Design your own airplane

[RAM]

Yes, but the Mustang is smaller than, for example, the Tempest, and highly streamlined.

Well, IIRC the Tempest had also a laminar flow wing and was (except for the chin radiator) pretty well streamlined. And had 2400hp to boot. And was quite slower than what those charts show.

Something doesn't add up here...

Well, lower drag means your horse power is used more efficiently in the climb too. Also, you'll notice that those extreme climb numbers for the P-51H are at 8,000 lbs. That is not all that much higher than the normal loaded weight for a 109-K4, and the P-51 has a larger wing area.

Not really into aerodynamics, but I think wing area says nothing about climbrate. Wingloading does (when taking also in account wing shape efficiency, I think the term is liftloading) but not THAT of a difference....Lower drag should mean a difference too, but not that big given that climbs are done at low speeds.

If those charts showed a climbrate of 5000fpm for a 8000lbs mustang with an engine giving 2000hp I'd be suprised, but I'd accept it. We're seeing a climbrate of +6000fpm at sea level for a 8000lbs plane with 2000hp. In comparison a Bf109K4 (7400lbs and 2000hp) climbs at 4600fpm more or less. We're talkiing about a 30% discrepancy with another plane with the same power but 600lbs more. BEtter aerodynamics and a better wingloading can't explain such a discrepancy AFAIK. Not to mention that the curve of 10.000 pounds show a climbrate of around 4800fpm, which still is 200fpm more than the k4, for a plane 2600lbs heavier and the same power available.

AS I said, something doesn't really add up here. Not that I don't trust widewing (he's one of the guys who've shown the best raw data I've ever seen on WWII planes here in AH boards), but I can't accept those numbers without a proper explanation...Granted that I'm not an expert (by far), but still 6000fpm@sl its too big of a number to accept it lightly.

[Sol75]

im not exactly an expert either, however, logic stands to reason that, in addiition to the pure HP rating, your Supercharger settings would come into play for horsepower @ a given altitude, and your prop design would play a vital role as well.  Some props simply climb better than others.  (thus why we have variable pitch props!) im sure that in addition to prop pitch, prop chord, thickness, etc would come into playa s well, seeing as a prop is simply an airfoil perpindicular to the aircrafts thrust line.

[BnZs]

Well, IIRC the Tempest had also a laminar flow wing and was (except for the chin radiator) pretty well streamlined. And had 2400hp to boot. And was quite slower than what those charts show.

You've got to wrap your head around just how slick this airframe is...

The really jaw-dropping is looking at even a P-51D compared with a Merlin-powered Spit or a Fw-190A. These are smaller airplanes that are quite low-drag themselves, with as much or more HP, yet he P-51 manages to be ~20mph or more faster than all of them at S/L. And the H featured some streamlining improvements over the D.

Also, IIRC, maximum WEP for the H was something like 2,200 HP.

[Pannono]

Gimme a F4U-4 with an extra pair of .50s

[Widewing]

Well, IIRC the Tempest had also a laminar flow wing and was (except for the chin radiator) pretty well streamlined. And had 2400hp to boot. And was quite slower than what those charts show.

Something doesn't add up here...

Not really into aerodynamics, but I think wing area says nothing about climbrate. Wingloading does (when taking also in account wing shape efficiency, I think the term is liftloading) but not THAT of a difference....Lower drag should mean a difference too, but not that big given that climbs are done at low speeds.

If those charts showed a climbrate of 5000fpm for a 8000lbs mustang with an engine giving 2000hp I'd be suprised, but I'd accept it. We're seeing a climbrate of +6000fpm at sea level for a 8000lbs plane with 2000hp. In comparison a Bf109K4 (7400lbs and 2000hp) climbs at 4600fpm more or less. We're talkiing about a 30% discrepancy with another plane with the same power but 600lbs more. BEtter aerodynamics and a better wingloading can't explain such a discrepancy AFAIK. Not to mention that the curve of 10.000 pounds show a climbrate of around 4800fpm, which still is 200fpm more than the k4, for a plane 2600lbs heavier and the same power available.

AS I said, something doesn't really add up here. Not that I don't trust widewing (he's one of the guys who've shown the best raw data I've ever seen on WWII planes here in AH boards), but I can't accept those numbers without a proper explanation...Granted that I'm not an expert (by far), but still 6000fpm@sl its too big of a number to accept it lightly.

If we look at the power ratings of the V-1650-9, we see that it is rated at 2,240 hp @ 90" MAP with water injection at 3,500 feet. See power chart below.

When we look at the drag coefficient of the H model, we see that it comes in below 0.0176 for the P-51D at 0.0167. Compare that to the Tempest which is approximately 0.0250. You cannot get around the massive radiator hanging out in the wind, plus the enormous size of the Tempest. Gains in drag reduction for the laminar airfoils are not significant in actual practice and those gains (assuming the wing is spotlessly clean) don't really show up until speed is in excess of Mach 0.6 (conventional airfoil drag curves begin rolling up around Mach 0.6).

