Modelling engine wear and WEP limitations

[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....

[Seadog]

Originally Posted by Crumpp

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]

Originally Posted by Seadog

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.



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]

Originally Posted by Crumpp

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



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/showpos...5&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]

Originally Posted by ICDP

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.



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



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.

[Seadog]

Originally Posted by Crumpp

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.