in dogfights.

Here is another suggestion and this should be up to the server side. ENGINE LIMITS or NO ENGINE LIMITS.

Then it is not one belief force on the game when I have seen data from both sides in this argument and see that a strong contingent from the Axis flyers again trying IMHO to neuter the allied planes.

I have flown online now for 3 weeks and have been killed by really good 109 pilots from 46 ( who I recognize there call sign) and I have flown in and out of boost cut in those occasions. I got bested by a better pilot not whether I had proper engine management which would only force me to enter it into my pilots log then you say the plane would be overhauled well I will just jump into a new bird and go again(gotta love Refly). One thing that could help that is rearm and refuel option on landing try to keep one plane on going.

Anyway my 2 cents.

[Blackdog_kt]

Actually this proposed feature has nothing to with crippling the RAF aircraft, because
a) it would apply to all aircraft and
b) it would be user-selectable...don't like it, don't use it (or fly on another server)

What i'm trying to say is, the topic of this post is how could we possibly simulate manufacturing tolerances and airframe wear and tear in the future, not some kind of a conspiracy theory.

I could just as easily embark on a detailed explanation about how the simplified engine management of IL2:1946 tended to favor the aircraft with the bigger/more powerful engines or in some cases completely reversed the workload advantage/disadvantage to the opposite of what it was historically but i have no interest in derailing this thread just to get in an argument, i like the proposed feature and i'd like to do my part to keep the thread relevant.

I think a lot of the resistance displayed in such topics is people fearing their preferred gameplay style will be rendered obsolete and the pool of like-minded players to fly with will decrease due to many others moving on to a more refined and complex style, so they try to limit the potential of such new ideas taking root. In all honesty however, we can't expect to hold back everyone who prefers a different playstyle, otherwise we'd all be forced to fly on no-cockpit servers in order not to upset the more arcade-minded players: it's impossible to achieve plain and simple, people will fly and play the way they want to play.

Since this is supposed to be a simulation game, a large enough amount of people will gravitate towards increased complexity if it's provided and if we have the proper interface to use it. As long as such changes are not forced on everyone else and are user-selectable, i'm not just ok with it it but i eagerly anticipate it as well.

As long as people can turn off the features they don't like, there's no justification to limit these features (provided they can be reasonably implemented) and deprive another part of the community of their enjoyment.

[king1hw]

In multi-player mode I think it is not a good Idea and to go and neuter all planes is stupid. I for one am all about historical accuracy and not to have a 109 e4 and 12lb spit and hurricane is also stupid. Does that mean that all fighters allied and axis should have access to better fuel ratings YES.

So this bickering back and forth on what the game should have how about the team focus on the MP sound issue and make it better. To argue this when the game is having so many problems online is STUPID. I for one do not agree with and have never agreed with Kurfhurst(Docs all dated Dec. 1939) There is no logic behind the air marshal not allowing 100octane at all fighter bases is ludicrous and to not allow them to take the merlins to 12lbs is just does not make sense maybe that's why the allied won the war lol thank god.

To get the game correct adding damage to engine after 20 minutes engaged boost for all aircrafts would take care of the non flyer. I said 20 because it is documented in pilots notes of them running longer. The damage could effect a rearm and repair mode if we had it in the game to force pilots not to refly like junkies. Again make it server side and those that want to fly historical sim will flock to those servers.

[Kurfürst]

Oh look, I guess some poor thing got a ticket to the BANamas..! :D

[TomcatViP]

I saw this with il2 1946. No body wanted to put on there server the 25lb spit because it was to good and now in CoD we cant use the spit MKIIa on anyones server

The day I made my mind on the "Spit" 25lb was when I was trying to shake that nasty thing climbing at 500kph indicated speed from deck to 5K on a 262.... That thing was actually slowly gaining on me !

You can say what you want but still can't call a Spit what is not a spit. You might one day understand why nobody wanted to see it in game .. same thing for what you call today an MkIIa :evil: