Oleg, SOW engine abuse by pilot?
 

I'm starting this thread since I cannot find any topics with the appropriate subject.

I wonder how engine damage in SOW will be modeled. the IL2 series are lacking here, there hardly is any penalty for exceeding the manifold pressure, apart from overheating.

For example, if we are flying below the critical altitude of the first supercharger stage and switch to the next, we don't throttle back. The extra drag the next stage produces is modeled correctly since engine RPM drops. But the manifold pressure goes up to a maximum, say 60 inches in the F4U, which is already more than the 53 inches allowed for military power. In real life the pilots throttled back, engaged the next supercharger stage, and throttled up to the maximum allowed manifold pressure if he wanted military power. This had to be done to prevent engine damage due to engine knock/detonation/pre-ignition of the fuel/air mix in the cylinder, which can lead to catastrofic damage.

I'm making a few references to my posts in the other topic:

http://forum.1cpublishing.eu/showpos...postcount=1591

http://forum.1cpublishing.eu/showpos...postcount=1593

http://forum.1cpublishing.eu/showpos...postcount=1595

And a post by someone else:

http://forum.1cpublishing.eu/showpos...3&postcount=21

More information on this subject:

http://en.wikipedia.org/wiki/Engine_knocking

Thank you for your time.

Interesting reading, more in-depth information on detonation, although it is focused primarily on non-supercharged aviation engines. It shows again the element of heavy knocking or pre-ignition is a severe danger.


These graphs show a non-supercharged engine operating at sea level. At higher manifold pressures, damage will happen much sooner.

http://www.avweb.com/newspics/pp43_d..._medium_lg.jpg

http://www.avweb.com/newspics/pp43_d...n_heavy_lg.jpg


http://www.avweb.com/news/pelican/182132-1.html

I'm pretty happy I drive a turbocharged Diesel :)

Its my understanding that the new damage model is going to be much more complex...

And from what I remember, damage modeled within a specific mechanical system will have consequences (triggers maybe) that will effect "other" mechanical systems within the aeroplane (I think I remember reading something about this in a "Q&A" with Oleg)...

I think that Oleg is going to save the specific features of the new damage model for the game release...but I would love to be proven wrong. ;)


p.s. Nice reading Azimech, thanks.

Yeah, I remeber some talk about stuff like damage modelling. Oleg mentioned in an interview that all systems can get damaged and some areas which are linked to others will have a domino effect.

For example hydraulic pressure, too low on that and your gear won't drop. :grin:

I never get a warning about hydraulics in IL2 1946, but often my gear won't lower due to battle damage.

Or the hydromatic propellor governor goes to fine pitch, again due to battle damage. In real life, this can also happen when metallic particles in the oil clog hydraulic lines or components.

Yeah, I've wanted to see more complex engine management in Il2 for a while and I hope it comes in SoW. One of the damage features I do like in Il2 is the runaway prop governor, but I wish the routine of starting the aircraft, and slamming the engine to full rev's and taking off would be changed.

How awesome wouldn't it be if you had to prime, see your mechanic run the inertia for you and basically do all the stuff you'd need to do to even get it started......*drools*

Priming is cool but having a man standing on the wing of your 109 or Dora cranking like hell would be a lot of work... I'd settle for an electric-inertia starter.

Something that is not included in the series is the http://en.wikipedia.org/wiki/Coffman_starter

http://www.youtube.com/watch?v=S1rc3AmX0XQ

http://www.youtube.com/watch?v=IACjOvyx5hs

:mrgreen:

Don't get too excited about the Bits-n-Pieces.
If you've been around long enough, you'll remember Oleg giving the exact reasons why he did not put the whole engine startup stuff into IL2.

If he puts this into SOW I'll be surprised, but if you want that stuff, there are other sims that have it.
:)

quite. i gather SoW is meant as more of a combat flight sim, than a procedural one.

Yep, remember that post. The DCS:Blackshark and upcoming DCS:A-10 is a good alternative but they lack in teh graphics department IMO. That's why I'd love to see it in a good looking game like SoW is going to be. And those aren't warbird sims. *sigh*

S!

I recall Oleg mentioned a clickable cockpit in a post not too long ago so that could indicate we get procedures. But I would guess this feature is tied to difficulty settings, that at lower settings it works like in IL-2 by pressing a single button engine starts etc. For me having to start up the engine and warm it etc. is part of the immersion and a way to emulate what these lads did back then. But tastes are different..

One should not forget that those "procedures" have a great influence in the air combat!!!!
If one doesn't follow the procedures in i.e. the engine handling one will pay for it big time in power loss!
What is a spit or a 109 with 500hp? right, a sitting duck waiting to be shot at.
The engine start up is a procedure that always is the same, with very minor modifications.
There is no reason not to put it on 1 key and the switches and handles are moved automatically, but manually one should be just a bit faster doing it :-D
Also the procedures in the stuka for the dive attack, cooler closed (engine stays warm!), prop pitch to "feather"(no over rpm), trim to neutral (straight dive), "Hoehenlader" to "Bodenlader" (no manifold overpressure), release altitude set, dive brakes out.
Just one thing missed and one won't be on target or gets problems getting away.

On closing the cooler when diving the Stuka, nowadays "shock cooling" is proven to be a myth. I don't say the procedure when diving shouldn't be included, I just hope it won't affect the engine.

And however I like the concept of clickable cockpits and startup procedures, it is a departure from the original topic.

What are the thoughts of you guys? Should exceeding maximum manifold pressure lead to engine damage or not? I think I know the answer already.

Besides, there are elements in startup procedure that aren't necessary. Checking magneto's for one, is done to check both the ignition systems. During flight, there is no reason to switch off one of the systems. What would happen if you start a mission, you check the mags only to find out one of them is failing? You'd cancel the mission and restart. It might enhance immersion but it won't prevent the engine from starting, there totally is no skill required. It's the same like attaching the relief tube to your private part.

That was on the check-six interview. It was confirmed that everything was modelled, from start-up sequences to turning on the de-icers when climbing through clouds in order to clear the canopy of the mist.

Plus,

Robtek is right on the money here. Why do you think that most of the pilots who got shot down and survived to talk about it shared a common phrase among them? "I didn't even see him coming".
Because these birds are not supposed to be easy to fly, "turn the nose around and have at it" affairs, which requires people to keep their heads in the cockpit for extended periods of time, even taking quick looks at the instruments during combat. If this wasn't the case then aircraft designers wouldn't bother inventing the head up display as it would not be needed, but history and practical application suggest otherwise.

Bottom line is that up to now, we've been having it way too easy in combat simulators that focus on prop-driven warbirds. This is neither realistic nor conducive to extra gameplay possibilities, as it takes out a huge chunk of tactical considerations and decision making process from combat. It is also not easy to model, because in many cases we lack the interface to do it properly. We either have to use the entire keyboard plus a HOTAS with profiler software (more realistic but more expensive too), or resort to using the mouse and clicking on things (a bit clunky at times but as cheap as the price of your mouse).

Of course, some people might want it easy and that's their choice on how they want to fly the sim. No worries at all, use the difficulty settings and tone it down a notch, fly in the appropriate relaxed difficulty servers and everyone is happy ;)

As for the topic at hand, i agree that exceeding manifold pressure limits (or specified time limits during which over-boosting is briefly allowed,eg WEP) should damage the engine. Maybe not outright seizing it, but resulting in a more subtle and gradual degradation of performance which, if left unattended, would result in the engine seizing, starting a fire or blowing a cylinder or two. Also, using high MP with low RPM should result in damage from exceeding the torque limits as well.

AFAIR magnetos are modelled in IL2.. I vaguely remember fiddling with them sometime ago.

Ahem.. there's no skill in procedural startups and checks - one tends to naturally do this 'at speed' in IL2 anyway - skill in emergency procedures, yes!.

And of course, 99.999999% of us have keyboard CPits which limits proper pit realities. Things like fuel pumps, and changing tanks and their effects would add a nice touch.

That's exactly why we're advocating it. For example, a lot of the smaller aircraft back then had separate fuel feed mechanisms, if you forgot to periodically change from one tank to the next you would find yourself with a seriously unbalanced aircraft.

The thing is the procedures are not the main goal here, the aim is to have the mechanical intricacies and inner workings of an aircraft properly modelled. Procedures come in handy only because they are a means of making sure you don't forget important things. I don't care about having to follow a checklist to the letter, but i do care about the lack of consequences when we abuse our aircraft because that detracts from fidelity. Simply pressing "I", slamming the throttle forward and keeping it there for the duration of the mission just doesn't do it for a lot of people anymore.

perhaps a slight exageration:-P
there's more pit builders than you think(imho)
http://forums.ubi.com/eve/forums/a/t...5/m/5271012437

Yes, magneto's are modeled in the IL2 series but setting magneto's is good for nothing. Running with both mags produces a dual flamefront in the combustion chamber which reduces the risk of engine knock, very important in the big bore engines of WW2, so switching them has no purpose at all.
Not even for shutting down the engine like we do with our car, in aircraft we let the engine running above 1000 rpm or more, en set mixture to Idle/Cutoff.

Selecting fuel tanks has a real function and should be there. Not only balance is a factor, battle damage too if a tank is damaged beyond the self-sealing capacity. Plus, every tank has a feed and a return line. The return line is for fuel that has not been used by the engine. Such a waste if that bleeds into a shredded tank.

Same as booster pumps. If the mechanical fuel pump on the engine fails (battle damage?), most if not all planes have electrical pumps that can be enabled. You have a sudden drop or total loss in power, you check the fuel pressure gauge, see that it's low or gone, and switch on a backup. That's immersive.

Damage to the cooling system: If a plane has radiators in/under the wing or fuselage which are damaged, you close them to prevent loss of all cooling fluid and adjust power for the loss of the cooling capacity.

Something else that can be considered: generator failure. You check the ammeter and see it's showing zero so you're running on battery power only. So decide quickly: withdraw from combat and try to get to base, and/or switch off all electrical systems you don't need so the ones you really need will work longer. That could mean switching off your flight instruments, lights, trimming, guns, revi, radio's/navigation... maybe even the hydraulic pump if it's electric and there is a pressurized buffer in the system. You check the voltmeter. The more systems are online, the lower the voltmeter will show, and the faster it will drop. Electrical motors will turn slower but they will work. On the other hand delicate equipment like navigation or radio's, which use a lot of power, drop dead below a certain value. You switch some systems off and see the voltmeter rising.
Since you have no idea without instruments what the temperature of the engine will be: open cowl, intercooler and oilcooler flaps to the max, switch to lower supercharger stage or lower turbocharger RPM.

Especially the FW190 has all primary flight controls operated electrically, even flaps and undercarriage. And also the Kommandogerät, which operates hydraulically, mechanically and electrically. With the generator gone, the voltage already drops and response to input by the pilot will be slower and the motors may even have trouble fighting the effect of compressibility. If the battery is almost empty, landing gear and flaps might not lower correctly, and using more motors at the same time, for instance using all control surfaces at once, might stall one or all motors.

What's even worse is that a battery, using a chemical process, loses a lot of it's capacity at low temperatures. So if you lose the generator and are at high altitude, descend before your battery cools down and you lose even more power.

Brilliant post Azimech. Just goes to show how much enhanced systems modelling would open up new tactical possibilities and situations.

Another one, consider the effects of hypoxia with a damaged oxygen delivery system, as well as the risk of fire because of leaking oxygen. If your aircraft doesn't suffer some kind of immediate fire or explosion (in the event that the pressurized tank suffers a direct hit by a cannon shell or an incendiary round), you would still be limited to 10000-12000 feet or thereabouts for the remainder of the mission.

As for magnetos, the main reason to switch between them is not to run on a single one but to determine if one of the two has failed. Initially dual magnetos were provided as a means of redundacy/safety, but then it was discovered that the engine works better with both of them on just like you pointed out.

It then became standard practice to run the engine on both, unless a failure of one system forced the pilot to switch to the other. The way the magneto check works is that when running on both the engine runs at a slightly higher RPM than when running on one. Usually, the drop in RPM is miniscule (50-100 in many cases) but it still registers on the instrument needles.

Knowing the correct drop, it's easy to cross check and see it it's "by the numbers" supplied by the manufacturer or not. In fact, pilot operating handbooks usually state permissible values as "a drop of no more than X RPM when switching from both to a single magneto AND no more than Z RPM difference when comparing left and right magnetos". In this way, if the RPM drops more than X RPM when running on the left magneto, and/or running on the left magneto is more than Z RPM lower than when running on the right one, it's easy to see that the left magneto is faulty.

Well, thank you :)

Which also would be affecting a crew.

Yes, all true. I wouldn't mind if it's in the sim but it could be left out, since checking the mags & engine RPM is only done on the airfield prior to a mission or any flight. If one of the ignition systems fail due to battle damage, there would be no reason to test during flight whether it's the first or second. Well maybe if you don't know one has failed but have a hunch and wish to lower manifold pressure to prevent engine knock.

Offtopic:
On fire and explosions, I wonder if SOW will have the properties of Elektron modeled as used in some aircraft types of the Luftwaffe and used for their incendiary bombs and cannons, also during the BOB. You know the stuff, once ignited it would burn a plane in half with bright white flames.

From the Heinkel He 70 wiki:
"The main weakness of the He 70 design soon became obvious. The He 70 airframe was made out of so-called "electron metal", a very light, yet strong alloy of magnesium, which burns spontaneously in air when heated, and is only exhausted when covered in sand. A single hit from a light machine gun usually set the entire plane ablaze, killing the crew. "

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

http://www.ww2incolor.com/forum/show...neguns./page10

I think you will find that the FW190 "primary controls" ( Elevator, Ailerons, Rudder) are actuated by conventional push rods.

The Elevator Trim, flaps and undercarrage ( classed as a "secondary controls") were however electrically actuated. Rudder and Aileron trim were only adjustable on the ground.

Cheers!

I stand corrected :)

ok so this debate about realism vs. playability... should actually be more on the lines of... a counter-strike type first person shooter (but in the sky), or a simulator.

trying to be as close to real life as u can get while sitting in your computer chair... the debate weather its redundant or quicker or useless doesn't matter, the fact of the matter is... super high manifold pressure killing ur engine in a few seconds is realistic, so it should happen... if u don't follow procedures and dont managing your engine properly you should be punished for it... if those kinds of things don't happen, it can't really be considered a simulation nowadays, can it?

so for all you "one button does all" dudes, sorry i couldn't find a flying game like that, but i found one thats "two buttons do all"

right here

What a great game! I love it!

It really brings me back in Commodore 64 mode!

Screw SOW, I'm gonna play this the rest of my days!

My highscore after two runs: 11681

XD

I too like to have as much realism as possible, but there's no need to think ill of the preferred gameplay experience of others.

In fact the best scenario would be super high realism for the old timers, but with a lot of difficulty options for the people who want it easy, so that we can bring more people into flight sims. Better yet would be the option of not just turning off realistic features, but have help tools that assist the user in managing them. This way the realistic features are still working, but at the same time the software itself shows you how to do it and helps you learn it. It's a bit better than going from no torque and simplified engine management straight to full FM options and realistic systems modelling, as it smoothens out the learning curve.

It's not in our best interest as a community and a hobby to pose as the "smart guys" who know it all and drive away any potential newcomers. What's in our best interest is to have our gaming software be highly realistic and challenging, but also highly accessible and scalable, so that newcomers can come in, enjoy themselves and learn as they go in stages, without quitting because of a steep learning curve and frustration.

