combat power question?

[Nathan]

Maybe a dumb question but, during air combat say with a P-40 or P-51. Would full power be given during the entire combat? I know some combat doesn't last long. But some last 10-15 minutes worth of throwing around in the sky. Would that be hard on the engine? I know a lot of the piston engines cant run on full for very long right? Could cause overheating or worst?

Handing this question over to the experts..,
-Thanks, Nathan.

[Pat Carry]

Hi Nathan, Remember there are no dumb questions on this forum! As far as combat power, I am far from being an expert in this matter but from what I have read in books down through the years combat power was used very sparingly for short periods of time when the pilot had to get the h-e-l-l out of dodge in a hurry.

[FG1D Pilot]

Hi Nathan, Remember there are no dumb questions on this forum!

But you will get dumb answers and smart ass ones too. "War Emergency Power" was just used as the name infers and as Pat said. The throttle quadraunts have "breakaway" safety wire that breaks when you go to "Emergency Power" that does two things: Keeps you from going there inadvertently, and lets the ground crew know you went there (advertently).

[Enemy Ace]

During Air Combat Manuvering the throttles will be moved rapidly throughout the range from idle to max power as the situation changes second by second.

[Oscar Duck]

engine life was not a consideration when fighting to the death. Just read a book by a RAAF P-40 pilot in Nth Africa where he said that he used "6 feet" of MAP [72ins] to escape a bad situation..normal max MAP around 57ins

[Dudley Henriques]

Maybe a dumb question but, during air combat say with a P-40 or P-51. Would full power be given during the entire combat? I know some combat doesn't last long. But some last 10-15 minutes worth of throwing around in the sky. Would that be hard on the engine? I know a lot of the piston engines cant run on full for very long right? Could cause overheating or worst?

Handing this question over to the experts..,
-Thanks, Nathan.

Not a dumb question at all. In fact, I had this one thrown at me at every show we ever did as people came up asking about the airplane.

Most of the fighter pilots I've known personally through the Fellowship all seem to share a common generality when addressing this issue.
Here's the long pedantic version first;
Almost to a man, and this would include Bader, Boyington, RL Scott, and Sakai, all said that upon engagement, they ran their props up all the way and played their manifold pressures as needed with the props in low pitch high RPM. I have to say I've done the same when engaged in mock ACM against another fighter.
War Emergency Power as others have corrected noted was not used indiscriminately by anybody with above room temperature IQ. You worked the throttle against the WEP gate but saved that as a last ditch resort when defensive. Notice I said defensive. There should never be a situation in prop ACM when OFFENSIVE where the use of WEP is warranted. It was mostly used defensive 1 vs many where nose to tail separation was desperately needed to save one's butt as decreasing airspeed while defensive began to become a negative issue defensively in negating cutoff from an aggressive shooter with either a Ps advantage, a positive rate of closure, and a radius of turn advantage within favorable angle off for the shooter that was in imminent danger of becoming a tracking solution for him with the defensive fighter unable to force an overshoot in the plane of his turn.

Now the short story;

If you need WEP, you've done something wrong.................but use it if you have to .
Hope this helps a bit. )

Dudley Henriques

[Bill Greenwood]

Nathan, the Merlin in a Spit Mk IX burns 180 gal per hour at full throttle. You are not going to burn up 45 gal or half your cruise fuel by using full power for 15 min unless you have to.

Also, most combats, the actual plane vs plane usually was a matter of perhaps one or two minutes , which might be full throttle, but 15 minutes would be almost unheard of. Galland himself told me that, "I don't turn with Spitfires, I make one pass and go home to drink schnaps". I heard Gen Rahl say much the same and read Eric Hartmann to the same point, that most of his victims never saw him coming and one pass was all that was needed.

Also, even in something like a P-51 with more fuel and range you may be escorting bombers so need to match their speed, perhaps about 190 mph over long distance, at least until actually in a fight.
Of course if you have a 190 on your tail, I have read of some guys like Robt. Johnson who said they were practically bending the throttle lever trying to get more in his P-47.

I have the Merlin book that quotes bomber pilots who also did whatever they had to to survive. One Wellington pilot had an engine hit near Nuremberg, also picked up ice and came back to England with the other at full throttle for 5 hours "with the needles hard against the stops".

[gregv]

interesting topic!

So if the throttle was pushed "through the gate" breaking the wire, what did this mean to the ground crew? Was the engine inspected for any damage, or was it replaced automatically?

cheers

greg v.

[Dudley Henriques]

interesting topic!

So if the throttle was pushed "through the gate" breaking the wire, what did this mean to the ground crew? Was the engine inspected for any damage, or was it replaced automatically?

cheers

greg v.

Wartime suggested limit on the 51 was 5 minutes max. Notation in the form 1A when used.
On the civilian side of the Mustang equation, I know of no civilian operators who have used WEP for any normal V1650-7 use outside racing and even racing is a whole different ballgame that goes way beyond WEP use.
In our airplane, I had a solid metal strip spot welded across the point where the wire would have been that formed a solid stop limit that couldn't be exceeded, and this was when 130 octane was available.....I should say affordable really ). When 100 octane became the norm, we limited at 55 inches anyway so even the welded stop became history

The thing about WEP in combat was that no pilot flying single engine fighters, ESPECIALLY in situations where long cross country flight was required before reaching the combat area wanted to abuse their engines. Failure over enemy territory was self explanatory and the use of WEP for ANY reason increased the odds for engine failure even if used correctly. The guys were quite understandably VERY aware of these factors and managed their engines with this in mind. If you ask ANY Mustang pilot who flew the airplane in combat what instrument he was focused on while on missions, the answer invariably will be the coolant gauge, and this answer is even before you get into the use of WEP.
Dudley Henriques

[FG1D Pilot]

interesting topic!

So if the throttle was pushed "through the gate" breaking the wire, what did this mean to the ground crew? Was the engine inspected for any damage, or was it replaced automatically?

cheers

greg v.

Inspection for sure. Normally it was easier to remove it and send it back to depot maintenance. I once spoke to a P51 crew chief that told me they never trouble shot in the field. If they spent an hour or two trouble shooting, then had to change engines, they wouldn't have time to get it back in the air the next day. It was easier to just change the engine and let the boys back at depot play with it.

[b29flteng]

As an aside to the question, on C-130s, when cold outside it was possible to over-torque the engine, i.e. overboost. The engine mounts were designed for 19,600 inch pounds of torque and you could easily get 25,000 inch pounds of torque on a cold day. The result is an inspection of the engine mounts for damage.

[AvroAvian]

I have read in both the Allison V1710 and the Packard V1650 manuals that the time spent at WEP was to be recorded post flight in the Form 1A and when the total time added up to five hours, the engine was to be pulled for overhaul. Time at very high power settings rapidly increases the wear rates in the top end of the engine, ie pistons, rings and valves. Hence combat engines were generally good for around 250 hours, compared to civilian operators nowadays getting up to 1000 hours before overhaul.
I did read of a guy in a P51 who was so sh1t scared after being jumped over, IIRC, Holland that he WEP for half an hour down on the deck to get away.