HiTech no likes ponys?

[Grayeagle]

The biggest reason the Stang was faster than expected was due to the Laminar flow wing.
It has a lot less drag than the other designs of the era.
There were several smaller contributing factors ie: wing approx 90 degrees off the fuse, scoop exhaust providing thrust in some configurations, etc.

I had read somewhere that the fat leading edge of the Jug's wing worked very well at high AoA, giving the pilot definite feedback on just how close to stall he was hangin ..makin the Jug pilot confident in runnin her right up to the edge and holding her there.

The Mustang is .. different.
You get a mild stick shake at the borderline, any more back pressure and she departs.
Easy to miss in the heat of combat I expect.
I would imagine the first time the Stang departed on the new pilot probably scared the crap out of him if he wasn't expecting it, so he would not want to push it if he could help it.

Turn an burn wasn't American official procedure anyway
American iron was boom an zoom

-GE aka Frank

[Chalenge]

Reading up on drag divergence has me wondering what the mach numbers are on a P51 at 25k max speed and the same for an F4U? and drag coefficients also?

[BoilerDown]

Reading up on drag divergence has me wondering what the mach numbers are on a P51 at 25k max speed and the same for an F4U? and drag coefficients also?

Widewing made a few good posts a while ago about drag of the various airframes with respect to how far they will glide unpowered... would be worth searching for 'cause I think that information or some of it is in that post.  Of course they were ingame numbers, not IRL.

[BnZ]

Isn't really a problem in AHII. Got the horn going "eh" in your ear and every airplane in the game buffets before departure. Also, I think these turning tests are conducted with the stall limiter on to take skill at "riding the edge" out of the equation and give apples-to-apples comparisons.

The biggest reason the Stang was faster than expected was due to the Laminar flow wing.
It has a lot less drag than the other designs of the era.
There were several smaller contributing factors ie: wing approx 90 degrees off the fuse, scoop exhaust providing thrust in some configurations, etc.

I had read somewhere that the fat leading edge of the Jug's wing worked very well at high AoA, giving the pilot definite feedback on just how close to stall he was hangin ..makin the Jug pilot confident in runnin her right up to the edge and holding her there.

The Mustang is .. different.
You get a mild stick shake at the borderline, any more back pressure and she departs.
Easy to miss in the heat of combat I expect.
I would imagine the first time the Stang departed on the new pilot probably scared the crap out of him if he wasn't expecting it, so he would not want to push it if he could help it.

Turn an burn wasn't American official procedure anyway
American iron was boom an zoom

-GE aka Frank

[Chalenge]

I dont think the two instances (unpowered glide and rising mach) have much in common. I can see that the P51s laminar wing design would be a great benefit at high altitude and high speed. The F4U had its wing mated to the fuselage in such a way it didnt require a fillet to reduce parasitic drag. Both are good methods of holding drag to a minimum but in practice the P51s laminar wing was only 65% efficient at its purpose and the F4U had one of the worst cross sectional drag coefficients in the air! You can see this by looking at the two fuselage designs involved. The F4U has a nearly constant cross section while the P51 steadily decreases in cross section. As the aircraft approach (lets say) Mach 0.75 (both aircraft could attain this) the drag increases on the two airframes and the horsepower required to increase speed increases by a factor of ten (some sources say exponentially). The problem (I believe) is that the 'induced lift drag coefficient' in a turn slows planes down and for the P51 that induced drag should be only 35% of that for the F4U (because the F4U will induce substantially more drag owing to the fact it does not have laminar flow and the reason the F4U needed so much power to begin with) giving the pony a significant advantage in turn performance at high altitude and high speeds. I am admittedly not well informed on this topic but that is what I am reading seems to be telling me.

I really would like to hear from someone (anyone) that truly understands this.

EDIT: Man! Took me nearly an hour in editing to get any of that to make sense! 

[BnZ]

Mach .75 is well over 500mph TAS at 20K feet.

IOW, territory you have to enter a dive to reach in the first place. Not a corner of the envelope I am excessively concerned with Chalenge :-)

Oh, btw, the reason I mentioned the Corsair earlier in a comparison is, because (If I remember correctly, it has been awhile), the P-51's airfoil actually has a slightly higher Cl-max, IOW, it should actually produce a bit more lift and turn a bit better in relation to its wing-loading than does the Corsair, once again, leaving the Corsair's flaps out of the equation.

I dont think the two instances (unpowered glide and rising mach) have much in common. I can see that the P51s laminar wing design would be a great benefit at high altitude and high speed. The F4U had its wing mated to the fuselage in such a way it didnt require a fillet to reduce parasitic drag. Both are good methods of holding drag to a minimum but in practice the P51s laminar wing was only 65% efficient at its purpose and the F4U had one of the worst cross sectional drag coefficients in the air! You can see this by looking at the two fuselage designs involved. The F4U has a nearly constant cross section while the P51 steadily decreases in cross section. As the aircraft approach (lets say) Mach 0.75 (both aircraft could attain this) the drag increases on the two airframes and the horsepower required to increase speed increases by a factor of ten (some sources say exponentially). The problem (I believe) is that the 'induced lift drag coefficient' in a turn slows planes down and for the P51 that induced drag should be only 35% of that for the F4U (because the F4U will induce substantially more drag owing to the fact it does not have laminar flow and the reason the F4U needed so much power to begin with) giving the pony a significant advantage in turn performance at high altitude and high speeds. I am admittedly not well informed on this topic but that is what I am reading seems to be telling me.