I have a lot of friends who are interested in WWII and i'm trying to tide them over to flight sims. You know what they tell me? "It's too hard to just jump right in, plus it takes lots of time to learn and make the experience worthwhile". If these people could be assured a smoother learning curve, i alone could help make an extra 3-4 sales for SoW and possibly for future flight sims, and that's people who have never ever used a flight sim in their lives.

So yes, let's have it as ultra-realistic as it gets, but also have enough help options that will help us win over new blood ;)

Exactly.

No, they just dont really really care, and you cant make them learn.
Being interested in WW2 and being willing to learn how to fly are two different things.
We are nerds, and no no, we cannot pull 'em over to the dark side.
It's a fact, live with it.

This passion arises with the age of ~10 - if not, it never will.

Well, Swiss, thanks for giving me such a valuable and accomodating insight into the minds of my real-life friends, whom by chance you don't happen to know. Are you a psychic? What are the lottery numbers? :-P
Maybe i didn't properly explain what i mean, so here it goes again.

For the people i refer to, it mostly boils down to "that's so cool, but i don't have the time and inclination to study all this between work and other real life commitments". If difficulty options scale well enough to make them feel that they are playing a game instead of studying flight theory when they come home tired from work, they'll have a much better chance of picking it up. Cheers ;)

Sure, but IMO the vast majority of such people won't stick around to pick up the harder bits beyond the easiest mode.

I think Blackdog's (and several others) point is that it doesn't really matter how each individual prefers to play the game, so long as they buy it and enjoy it enough to tell their friends about it thereby subsidizing the development of the game that we want to play.

I'm all for as much realism as possible, but I just don't see how making the difficulty scalable hurts anyone, anyone at all.

Or am I responding to the wrong argument? These things can get quite hard to follow.

That's exactly my point BadAim. I don't care if my friends never fly full real. As long they enjoy the game enough to buy it and fly it at their preferred difficulty settings, they help fund the next expansions for us ;)

It is not as simple as "let everyone select the difficulty they want".


1.
There is a portion of the market that wants to be able to boast about "beating a game on the hardest settings" without actually putting too much effort in. It's considerations like that that which has led to the "dumbing down" of quite a few games.

Examples include Gothic III where a very well thought out combat system in Gothic II and Gothic I was replaced with US style "stand next to the monster and mouse click as fast as possible", the more recent versions of the Warhammer tabletop game franchise and of course the classic dumbing down of D&D in the recent 4th edition.


2.
The issue arises of how many people will use a feature versus the work involved implementing it.

If for example the work involved in realistically simulating the effect tire pressures have on takeoff means losing an entire extra aircraft and only a handful of users will ever check those tire pressures before takeoff, the feature is best left off, at least initially.




PERSONALLY I am interested in as much "realism" and "immersion" as possible and for example in Il2_1946 fly with cockpit on and LHS speed-bar and RHS HUD turned off :D However there is a limit to what can be implemented in a mass marketed game.

Good points Galway. In fact, i suspect there's quite a portion inside the sim community who also subscribe to the mentality you laid out in your first point.

A few months back some of us started asking if it's possible to implement certain features, some of which have been confirmed by the check six interview as being entirely possible under the new engine.

What happened was that an interfacing issue (clickable cockpits being unrealistic and clunky) was used as a red herring to throw the discussion off from the important issue...that some people who are content to fly full switch in IL2 and wish to keep flying that way, would lose the full switch "boasting rights" if SoW came with more options to tick that would make it more difficult.

In fact, the debate only died down completely when the check six interview was aired and such features were described as being already in the engine.

hehehe... boasting rights for full switch. That's a funny thought!

Well, it's called boasting only by those who don't take on the challenge :-D

I'm sorry mate but "we" who? You really switch off your propeller plane by cutting the mixture? That is one helluva dangerous game man.. If I did something like this with my instructor would have kicked my ar$e, you switch off the engine by bringing the engine to idle and cutting both magnetos off, that is like the first thing they teach you..
I think you are a bit confused about the use of batteries and generators on aeroplanes. Just like in a car, a battery is used for startup and operating electric/electronic parts, but the alternator (or generator) does the rest (from the P-51 Mustang manual):

The electrical system runs off the battery until the engine reaches 1500-1700 RPM, when the generator is cut in by the voltage regulator. Power for the electrical system then is supplied by the generator.


besides, if memory serves, back in WW2 they already made use of dry batteries, so there was no "icing" problems. If the generator fails the engine simply quits, the battery doesn't replace its work.

I don't mean to tell anyone off, but guys, please check your sources and info before posting stuff, if there's one thing that is worse than lack of information, that is the wrong one! Think of the sake of the simulator, not just the fact that you want to say yours about a subject.

SJ

Watch this excellent training video for the P47 from 21:55: http://www.youtube.com/watch?v=7Y3v1-WMJS8
And that's not the first time I've seen or read that kind of shutdown procedure.

Maybe your plane has a different engine? What is meant for a Lycoming or Continental might not apply to a Wright or Pratt.


Where did I state it otherwise? The subject was a dead generator during flight.

EVERY kind of battery, dry or fluid, loses capacity when the temperature drops.
And fluid batteries only freeze when they're flat. If charged, the freezing point is well below 0 C.

Anyway, would be strange don't you think? Starting the engine from battery, thus operating all systems, until the generator kicks in. Why do you assume that everything will stop if the generator dies? I wouldn't fly a plane that's so poorly engineered!

