P-38

[Vila]

Hmmm Wells, I could be wrong.... BUT...

MY 38 manaul says that the dive flaps should be deployed when entering a dive... seems like thye were used to improve airflow over the elevator and NOT just to initiate a recovery...  Also, the dive angle limits are inidicated for a "sustained" dive... whatever that means.  Also, is it just me, or is it HARD to slow down in a gentle, idle throttle dive, harder than I thought it "should" be... that means many planes (including the 38) reach structural limits on speed rather faster (and at shallower angles) than they "should".  Note I put should in " "'s since it's based on my relatively uniformed opinion.  What's ur take on the low AOA, low power setting drag characteristics?

Vila

[Wraith]

Funked, I dont know how you got those numbers buddy, but I've flown side by side with wingmen flying the pony and spit and F4, we both take off at the same time (side by side), we leveled at 10 k, matched speeds (150), then went full throttle (mil). Spit and pony leave the 38 eating their dust after a 30 second level flight. Quite hard to picture    


"Also, the dive angle limits are inidicated for a "sustained" dive... whatever that means"

Means your plane wont gain as much speed, allowing time to position the plane, aim and fire the AG ordenance AND allowing pilot to level again without becoming a lawn dart or losing the wings    

I agree on the roll characteristic.. it should be hard to start a roll on the 38. Just like in Aces of the Pacific (yeah! Sue me, but I LOVED the 38 model in there hehe)

I just wish we could paint the 38 in a greenish color..that white is just too easy to aim for    

BTW, from the same site, take a look at this SAD story in the history of the P-38: http://home.att.net/~C.C.Jordan/P-38K.html

Just to give you a taste of what's in there:

 

The Best Performing Variant Of The P-38 Lightning

 

What astounded the evaluation team was the incredible rate of climb demonstrated by the P-38K. From a standing start on the runway, the aircraft could take off and climb to 20,000 feet in 5 minutes flat! The "K", fully loaded, had an initial rate of climb of 4,800 fpm in Military Power. In War Emergency Power, over 5,000 fpm was predicted.

DAMN PENCILNECKS!!!  

Also, for some GREAT reading regarding the experiences of P-38 pilots and pilots who flew against the P-38 and some misc info on the plane's performance, history and other, read this 3-page long beauty:
 http://home.att.net/~ww2aviation/P-38.html

BTW, in that document they say "The P- 38 was the only US fighter capable of engaging the Bf109G and Fw190A on equal terms"

Ooooh.. I'd love to see that here  

Enjoy!

Citbria: Send me an e-mail buddy, im in Orlando too!



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

[Vermillion]

Vila, Right now there is no Prop drag in the game for any of the aircraft.

Thats why you have such a problem slowing down in idle shallow descents.

This makes some aircraft quite hard to land, including the P-38.

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

[F4UDOA]

Hmm,

I was doing some roll testing offline when I suddenly discovered my problem.

 

Oops

[Tern]

 

Originally posted by F4UDOA:
Hmm,

I was doing some roll testing offline when I suddenly discovered my problem.

 
Oops

FOCLMAO! That's great!  IS there a link with more of these on it?  

------------------
Tern
"Live to Fly!  Fly to Fight!  Fight to Live!"
========================
"There I was, inverted at 50 feet and 120 kts. and the only thing running was the radio."

[Citabria]

currently if the rpm gauge is accurate the p38 is only capable of 2,700rpms.


The two Allison V-1710F-30 V-12s had a 5.5 in. bore and 6.0 in stroke, providing a compression ratio of 6.5. These drove Curtiss Electric constant speed props via a 2:1 reduction gear, delivering 1,475 HP military and takeoff ratings at 3,000 RPM, or 1,612 HP maximum rating at 3,000 RPM and 60 in. of manifold pressure. Some later engines are described as delivering up to 1,725 HP WEP rating. The engines required 100 octane or higher rated fuel, and had 13 USG oil capacity. The oil was cooled in two outboard chin core radiators, vented via automatically controlled flaps on either side of the nacelle. Fuel consumption was 0.65 lb/HP./hr at 1,100 HP normal rating, at 2,600 RPM.


who was that saying the p38 is underpowered?

you guys wanna tear it up in the name of accuracy I can find stuff to make it better in the name of accuracy.


either way, you will see me flying it    


"Every one of these problems was solved with the introduction of the P-38L."

"Let me repeat this again and again. It can never be emphasized too strongly. It makes up the Gospel Word. The P-38L. Now there was the airplane."

"Nothing, to these pilots, after the hard winter of 1943-44 could be more beautiful than a P-38L outrolling and tailgating a German fighter straight down, following a spin or split-S or whatever gyration a startled, panicked and doomed German might attempt to initiate. You just couldn't get away from the P-38L. Whatever the German could do, the American in the P-38L could do better." (cited from [8] with permission from Arthur W. Heiden).