I really would like to hear from someone (anyone) that truly understands this.

EDIT: Man! Took me nearly an hour in editing to get any of that to make sense! 

[Chalenge]

Mach .75 is well over 500mph TAS at 20K feet.

IOW, territory you have to enter a dive to reach in the first place. Not a corner of the envelope I am excessively concerned with Chalenge :-)

Oh, btw, the reason I mentioned the Corsair earlier in a comparison is, because (If I remember correctly, it has been awhile), the P-51's airfoil actually has a slightly higher Cl-max, IOW, it should actually produce a bit more lift and turn a bit better in relation to its wing-loading than does the Corsair, once again, leaving the Corsair's flaps out of the equation.

Sorry to say it BnZ (not really) but I didnt ask the question because of your 'excessive concerns.'  I believe the P51D was designed for advantages above 12k and not down in the mud. If you like it low you should fly the Tempest (now there is a plane that is excessively modelled!).

Mach 0.75 at 25000 feet is 520mph and at that altitude you dont have to do a lot of diving to get that kind of speed.

I asked the question because I fly that altitude often enough to have seen a few things you probably havent like F4Us running off and leaving a P51 in a dive when the P51 is compressed and the F4U isnt. I dont think thats accurate but please cite a book or other reference if you have it stating differently. Also you might note that the speed I mentioned was an example given because of compressibility issues and I would like to know the limits (mach) for a Corsair (a real one). I know the P51 can enter 0.78 Mach with the wing design of 1944-45 (the edge of compressibility) and I know the laminar flow wing should present advantages in performance and efficiency at high altitude manuevering and yet I dont see it and therefore the questions.

[SectorNine50]

Did the P-51 have boosted control surfaces?  I know the F4U did...

[BnZ]

Sorry to say it BnZ (not really) but I didnt ask the question because of your 'excessive concerns.'  I believe the P51D was designed for advantages above 12k and not down in the mud. If you like it low you should fly the Tempest (now there is a plane that is excessively modelled!).

Well, you know, it was ORIGINALLY designed to be a low-altitude, high-speed attack plane to replace the P-40s the Brits were using in that role.

And the P-51D has an engine tuned for lower altitude performance than the B model. In no small part because by late in the war, the drive to fly the bombers in ever-higher had abated somewhat and also more fighters were being used for a mud-moving role in the final push on Hitler's Germany.

I'm not saying your research isn't interesting, I'm just saying that right now I'd be more concerned that the AHII P-51D can not turn as well as a P-47D-11 or that a 190-D9 can actually make a smaller circle with full flaps. 

[Widewing]

Did the P-51 have boosted control surfaces?  I know the F4U did...

The F4U did not have boosted control surfaces. From the P-38J-25 on, Lightnings were the only fighter with hydraulically boosted controls surfaces and that was limited to the ailerons only.


My regards,

Widewing

[Old Sport]

The F4U did not have boosted control surfaces.

While not hydraulically boosted, it appears to me that F4U ailerons did have a clever tab system slaved to the stick that, I would guess, was specifically incorporated to reduce aileron stick pressure and help roll rate. I noticed this on the AH F4Us after the last F4U update. You can see a small tab on the inboard end of each aileron that is distinct from the single trim tab in the middle of the port aileron. The deflection of the two smaller tabs is directly proportional to the throw of the stick. Not a bad idea if that's what it really is.

 

[Chalenge]

Well, you know, it was ORIGINALLY designed to be a low-altitude, high-speed attack plane to replace the P-40s the Brits were using in that role.

And the P-51D has an engine tuned for lower altitude performance than the B model. In no small part because by late in the war, the drive to fly the bombers in ever-higher had abated somewhat and also more fighters were being used for a mud-moving role in the final push on Hitler's Germany.

I'm not saying your research isn't interesting, I'm just saying that right now I'd be more concerned that the AHII P-51D can not turn as well as a P-47D-11 or that a 190-D9 can actually make a smaller circle with full flaps. 

I am well aware that the earlier Mustang (with an Allison engine) was designed for low altitude. You are mistaken about the D model though as 'ever-higher' altitudes is precisely what the D model was for and that statement was a ridiculous comment. Like you though if the P51 is in anyway modelled incorrectly I would like it fixed.

[BnZ]

I am well aware that the earlier Mustang (with an Allison engine) was designed for low altitude. You are mistaken about the D model though as 'ever-higher' altitudes is precisely what the D model was for and that statement was a ridiculous comment. Like you though if the P51 is in anyway modelled incorrectly I would like it fixed.

Ummm, have you actually checked the speed and climb rates of our Dstang vs. our Bstang at altitudes above 20K?

[Tr1gg22]

Riiiight,, you are the king of all pony pilots.  You don't have to like it, but the tiff and tempy out turn the pony.  The data is irrefutable. I made no mention of a difference in pilot skill.

    I guess if a guy stays in a flat turn because he don't no how to do anything else...I just never thought they out turned the pony. I don't think they do enough to make much of a difference..Unless ur in a stalling flat turn<<< noob turn

[uptown]

there's not much a mustangs can out turn  This chart does not represent what i see in the game. The P38 will eat a pony up in a turn fight. But according to this the pony out turns the J & L models. Charts and stats are one thing and game performance is another. The P51D works best for me between 8 and 12K and seems very unresponsive at 15K and above. I was always under the impression the the P51D was a high alt dog fighter.