And the engine doesn't quit, because magneto's use their own power.
From the wiki: "Because it requires no battery or other source of energy, the magneto is a compact and reliable self-contained ignition system, which is why it remains in use in many general aviation applications."

I have experience on small engines like the Lycoming and Continental and on P&W Wasp and RR Merlin, and the procedure is the same on all. The one you see in the training video is a military procedure, but the engine is considered switched off when the magnetos are off. If you move the propeller of a plane that has just stopped and the magnetos are on, it's very likely the engine might have some pistons firing. The choice of cleaning the explosion chambers depends also on the weather and temperature conditions.
Magneto switching is a very important part of the preflight checks, before take off you bring RPM well below idle and try running the engine on one magneto at a time, all you should get is a circa 100 RPM drop. If your engine quits with just one magneto off it means that the one that is on is faulty.
A dual magneto system is not meant to burn mixture better, it's a redundant system to have extra security.

yes, dead generator means dead systems. Game over.

the batteries used on aeroplanes were meant to operate at low temperatures.

..then you don't want to fly in most WW2 planes or light sport aviation planes. If your generator fails your battery won't be able to run your systems for long. Most of the engine ancillaries like magnetoes and primary pumps (at least in WW2 planes and light aviation) are actually connected and powered by the engine by means of reduced gearings, but you will still need the generator to run other components (flaps, aux pumps, ligths, gunsight, some instruments, radio, some cooling systems etc..)

does wiki mention the fact that some systems that keep the engine running and performing adequately need electricity? You mentioned the FW190 kommandgerat which I think it's the perfect example.

S!

Even a modern jet works like that these days. If generator(s) fails then the battery keeps most important systems(back-up ones) working for about 15-30min, so not bad design. But you lose anything else requiring higher voltage so basically a jet is rendered to fly on mechanical system if there is one. The plane I work on has this.

I can't stay quiet here.
I learned to stop the engine of a c152 or pa28 or any other small plane with setting the mixture to lean!!!!
The reason is: no combustible mixture makes it very shure that there is no backfiring or ignition when the prop of a hot engine is accidentily moved, even with ignition set to on.
To stop a airplane engine by switching the ignition (magnetos) off is dangerous and just plain WRONG!!!!
And of course a airplane engine is constructed to run without external power, be it generator or battery.
Those are only needed for auxilary systems!
The "Kommandogerät" of the FW190 could be set to manual override if i.e. the electric was lost.

Actually, a lot of things are done differently depending on aircraft type. I don't know what happens in aero clubs, but in the army the preferred method to shut down pretty much anything seems to be cutting the mixture.

I saw this when serving my conscription tour as a flak gunner on Rheinmetal 20mm twins. These guns are operated with the aid of a 160cc wankel engine. During training they told us there's two ways to stop that engine, pressing the stop button or cutting the fuel supply. When we asked which is best, they told us "stop button for emergency only, fuel cutoff for everything else".

Months went by, i got posted to a unit, started doing the things a soldier does and at some point i got posted to the unit's AA company and came in contact again with the Rheinmetal guns. Each day we'd take a different gun out of the hangar, so that we checked all of them in rotation, set it up for firing, etc. Sometimes we took out the same gun after only 3 days or a week and that's when i understood their obsession with fuel cut-off. Depending on weather conditions, the exact same engine on the exact same gun driving the exact same hydraulic actuators would run smooth as butter one day and give us hell to start the next one. There's no sophisticated mixture control in that engine, just an ignition, a primer and a pull-cord starter. When people swtiched the engines off by pressing the stop button and not cutting the fuel, what happened was that unburnt fuel was left inside the engine. Depending on weather, the next time we wanted to start that engine the amount of fuel left in it could be wrong for the weather we had at that day.

If it's insufficient you can prime some extra fuel into it, but if there's excess fuel in the chamber all you can do is spend 5 minutes pumping out the excess fuel and clearing the engine by repeatedly pulling on the rip-cord starter with the ignition and fuel supply turned off,which is not very pleasant during peacetime and bad weather, or worse, during an actual air-raid. Hence the "always use the cut-off" emphasis.

It's a similar case for aircraft engines, even though they differ a lot with their huge displacement and compression ratios compared to a puny 160cc wankel, what mattered the most was making sure the engine will run when you need it the most and not that it will run for the longest amount of years. Better have a "dry" engine that needs to be primed before start, than have an overflooded engine that needs to be turned without ignition to be cleared before being primed before being started during a scramble call.
That's the reason most of the restored warbirds are ran at different power settings than the wartime values, in the war they wanted to ensure performance when they needed it the most, but in the airshows the main care is to ensure maximum component life so as to keep them flying for longer.

Also, you say this
but it makes it seem like it all goes dark in a split second. What you say next is a better description

"For long" being the operative phrase. If you switch off everything you don't need, there's an airfield within 20 miles of your position and you get priority/emergency clearance by ATC, i guess you could make a safe landing without a generator, running only a couple of instruments from the battery. Of course, it would be a different story at night where you need more radios, more light equipmeent and so on.

Actually that is exactly what azimech was hinting at. Dead generator--->need to conserve battery to RTB--->player will have to choose what to keep running and what to turn off=interesting gameplay.

S!

