P-38

[Minotaur]

REFERENCE SITE

 

In level flight acceleration the F4U-4 gained speed at about 2.4 mph/sec, the P-51D accelerated at about 2.2 mph/sec. The F4U-1 could not keep up with either, accelerating at only 1.5 mph/sec. The real drag racer of American WWII fighters was the P-38L. It gained speed at 2.8 mph/sec. All acceleration data was compiled at 10-15,000 ft at Mil. power settings.

Turning to dive acceleration, we find the F4U-4 and Mustang in a near dead heat. Both the P-47D and P-38L easily out distance the Corsair and P-51D in a dive. Still, these two accelerate better than the opposition from Japan and Germany. Moreover, both the Corsair and the Mustang have relatively high critical Mach numbers allowing them to attain very high speeds in prolonged dives before running into compressibility difficulty. With the exception of early model P-38’s, it was almost always a mistake to attempt to evade American fighters by trying to dive away. This goes for early war fighters as well, such as the P-40 and F4F Wildcat

 

When we look at the turn rates of WWII fighters we stumble upon several factors that determine how well a fighter can turn. Aside from the technical aspects such as wing area and wing loading, we find that some fighters are far more maneuverable at low speeds than at higher velocities. This was very common with Japanese designs. At speeds above 250 mph, the A6M Zero and the Ki-43 Hayabusa (Oscar) could not roll worth a nickel. But at 150 mph, they were two of the most dangerous fighters ever to take wing. It did not take long for Allied pilots to learn to avoid low speed turning duels with the Japanese. Once this rule was established, the light weight dogfighters were hopelessly outclassed by the much faster opposition.

Over Europe, things were somewhat different. The Luftwaffe flew fast, heavily armed aircraft that were not especially suited to low speed turning fights. The Allies had in their inventory the Spitfire, which was very adept at turning fights. The Americans had the P-47, P-38 and P-51. All of which were very fast and at least a match for the German fighters in maneuverability. Especially the P-38 which could out-turn anything the Luftwaffe had and could give the Spitfire pilot pause to consider his own mortality. With the exception of these last two, there was nothing in western Europe that could hang with the F4U-4. Even when including the Soviets, only the Yak-3 could hope to survive a one on one with the Corsair. To do so, the Yak would have to expertly flown. Furthermore, the Yak-3 was strictly a low to medium altitude fighter. Above 20,000 ft its power dropped off rapidly, as did its maneuverability. The Yak-3 in question had better be powered by the Klimov M107A engine and not the low output M105. Otherwise, the speed difference is too great to overcome.

These quotes came from an article about the F4U-4.

I keep reading stuff like this over and over again.  For the AH P-38 this just ain't so.

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Mino
The Wrecking Crew

[Jinx]

I guess we’ll know soon, but I bet 1.02 will change a lot of the plane characteristics we are used to now, simply by fixing the flaps. The flower type flaps did all the difference in low speed handling on the planes that had them, by increasing wing area and giving it a hi lift profile. The P-38 is one that has among the most to gain, but the P-51 and the F4U will also be very different rides with maneuvering flaps giving better instant turn and in the case of the F4U much better low speed lift and handling. On something like the spit with a split flap that wasn’t much more then an airbrake the difference should be minimal.

Good post Mino.

  -Jinx

[funked]

Mino:

Acceleration of an aircraft in level flight varies greatly with altitude and speed.  So those numbers you quoted aren't particularly useful for comparison without more information on how they were obtained.

Just for kicks I thought I'd get some data on the same planes in Aces High.

So I took each plane up to 15,000 feet with maximum internal fuel and ammo.  I put the plane on autolevel, chopped the throttle, let the airspeed (true) decay to 150 mph, and firewalled the throttle - no WEP.  I recorded the time required to accelerate to 200, 250, 300, and 350 mph TAS.

Average acceleration in mph/second
P-51D, F4U-1D, P-38L
150-200 mph: 3.13, 3.85, 3.85
150-250 mph: 2.70, 3.03, 3.13
150-300 mph: 2.21, 2.34, 2.50
150-350 mph: 1.71, 1.56, 1.44

My time measurements were +/- 1 second, so I'll conservatively say these acceleration figures are within +/- 10%.

You'll note the P-38L is the fastest accelerator to 200 mph, 250 mph, and 300 mph.  Seems consistent with your source.  The F4U and P-51D have swapped positions at low speeds, but Aces High has a F4U-1D not an F4U-1.

The P-38L is the worst accelerator to 350 mph.  The P-38L can only do about 370 mph at this altitude in MIL power while the F4U-1D can do about 385 and the P-51D can do about 410.  So the P-38L is really running into the "brick wall" of drag at 350 mph and the acceleration suffers accordingly.

The turn rate issues are almost certainly due to the incorrect modeling of flaps in Aces High, so I am not going to bother analyzing it at this time.

I'll look at the dive acceleration next.

