military power vs cruise

[Captain Virgil Hilts]

I don't have the time to look it up right now, so I'll ask.

How many planes could, in real life, cruise around at military power all the time without overheating? I know many if not most of the liquid cooled planes could not, I'm not real sure about air cooled radials.

The point being that I think the fuel modifier is a good idea and should be set to at least 1.5, and 2 seems to be a lot better. But that does not stop some planes from flying at military power constantly, which I know in many cases is entirely unrealistic.

But rather than allow planes with less fuel capacity to carry a greater percentage of fuel when fuel is restricted I think it is more correct to prevent planes from flying at military power when they should be at cruise.

And I like Pyro's suggestion that fuel porking be severely curtailed. But rather than FORCE a limit, I'd rather see it made more difficult to actually damage or destroy fuel supplies.

[Innominate]

Isnt military power the maximum power setting an aircraft can maintain indefinitly? (Till the gas runs out anyways)

[Captain Virgil Hilts]

Originally posted by Innominate
Isnt military power the maximum power setting an aircraft can maintain indefinitly? (Till the gas runs out anyways)

No, military power is actually the term for "100%" power, just before the setting referred to as WEP. Military power cannot be maintained indefinately. At least on most liquid cooled aircraft engines.

For example, 54" manifold pressure is military power for the P-38, and also takeoff power. The manual and other sources state that military power (54" manifold) is available for 15 minutes. WEP, which is 60" manifold (prior to the release of the restrictions due to fuel problems) is only avaialble for 5 minutes. After 15 minutes of military power, or 5 minutes of WEP, full throttle (military or 54") is not advised because the engine has reach maximum sustainable operating temperature and will begin to overheat. Continued operation at military throttle will damage the engine(s), while it may not happen instantly, it WILL happen.

[GScholz]

It varies from plane to plane and engine to engine. For instance the 190D-9 modelled in AH could stay at "combat and climb" (MIL) indefinitely, but the 109s had a 30 minute limit to the same power setting due to overheating.

[Mak333]

I totally agree with the Cap'n here on this one.  The use of fuel needs to be modified more to the extent in which it would affect how players use their engine power.  In reality, it is different than it currently is in AH2.  I do like how they increased the fuel burn rate and how it makes a difference in distance and time as far as certain manifold pressure settings and rpm's go.  But it is not enough to stop players from using wep most of the time aswell as military power.  Overheating the engine would be something I would REALLY like to see.  From my standpoint, AH2 is putting more of an emphasis on the realism of the planes and environment, and to be responsible for managing your plane (as opposed to shooting them down) should be implemented into the game aswell.

[Karnak]

In one of my books it gives range for the Mosquito at boost +14lbs, which is MIL power for most 1943 and later Mosquitoes.  Now, I don't know if that is simply inferred data or actual practical data, but it does imply that the Mosquito could run at MIL power until it's tanks ran dry.

I also recall a test on a R2800 where it was run in the factory at WEP power for 96 hours straight.

[Batz]

109s had a 30 minute limit to the same power setting due to overheating.

They didn't necessarily overheat over 30 min but the longer you ran past those the limits the more wear the engine suffered. Which meant reduced eng life.

Some La5FNs couldnt run wep over 2 minutes do to overheating problems. Some planes like the 51 could run all day at mil .

My point is its too random to say ok 30 min for this plane 2 minutes for that plane etc....

As Pyro explained in another thread Power limit restrictions were to decrease fuel consumption and to keep as many aircraft in service as possible. It wasnt because planes overheated if you ran 2 min over the power limit.

[Orig]

I think it was in one of Chuck Yeager's books where he describes how he and his crew chief would sometimes figure out how to slightly boost power in his planes because he knew that the full-throttle power settings were usually conservative and he could get away with upping the max power if he didn't otherwise abuse the engine.

I don't remember many of the details though, but in once case he bent in the engine trim tabs on his F-86 to slightly boost exhaust temperature/pressure and get a little more thrust.  It makes me wonder if he and his crew chief adjusted the throttle cams and stops in his prop fighters as well.

[MrWimpy]

I know from the various books I've read that there was apparently a wire or something that blocked WEP.  This was apparently there to keep the pilots from going to WEP until they really wanted to, in which case they would shove harder and break through the wire.

So far as I am aware, this was the setting that could only be temporary.

But what do I know, I'm just an amateur historian.  ;-)

[F4UDOA]

It is important to remember that in between Mil and Max cruise was normal rated power or METO power. That usually carried a much longer rating than mil but more performance than mil.

Also keep in mind that flying at mil power was more limited by range than actual engine tolerance.

One of the more important aspects of aircraft design was cruise speeds at low power settings. This was important for two reasons.

1. Range, obvious

2. When cruising in nme terratory it was import to keep your speed high in case you were jumped or saw an opportunity for combat. Read any transcript of pilot action and you will see when ever in a combat area cruise speed was always increased to something close to mil power to avoid being jumped.

One of the huge advantages the P-51 had was a very high cruise speed at very low power. It could cruise at 400MPH at minimal power at 25K. This gave the Pony a big head start and almost immunity to being overtaken by slower A/C.

In post war racing the Mustang set records by flying from Cleveland to LA non stop no DT's at 430MPH plus average speed. That is in the modern commercial speed range!!

[ergRTC]

I hope this gets well enough developed where something like high cruise speed becomes an advantage.  Cruising at 160 mph in a hurricane really makes you respect planes like the mustang.

[Hyrax81st]

Orig wrote... "It makes me wonder if he (Yeager) and his crew chief adjusted the throttle cams and stops in his prop fighters as well."

I remember that Yeager was a crew chief himself, before he ever got selected for pilot training... reallllllly good with a wrench. I'm sure he came up with quite a few good modifications with his own chief.

[GScholz]

Well ... "modifications" is probably a too strong a word. There is a limit to what you would dare do to a plane you would have to fly for hours over hostile territory in.

[Hyrax81st]

Which is probably what made Yeager fairly "unique". He always pushed the edge of the envelope.

But you're right, I think he would have been careful not to field test a modification on a mission.