In modern jets if you lose the generator then batteries are designed to work for about 30min(back-up instruments and some other systems), to give you time to get to safe or even land if possible. The engines run and if they do then are the hydraulics working, but with batteries the FCS computers won't work as they require more voltage than a battery can provide, so you are on a backup system that gives limited aircraft control. This causes landing speed to be high thus in most cases it is safer to eject after flying out to a safe area. In a WW2 plane you could land easier and have less hassle if losing the generator and running on battery..depending on the plane of course.

I haven't made myself clear:

switch off procedure:

1) taxi to parking
2) ancillaries checklist (flaps, brakes etc..)
3) mixture to lean
3) throttle to idle/cutoff (if present)
4) engine stops detonating
5) magnetos off

now the engine is off

you can take the engine to idle and switch it off with the magnetos, which is not dangerous at all, it is actually considered safer because even if there is some mixture residue (you might have a faulty inlet valve for instance), there will be no spark from the plugs in case of accidental prop swinging.

I didn't know you could override the kommandgerat, where were the manual controls for the engine?

Guys, I have hundreds of hours on single engine propeller planes, and I don't mean to brag but I think I quite know what I'm doing when flying (and switching an engine off).

Blackdog, I know it sounds like that, but in some planes a dead generator really means the games are over in a split second.

Comparing the use of high compression engines with low ones (aeroclub boxer engines vs wartime radials or inline) is improper. We takeoff the Mustangs with never more than 75% throttle simply because there's plenty of power to do everything and above all you don't want to over stress cylinder banks that are 60+ years old, but in the warbirds circuit there are several pilots that firewall their engines, which often means catastrophic (and very costly to repair) damage. We had a case a couple of years ago of a mustang pilot who used to takeoff at full military power (or WEP) and who had a major failure fortunately once on the ground.
Cutting off engines by leaning the mixture is considered a bad habit by some, while others think it's perfectly fine. I think it's all down to the machine you're flying with and environmental factors.

and once again, an engine is not considered safely switched off until the magnetos are on, and that is the same for every plane.

Military procedure yes, and we're talking about a military flight sim.

Here's a nice read for you, dual ignition really is meant for a better burn in those big-bore engines. It even lessens the risk of engine knock!
http://www.avweb.com/news/pelican/182132-1.html

That's not what I read in electrical schematics of aircraft.

Batteries warm up while charging, and during flight, they are continuously charged unless charging is shut off manually.


That's why I started the topic in the first place! The battery won't keep it for long is something else than immediately dead systems.

Kommandogerät is one example, prop pitch governor on the P38 is another. The mags will work anyway and if the rest fails, you still have a chance to get home.

Alfa Romeo have often employed dual ignition since the 60s for a leaner burn and higher power. Igniting the mixture at two different points caused a quicker burn and allowed tighter timings.

Don't know anything about this regarding fighter a/c, though. Presumably if dual ignition was used to tighten timings, knock would become a serious issue if one circuit was knocked out. OTOH, a dual system would provide redundancy but only a tiny increase in power if the ignition timing was the same as a single-ignition setup.

dduff

Thanks for the clarifications sternjaeger. It makes more sense now and yes, i agree that for an engine to be considered safely off the pilot needs to also switch off the ignition and not just the fuel supply :grin:

The KG is not driven by the battery or the generator, It is mechanical in the BMW801 series and hydraulic in the Jumo 213 series. It uses the mags and is not affected by a loss of systems electrical power to advance the timing.

The VDM propeller only uses electrical power for emergency operation which the KG does not control. In normal operation it is a hydraulic governor and is a normal CSP.

Very interesting!

Would you happen to have some documentation on that device? I'd love to study it's details!

double ignition gives an overall better burn performance, but it's more relevant on small engines than on large bore ones. A 100RPM drop on a 1650HP engine is negligible compared to the same drop on a 150HP. Besides don't give credit to stuff just because you read it on the internet dude, there are several inaccuracies in that "report", which by the way is on the detonation issue..
In a high performance military aeroplane redundancy has priority, especially considering the huge amount of power available.



it's probably because you don't know how to read them. And that's also why many planes now have backup generators.

...so how can they freeze? And even if they did, batteries are not used during flight, it's all fed through the generator. Another thing, they're not continuously charged since they could overcharge. The circuit overload is controlled by means of breakers that... hang on a minute, have a read for yourself: this is the P-51 Pilot's manual, not some random guy's dissertation on detonation
P-51 Mustang Pilot's Manual

browse words like "battery" and read about how the electrical circuit works.. also read the engine turn off procedure and see how you want to switch the plane off. Magnetos go OFF.

It's all down to the kind of aeroplane we're talking about.

again, it's all down to the plane. See what a Pilatus Porter pilot thinks of generator failures ;)

...and again, I don't mean to sound harsh guys, it's just that I'm writing this stuff mostly on the run, no hard feelings, just get your facts right please, again it's for the sake of the sim.

Why don't you point out exactly which inaccuracies you've seen in that report?

Backup generator, APU's etc... not much room to put them in a fighter back then. I know of multi-engined planes having multiple generators.

Why don't you send me an electric schematic of an aircraft of that period with the request to explain it to you? I haven't learned modern high-voltage AC systems but that old stuff is pretty transparent.