[Vermillion]

In my experience in Aces High, the P-38 is easily out turning the P-51, F4U, Fw190, and the 109G10.

No, it won't out turn a 109G2, 109F4, Spitfire, C.205, or a N1K2, but what do you expect, it literally weighs two and a half times as much.

And like Funked pointed out, it accelerates very nicely.

No the P-38 is not a good TnB fighter, but if flown strictly as a pure E Fighter, its deadly.  The biggest problem I have seen is that most people try to fly it like a Spitfire.

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Vermillion
**MOL**, Men of Leisure
Carpe Jugulum
"Real Men fly Radials, Nancy Boys fly Spitfires"

[Westy]

 What Verm said!

  BTW, I beleive that the flaps will be fixed in this next release but I also recall someone from HTC saying that the Fowler Flaps on the P-38 were not modelled at all yet.

 -Westy

[Citabria]

 www.zipit.com.org

[This message has been edited by Citabria (edited 04-05-2000).]

[Citabria]

knock knock...
who's there?
Zip it!


[This message has been edited by Citabria (edited 04-05-2000).]

[F4UDOA]

Minotaur,

I have also read that artical that highly praises the F4U-4 in comparison to the P-51D. However it seems to be written by an online amature. Really look at what he just said,
"P-38 easily out distancing the P-51D in a dive". Really? The P-51D critical mach number is so much lower that the P38's I highly doubt it. I have dive test results in "America's hundred thousand" that show the P-38 to be the third slowest behind the FM-2 and P61.
The P-38 was rated 1st however in initial
dive accelleration. Next was the F4U-1 and P-51D in a tie. This is a trusted souce of information however which is my point.
As for turn radius the P-38 should have an awful turn radius without the use of flaps.
It's wing loading is extremely high compared to Mustangs, Corsairs and especially Spitty's. Wingloading is weight divided by wing area. Pretty simple really. Also the wing of the P-38 was purpose built for range. It has  very narrow wing which is very long. Also known as a high aspect ratio wing.
It creates allot of lift but lacks the wing cord(width)to make low speed turns possible. It simply cannot displace enough air to keep flying. On the opposite side Naval A/C such as the Hellcat or Corsair had to handle well at low speeds so they had much lower wing loading. Shorter, wider wings that give good control at low speed. The Corsair was maligned as a Navy plane for poor handling IE. the Ensign Eliminator, was still better than it's army counter parts at low speed handling. By that I mean not only turn radius but aileron effectiveness and lateral control. The only army A/C that would have a better turn radius would be the P-63 which was not used by US Army forces in combat.  
Anyway if you would like to read a more acurate desciption of the P-38's performance pick up a copy of the "Report of joint fighter conferance" from 1944. It is a Schiffer publication and can be ordered from their web site http://www.schifferbooks.com
Things like take off runs and three G stall speeds are also mention in this book. Many of these dynamics are not currently modeled in AH.

Seeya
F4UDOA

[Citabria]

 www.zipit.com.org

[This message has been edited by Citabria (edited 04-05-2000).]

[Citabria]

 www.zipit.com.org

[This message has been edited by Citabria (edited 04-05-2000).]

[blur]

Just a heads up on this bird; I wouldn't get too attached to the flight model, as this may be another ufo brought back to earth.

The last time I flew the 38 it out-rolled the F-16 at 400 IAS and out-zoomed it too!    

Check out Pyro's comment in this thread:
<sorry link not working>

[This message has been edited by blur (edited 04-05-2000).]

[Citabria]

 www.zipit.com.org

[This message has been edited by Citabria (edited 04-05-2000).]

[blur]

I rechecked the post date of Pyro's message and discovered that AH ver. 101 patch 2 was released two hours afterwards. Let me check this bird out again, before I continue making a fool out of myself.  

[Vermillion]

Right now, except for the known flap issue with all the aircraft and what I say below, I think the P-38 is pretty damn close.

 

and exactly how can you possibly make the p38L worse than it is without making it totally unrealistic and absolutely nothing close to the performance of its RL counterpart?

How about giving it the initial roll inertia that is described in every pilots account ever written about the P-38?

I believe the roll rates are correct in the P-38 (sustained), but it doesnt' show the inertia that it should. This aircraft should be quite hard to get into a roll, but once you get it started be fairly fast. In other words there should be a slight hesitation when you begin a roll and especially when you change reverse a roll and then roll in that direction.

Thats just not true with the current FM. In my opinon, the N1K2-J has more roll inertia than the current 38 which is very wrong.


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Vermillion
**MOL**, Men of Leisure
Carpe Jugulum
"Real Men fly Radials, Nancy Boys fly Spitfires"

[wells]

Verm, check out the 205!  That has about the right roll inertia for a P-38.  

The 38 could *never* dive well, even with dive flaps (which only aided in recovery).  It's dive speed limit was 420 mph (440 MAX).  All the dive flaps did was allow it to dive at a 45 degree angle instead of a 15 degree angle!