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

[wells]

Vila, a 15 degree dive angle on a 17500 lbs airframe makes for an additional 4500 lbs of thrust.  This is the angle where the dive speed limit can be sustained.  Any more and it wants to accelerate and any less it will slow down.  True, there is no prop drag at the moment, so pulling back to idle doesn't help.  

The math...

Thrust at 340 mph = 2800 lbs (80% prop efficiency assumed)

V2 = sr(4500/2800) * 340
= 430 mph

The dive flaps would deflect the airflow down, making for lower pressure under the stab (the nose goes up) as well as adding a lot of drag beyond the Mach divergence speed.  It has been discussed that those little flaps wouldn't add much drag, but if you consider that air has to flow 'around' them, the local Mach no. could be very much higher, creating TONS more drag than they would at lower speeds.

[funked]

Wraith, my test was at 15k not 10k.  The engine power of the P-51D is much less at 15k than at 10k, while the P-38L has the same power available at both altitudes.  That's most likely the reason for the discrepancy in our results.

Also when you do a "head to head" test like you described, net lag makes it impossible for both pilots to move the throttles at exactly the same time.  So that method is not as accurate as using a stopwatch.

Finally I didn't include the Spitfire Mk. IX because I don't have any real-life figures on its acceleration vs. that of the P-38L.  Given the Spitfire Mk. IX's much superior power to weight ratio, it should leave both the P-38L and the P-51D in the dust.

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

[Wraith]

 

The P-38 would go on to be the dominant fighter aircraft in the MTO until it’s gradual replacement by the P-51 beginning in mid 1944. The Lightnings were not replaced because the Mustang was superior. The replacement was one based upon economy. The Mustang was far cheaper to manufacture, and with only a single engine, was far easier to maintain as well. In terms of performance, The P-51 exceeded the Lightning in only one area: Maximum speed, and only between 22,000 and 27,000 feet. At nearly every other altitude the P-38 had the edge. Especially later variants with revised intercoolers. The Lightning, in particular, the P-38L (the largest production run model) was equal or even superior in every other area of performance. It is not unusual to find that a significant number of pilots who flew both in combat, would choose the P-38 over the Mustang as a dogfighter. Der gabelschwanz teufel, indeed.

http://home.att.net/~C.C.Jordan/P-38MTO.html

Heehee.. rub the salt in the wound runstangs!  

[F4UDOA]

Ok I won't ask you to believe me but would you beleive the actual combat pilots that decided the future of A/C design in 1944.
This data is specific to the P-38L in January of 1944. Quoting from "The report of joint fighter conferance". First there are many catagories these A/C are rated in but since I do not wish to type all night I'll give you the ones relavent to this thread.

First the A/C was tested by 28 pilots
1 Army, 9 Navy, 5 British and 13 contractor
"Combat Qualties" 3 good, 0 fair, 1 poor,
15 other, and 9 blank.
Bad visibility to sides and down. Would rather fight have F6F or F4U for Pacific-1.
I would not consider this a modern fighting A/C. Poor coordination of control forces and effectiveness, combined with very weak directional stability make it a poor gun platform, and its manuverabilty rating is so low that it precludes its use in modern combat-1. As a fighter bomber good , for fighter sweep just fair as for escort poor-1.
Good due to 1. twin engine reliabilty 2. high altitude performance 3. good accelerated stall 4. versitilty 5. dive flaps that make prolonged zero lift dives possible-1.
Apart from very quer ailerons the A/C is quite plesant to fly, and would probably make a very good strike fighter. There is an objectionable wobble in bumpy air-1. An excellent escort fighter . Speed should be sufficient for most present day Jap fighters. View is poor, too many struts in the way. Rudder makes A/C very hard to manuver on first flight-1. Too complicated and full of gadgets, would make unservicablity very high-1. Query on maintanence and operational problems with liquid cooled engines in hot climate.-1. To much mechanical equipment for one man to operate in combat-1. Record speaks for itself-1.

Maneuverabilty-rating A for excellent, B for good, C for fair  and D for poor. 28 pilots
A-2 B-10, C-13, D-1, blank-2

Stall test. In IAS MPH, 28 pilots
Clean power off-90 Clean Power on-100
Range-80-95         Range-95-115
Landing condition
Power off-80       Power on-84
Range 70-98        range 75-100
Accelerated 3G stall 170 No range given

Rating versus other A/C 9-Army, 15-Navy 7-British 20-contractor(including Lockeed)
Best Stabilty and control in a dive.
F4U-1D-25%         P-51D-10%     Mosquito-3%
P-47D-25 23%       F8F-4%        FM-2-2%
F6F-5-13%          P-63-4%       P-38L-2%
F7F-11%            P-61-3%


Best Fighter above 25,000Ft
P-47D-25-45%   F6F-5-3%     P-38L-1%
P-51D-39%      F4U-4-3%
F4U-1D-7%      Seafire-2%


Best fighter below 25,000ft
F8F-30%     F7F-6%       F4U-4-2%
P-51D-29%   F6F-5-2%     F2G-2%
F4U-1D-27%  Mosquito-2%


The P-38L is not mentioned in the above Catagory???? Meaning the Lockeed pilots did not vote for it.