First of all, of course you switch mags off, but the sequence differs per engine or situation. I never suggested leaving the plane with mags still on.

I read nothing new in that P51 manual. Very standard tech for that period. I hoped to find something new but that small portion about the electrical system is not interesting. The only thing I like is the automatic manifold pressure regulator, That means in the future P51 drivers in IL2 or SOW will have less risk of wrecking their virtual engine. Maybe the Rolls Royce Merlins have it as well...

Overcharging happens when a voltage regulator fails, not before. A voltage regulator back then was an electromechanical device which dynamically relayed overvoltage into one or more resistors, changing the power into heat. Now i've seen a lot of those old things broken and even nowadays the electronic versions often break before the alternator itself does. Usually those old flight systems operated at 14V or 28V while the battery provided 12V or 24V. The extra 2V or 4V was, and is still used, to charge the battery. A battery won't charge to it's full capacity if input voltage is the same as battery rated voltage.
Now if the voltage regulator fails, you might wreck your battery very soon because electrolysis increases in an enormous rate, producing a lot of heat. But, the battery is a buffer, it usually keeps the increase in voltage within around 50% but it's capacity starts to drop rapidly. Some batteries can burst. If a battery bursts or when it cooks dry, it's capaciting effect stops and the peak voltage can grow with 200% or even 400%! I've seen it happen. One guy touched the lead of a running alternator which normally produced 6 volts, he got a jolt and jumped in the air. I've also seen a very hot and deformed battery which got us all nervous, the alternator provided 18 volts instead of 14 regardless if the mechanical voltage regulator was connected or not. I had to pick four regulators off the shelf, the first three were broken.

That's what those switches are for, Battery on/off is for switching power when you park or want to start, generator off for the safety of your electrical system. The generator provides the power to the plane's systems when running enough RPM, the battery is the buffer which compensates for peaks & jolts which cannot be compensated for by a failing voltage regulator, and heavy undervoltage situations. These can distort the functions or be harmful or even fatal to delicate systems like radio, navigation, instruments or radar.

Remember that generators provide DC and they start to provide a meaningful voltage at higher RPM's than the later DC rectified alternators. The fact that the P51's generator only starts at 1500 RPM while a modern alternator does that at 850, is the perfect proof. It also means that an engine that runs too slow while a lot of electrical systems are running can create a system's wide voltage drop, possibly more than the 2V or 4V, which is more than the margin the electronic equipment was designed for. The battery compensates for those moments, adding up where the generator fails to provide.
Another problem which generators have is the fact they can be used as an electric motor, with the battery providing it's power. A problem alternators don't have. This was the time before the invention of the high-power diode. The voltage regulator had a built-in function to disconnect the generator from the system when generator voltage output dropped below that of the battery.

I think ANY pilot would get nervous if his generator fails ;-)

Pilatus Porter manual from 1972:

http://avsimrus.com/f/documents-16/f...n=download&hl=

Page 1-17.

Have fun!

S!

Good stuff here. At work when the guys flying the propellor planes(trainers/liasion), they do cut the engine by using mixture IMMEDIATELY followed by turning off ignition and hanging the key. Then they consider the engine OFF.

Here a link to the startup & shutdown procedure of the Allison:

http://rwebs.net/avhistory/opsman/pursuit/section2.htm

And here procedures for the P51, Only the D variant is mentioned so it must be the Packard Merlin variant.

http://rwebs.net/avhistory/opsman/pursuit/section7.htm

However, I'm starting a new topic to try and combine as much official manuals of WW2 aircraft we can find.

I'm sorry mate but "we" who? You really switch off your propeller plane by cutting the mixture? That is one helluva dangerous game man.. If I did something like this with my instructor would have kicked my ar$e, you switch off the engine by bringing the engine to idle and cutting both magnetos off, that is like the first thing they teach you..



Most piston planes I've been in involve shutting off the engine by setting the mixture it to idle/cut off, thats why it's called "cut off". The idea is that you starve the engine of fuel, so that you are not left with unburned fuel in the cylinders or manifold. After the engine is off, the mag switch and battery master switch goes to OFF and your safe.

I have mainly flown 172s and 152s but the shutdown/parking checklist was generally something like:


mixture to the idle cut-off position.
fuel selector valve to the "off" position
turn off the master switch
turn off and remove key


A random google turned up this 172 POH in pdf format:

http://www.redskyventures.org/doc/ce...o7-scanned.pdf

It has no standard shutdown checklist but the shutdown due to engine fire in flight emergency procedure starts with mixture to idle cutoff.

The "securing aircraft" checklist does mention electrical first but by that stage the engine has been shutdown.

...so rumours of a "seat of the pants" in the box are exaggerated then...

I have the KG manuals, BMW801 series, Jumo series, and VDM manuals. Parts, service and installation for all of them.

We even have a working KG awaiting installation on the engine we will install in our FW-190F8 to fly.

Unfortunately I am overseas on a contract at the moment and will not be back in the US until after the Holidays.

Heh, the new stuff A2A produces is much better.

http://www.youtube.com/watch?feature...&v=JCLMgLB9Qlo

This would be beautiful to have in SOW one day, even payed 3d party.