Thus, in comparison to the Tempest, we have the P-51H data reflecting an 7,500 lb fighter with a significantly lower drag coefficient, and similar available power. It should run away from a Tempest. Load the P-51H with full internal fuel, bringing its weight up to 9,500 lb and the climb rate degrades substantially. Yet, it is still better than the Bf 109K-4.

I haven't even mentioned one important reason for the P-51's (any P-51) speed advantage. Its carefully designed Meredith Effect sealed heat exchanger generated considerable greater thrust than any other installation in a WWII fighter.






My regards,

Widewing

[RAM]

The power alone is enough to convince me. I thought the P51H engine was rated at 2000hp, if it's 2240hp, we're in a completely different situation than the one I thought about.
I know about the meredith effect and how the P51 got a huge speed advantage out of it's ventral radiator. But almost 250hp more are a big difference here, both in climbrate and speed.

Still, there's a discrepancy in the speed charts you've posted. The one in the previous page gave the P51H a 425mph speed@SL. The last one you just posted shows 410mph@SL (which is fast enough, lol) With the extra power explaining the climbrate and the speed, and 410mph@SL instead of 425mph, I find the data much more believable now.

Thanks for the explanation, widewing. That thing was not a plane, but a winged rocket...of course I agree that if it ever sees the light in AH, it should be perked somewhere between the tempest and the 262. What a plane.

<S>

[Angus]

When did it enter service,and if in WW2, did it see action??

[Widewing]

When did it enter service,and if in WW2, did it see action??

On the day Japan surrendered, 370 P-51H fighters had been delivered. Approximately 57 had been delivered to the P.I., with at least 17 ferried to Iwo Jima. Flight ops began near the end of July, with P-51H hops flown for familiarization. Only about 6 were released to squadrons before Aug 7. About a week before the surrender, a few of the new Mustangs were flying local combat air patrols. None, however, encountered Japanese aircraft on these patrols. Guns were never fired in anger. No P-51H types were going to fly escort missions until they had established that they were bug free. As far as anyone can determine, the H models would not have flown over Japan until early September.


My regards,

Widewing

[Saxman]

Which arguably rules it out from addition to the game. Otherwise HTC may as well add the Bearcat, too.

[moot]

No reason not to, if everything else on the other side of the threshold is already in.

[Bronk]

Which arguably rules it out from addition to the game. Otherwise HTC may as well add the Bearcat, too.

Boooo.... f-7f better. 

[Angus]

On the day Japan surrendered, 370 P-51H fighters had been delivered. Approximately 57 had been delivered to the P.I., with at least 17 ferried to Iwo Jima. Flight ops began near the end of July, with P-51H hops flown for familiarization. Only about 6 were released to squadrons before Aug 7. About a week before the surrender, a few of the new Mustangs were flying local combat air patrols. None, however, encountered Japanese aircraft on these patrols. Guns were never fired in anger. No P-51H types were going to fly escort missions until they had established that they were bug free. As far as anyone can determine, the H models would not have flown over Japan until early September.


My regards,


Widewing

Sad, it doesn't meet HTC's criteria then? (Fired guns in anger?). What of the F7F and F8F as well as DeHavilland Hornet then? Guess not....
Sort of tickles one for a Korea part to AH, - but if I recall right that one is not on the drawing board...

[Widewing]

Sad, it doesn't meet HTC's criteria then? (Fired guns in anger?). What of the F7F and F8F as well as DeHavilland Hornet then? Guess not....
Sort of tickles one for a Korea part to AH, - but if I recall right that one is not on the drawing board...

I wouldn't push for the P-51H, although I'd be quite happy to see it. Like the F7F-3N, it was in the war zone, but never had an opportunity for actual combat.

What I would like to see is a 150 octane option for the late-war USAAF and RAF fighters, perked as needed.

This would make the P-51s competitive with the La-7 and Tempest down low and climb with the late 109s.






Certainly, this is within the scope of the game.


My regards,

Widewing

[Rebel]

Which arguably rules it out from addition to the game. Otherwise HTC may as well add the Bearcat, too.

There's actually a case to add the 51-H.  While the guns were never fired in anger, it wasn't for a lack of trying.  They served active sorties in the theatre in a time of war.

The F8F's weren't even delivered yet, strapped to the deck of a carrier, and on their way, halway across the pacific when the surrender was signed.


Widewing- What planes would you make available with the 150 octane upgrades?  Did any other countries have higher grade AV Gas? 

While we're on the subject....what would you think about perking fighters who had common field mods?  i.e. the P47's modified waste gate to allow a D-11 to throw down over 70" hg, etc.  (I think that's right- Bob Johnson's Thunderbolt was SCREAMING fast, forgot what he said his manifold pressure was)

[WWhiskey]

i have hoped for a while now that we could get perked field mods, such as the p-47 with 80psi. boost!
 i am not sure how to do it yet!
but i for one would be burning alot more points than i do, altho some players still might fly a few perked rides, right now unless i want to ride in a 262 there is no other reason too use them, the 163 option is almost off the table on most of the maps we use now, unless you want to ferry one with its trolly a hundred miles or so!
as for bomber points, bigger payload, paid for with perks that you dont get back unless you bring the bombs back!