Some A/C were not flown by all pilots because of security restrictions. IE. the F8F, F7F, F4U-4, F2G, and P-47M. This relects in the voting or lack of votes for upgraded or new A/C.

I really don't want to type the whole book tonight if I can help it, but my point is that the P-38L was not an Uber plane. At least not by US military specs in 1944 compared to other fighter A/C in use. IE. P-51D, F4U-1D or P-47D-25. In any case it was not awful either. And if you want to argue this flight test data you better bring a shovel because most of these gentleman aren't available for comment at this time.

Thanks F4UDOA  

[This message has been edited by F4UDOA (edited 04-05-2000).]

[This message has been edited by F4UDOA (edited 04-05-2000).]

[Citabria]

"Too complicated and full of gadgets"
that says it all.

Did they ask Bong, McGuire, Macdonald? or any other top scoring p38 ace? or even any fighter pilot with much multi time?
guys who had a lot of time in the p38 and knew it through and through? or just a bunch a rookies to see which one they liked?


I have your data and here is a comparision between it and the AH P38L

real P38L
stall power off 80-95mph variable with weight
stall power on 90-115
(I assume flaps up)

landing configuration:
(flaps down wheels down)
stall power off: 70-98mph
stall power on: 75-100mph


note... turn the Aces High p38L inverted and stall it... thats whats sposed to happen. nose plops down. yes it was that stable in a stall a veritable cessna with "all that inertia"

why did McGuire snaproll then you say?
lets see he was turning with (not to mention staying with) a ki43 no doubt using differential throttle flaps, rudders and in a steep turn what do you think?
and any plane.. even a citabria can snap roll and do it well in spite of stability in a stall and the nose ability to point from up to straight down without a wing dropping.

so the stall speed is to high on the AH P38L 120 power off and 120+ power on so we get the off side power on and way off side power off and we havent been able to test flap stall yet but its 120+ with them down as is.

accelerated stall in AH p38L is horendous you can be at 200mph and torque out like a 51.

AH p38L dives are not "prolonged" a good steep dive and you hit 550mph and fall apart while the real 38L had to be almost supersonic to break up.


the p38L only locked up after 480mph. currently hits 400 and its a 109 as far as control lockup.

AH p38L... I wish I could remember all the shots I missed due to slow initial roll regardless of how fast I was rolling after i got moving it was to late. I have no qualms with this being to grimly modelled.


they scrapped it for its high cost and high maintnence. the bottom line is always the bottom line even in fighter procurement.

why get 1 p38 when you can get 2 p51s for 1 1/3 the cost?

give me some more Hard Data by all means and I'll tell you what the Aces High p38 does compared to it    


[This message has been edited by Citabria (edited 04-06-2000).]

[Vermillion]

 

AH p38L dives are not "prolonged" a good steep dive and you hit 550mph and fall apart while the real 38L had to be almost supersonic to break up.

the p38L only locked up after 480mph. currently hits 400 and its a 109 as far as control lockup.

Well, this is not what the P-38 Pilots Manual says. The Do Not Exceed Dive speeds for the P-38 are between 420-440 mph depending on altitude. And even with the dive brakes extended prior to the dive, it states that the dive limits may only be exceeded by a maximum of +40mph. Oh and the AH model doesn't have dive brakes yet, so the 420-440 number is correct.

And next time you are "breaking up" at 550mph IAS, check the litle red slash on the speed gauge. You may find that your actually speed (TAS) is approaching the mach limit.

 

AH p38L... I wish I could remember all the shots I missed due to slow initial roll regardless of how fast I was rolling after i got moving it was to late. I have no qualms with this being to grimly modelled.

Good (admittedly bad for you), thats the way the P-38 SHOULD fly, and was one of its classic weaknesses.   And if anything the roll inertia is way too low, it still has an initial roll rate much better than several single engine models.

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

[This message has been edited by Vermillion (edited 04-06-2000).]

[juzz]

With the current version of AH you can still go supersonic, I think. I did it in the Me 109F iirc.

[Citabria]

pilot manual for what model p38L?

the P38J could not exceed those speeds without severe nose tuck and compression

[funked]

Compressibility is not modeled in the sim yet.  When it comes there is going to be a day of reckoning.  No more supersonic cannon spray monkeys woohoo!