As much as I would love to, I have no time or interest to go into the finest details really. To sum it up let's say that when you lay down such researches on such extensive subjects you might want to take into account more variables, but then you'll end up generating a whole manual on the subject (and probably a set of manuals for different engines as well). A lot of self proclaimed experts like passing their times posting diagrams and what not on the internet, they're the kinda loners that spend a lot of their time with the heads in the engine bay of their aeroplane more than in the air.. But then again, each to their own really..

oh u'd be surprised to see what they managed to cram in an aeroplane back then. People have a simplistic and somehow naive view of WW2 era fighters, but the complexity of the systems is surprising, especially on aeroplanes which used a lot of radio or electronic navigation devices in WW2. It wasnt all about fighter boys and bombers, electronic warfare had an impressive development in very few years.

because they're very hard do scan, considering that most of them come in folding sheets as long as the plane! I tried to google for some basic ones, but couldn't find much, only ancillaries (which are quite complex per se).
You need to find maintenance manuals to get some wiring diagrams, I'm sure that the ones of a FW190 would keep you busy for a bit ;)

I think this is where the misunderstanding started.
but you might want to reconsider some of your sentences on the importance of magnetos in the early posts you made and I referred to. Again I'm just trying to explain where I think you expressed yourself improperly.

Very standard tech for that period? Seriously? :rolleyes:
A high energy performance, laminar flow, low consumption, propeller fighter which could deliver punch and fight hard at all levels all the way over Germany and back is a bit more than very standard to me man..
Just the aerodynamic research in the development of the radiator scoop and wings is a good 10 years ahead of its contemporaries.

The electrical portion was to explain quickly how it works on a real aeroplane, that's it.

...aaaand that's why there are breakers on aviation circuits..

I'm sorry man, but the impression I got here is that you are doing a lot of copy/paste to show that you know on the subject, while I'm addressing other points that you don't seem (or want?) to see..

glider pilots?? ;)

I am NOT saying you don't take the throttle to idle/cutoff first, I'm saying that an engine isn't considered OFF and safe until magnetos are OFF. Thinking that an engine is off without magnetos off is a common misconception.

Did you even read the whole article? I strongly doubt that! It involves LOGIC, and that's the glue in that whole damn reading. Using my own brain, I found it perfectly plausible.

B17 is a very good example, but that's no fighter. Anyway, the way A2A simulations has implemented the features into FSX is a nice guide how the complexity of military simulation could become.

I read them at breakfast for my entertainment. Don't bother, i've got enough lying around.

The FW190 itself is not very interesting. The only thing that's worth to me is the internal operation and structure of the Kommandogerät, although I've got a very good hunch how it operates.

You seem to be the only one having a problem with how i'm expressing myself.

I've never cared for aerodynamics. I've always been interested in hydraulics, electrics and internal reciprocating engines. In those ways the Mustang is a very standard beast. Give a stone brick a big enough engine and it will fly. Do I like the engine? Then I'll like the brick. I don't really like the carburetted V12, it's all injected radials for me.


Yes, and the point was/is YOU DON'T DISCONNECT YOUR BATTERY FROM YOUR SYSTEM WHILE FLYING UNLESS YOU REALLY NEED TO!

Man, you're a joke. I've confronted you with a lot of errors in your statements, often with material from the era, and you twist & turn the whole time and ultimately insult me with copy & paste work, while I write using my own friggin' brain.

I don't give a Flying F*$^ whatever plane you've driven, that doesn't make you a technical expert all of a sudden and it shows. You think you're smart while you ignore evidence I place under your nose and suggest that I am trying to avoid the subject? Get lost.

Now go fly your plane and don't waste any more of my time.

I did, it's not the first time I've been pointed to it. I assume I am entitled to my opinion as much as you are, live with it dude. I am not saying you shouldn't believe it, but please don't come around telling me what is right or wrong.

There are fighters that have very complicated electronics like the Me110 night fighters and successors.. anyway I agree about the A2A stuff, it seems really interesting!

lol I read only newspapers and email in the morning, but each to their own ;)

dude, I'm just saying that the way you put things originally sounded a bit wrong, then you got all wound up and started enumerating a lot of babble that had nothing to do with what I said, don't take it personally..

I say that you can't look only at certain aspects of an aeroplane and say "I don't care about the rest". The Mustang and Spit Mk.IX had pretty much the same powerplant, but the Mustang had the edge on performance because of its extremely clean aerodynamics and build. Uh and only the early marks of Merlin engines weren't fuel injected. Having dealt with radials and inline engines I tend to agree with you: radials have a different fashion appeal and they're VERY sturdy, but the performance and technology of a Merlin (or a DB605) is something superior.

I never said you do, the electrical plant does it for you automatically.

I'm sorry, but where are my "lots of errors"? I don't need to insult you man, you're just going off topic talking about stuff that had nothing to do with the original point. Relax, we're all adults here (or are we?)..

whoa, that's harsh.. I'm not a technical expert, but I spend a lot of time with our mechanics in the hangar and I think I have enough on hand experience to be confident enough about what I'm saying.

I don't mean to waste anyone's time, and if anything you should show some respect to people that you don't know and are trying to have a civilised conversation. Uh and another thing, accept the fact that despite all of your breakfasts with manuals and internet knowledge you might still be wrong man. Now relax and go back to your manuals while I'll get my hands dirty on a real aeroplane...

Peace out..

Heh, I installed a set of GAMI injectors once.

Great question, Azimech!

More interesting stuff to read here...