F4UDOA: P-38L weight. performance

[Citabria]

P-38L

12,780lbs empty (5797kg)

this may or may not include the weight of the 4 nose mounted 50 cal machine guns and the single 20mm cannon (no ammo)total weight of the MG's and cannon was 621lbs
combat loaded weight of the P-38L is listed at 17,400lbs

the P-38L has internal fuel capacity of 416 gallons x 6 lbs/gal for 2496lbs of fuel. contained in 6 tanks (2 outer wing, aux tanks front inner wing , main tanks rear inner wing)
12,780 + 2496 = 15,276lbs

normal ammo load wieghed 712 lbs not including ammo chain links (C. Jordan)
(800 rds 50cal 150 rds 20mm)
15,276 + 712 = 15,988lbs

the p-38L V-17010f-30 engines each had a 13gal oil capacity. 23 x 6 = 138lbs
15,988 + 138 = 16,126lbs

that leaves 1274 lbs for the pilot and ammo links or even the max ammo load (an aditional 1200rds of 50cal) if you use 17,400lbs as the standard weight for a p-38L with no external load


the wieght of the P-38L with 50% internal fuel using 17,400lbs as standard loaded it is:
17,400 - 1230 = 16,170lbs

here is the data I found from C.C. Jordan's lengthy discussion on the merits of the P-38L: http://yarchive.net/mil/p38.html
The basic performance figures for the P-38L are as follows (from Lockheed
factory test logbooks):
Max speed at sea level: 352 mph
Max speed at 5,500 ft : 369 mph
Max speed at 23,500 ft. 440 mph (WEP)
Max speed at critical alt: 444 mph @ 25,800 (WEP)
Max climb rate at sea level: 4,225 fpm (50% fuel, normal ammo)
Time to 23,400 ft: 5.94 minutes
Time to 30,000 ft: 8.86 minutes
Service Ceiling: 44,000 ft.

Allison V-1710F-30 was the most powerful engine used on the L model P-38. 1725hp vs the 1600hp of earlier engines
The following are the CORRECT stats for the Allison V-1710F-30.
Ratings___ [minutes]_ Power_ RPM___Manifold[in.Hg]_Altitude [ft]
Normal___ (no limit)___1,100___2,600____44_______30,000
Take Off____(5)______1,475___3,000____54________SL
Military____(15)______1,475___3,000____54_______30,000
WEP_______(5)_______1,725___3,000____60_______28,700


P-38G  345 mph @ 5,000 ft. / 402 mph @ 25,000 ft.(METO) / Climb: 2,885 fpm.avg.
P-38H  352 mph @ 5,000 ft. / 409 mph @ 22,000 ft.(METO) / Climb: 3,070 fpm.avg.
P-38J   360 mph @ 5,000 ft. / 421 mph @ 22,500 ft.(METO) / Climb: 3,585 fpm.avg.
P-38L   365 mph @ 5,000 ft. / 442 mph @ 22,500 ft. (WEP) / Climb: 3,750 fpm.avg.

[This message has been edited by Citabria (edited 01-15-2001).]

[Jimdandy]

Cit your a P-38 mad man.   You have flogged the disbelievers with your last few posts.

[Citabria]

 P-38 stall from the flight manual:
With power off., the airplane stalls at the following air speeds and gross weights noted.

______________________15,000lbs__17,000lbs__19.000lbs
Flaps and landing gear up__ 94 mph___100 mph____105 mph
Flaps and landing gear DOWN 69 mph___74 mph____78 mph


b. As stalling speed is approached, the centre section stalls first with noticeable shaking of the airplane, however the ailerons remain effective.
c. In either power ON or power OFF stalls with flaps and landing gear up the airplane rushes straight forward in a well controlled stall. With flaps and landing gear down there appears to be a slight tendency for one wing to drop. There is however no tendency to spin. Under these conditions, the nose drops slightly and as the speed increases, the wing will come up.

more on climb performance:
The USAAF did a great deal of testing with every variant of the P-38. Most of
the data generated is available through the USAF Historical Research Center.
This requires one to travel there and perform a search. You can usually hire a
student to do your research if you don't mind parting with some green stuff.

The following climb figures appear in various test documents from several
different test facilities.

Time to height:
P-38F from sea level to 10,000 ft at 48 in. Hg. MAP, 2,900 rpm: 3.56 min.
P-38F from brake release to 10,000 ft.: 4 min, 35 sec.
P-38J sea level to 23,800 ft, 60 in. Hg. MAP, 3,000 rpm: 6.19 min., still
maintaining 2,900 fpm at that altitude.
P-38L sea level to 20,000 ft. 60 in. Hg. MAP, 3,000 rpm: 4.91min, still
maintaining 3,450 fpm at that altitude.

[This message has been edited by Citabria (edited 01-15-2001).]

[Citabria]

and here is how the Aces High P-38L performs

P-38L loadout:
100% fuel
200rpg 50cal, 150rds 20mm
no external ordnance

top speeds wep/mil 1.04 AH P-38L vs AH chart

30k 400wep, 385 (chart 405wep, 390)
25k 415wep, 390 (chart 415wep, 400)
20k 395wep, 385 (chart 403wep, 388)
15k 385wep, 370 (chart 387wep, 372)
10k 370wep, 360 (chart 374wep, 360)
05k 355wep, 345 (chart 357wep, 345)
00k 345wep, 330 (chart 345wep, 332)


time to climb, feet per minute, mil power
01k 0:18 3333
02k 0:37 3158
03k 0:56 3158
04k 1:15 3158
05k 1:35 3000 4-6k avg: 3053 chart 3200
06k 1:55 3000
07k 2:14 3158
08k 2:35 2857
09k 2:55 3000
10k 3:16 2857 9-11k avg: 2952 chart 3050
11k 3:36 3000
12k 3:58 2727
13k 4:20 2727
14k 4:42 2727
15k 5:05 2609 14-16k avg: 2648 chart 2850
16k 5:28 2609
17k 5:51 2609
18k 6:15 2500
19k 6:40 2400
20k 7:05 2400 19-21k avg: 2369 chart 2600
21k 7:31 2307
22k 7:58 2222
23k 8:25 2222
24k 8:53 2069
25k 9:22 2069 24-26k avg: 2024 chart 2300
26k 9:53 1935
27k10:25 1875
28k11:01 1667
28k11:40 1538
30k12:23 1395 29-31k avg: 1394 chart 1700
31k13:11 1250

time to climb, feet per minute, WEP
01k 0:17 3529
02k 0:34 3529
03k 0:50 3750
04k 1:07 3529
05k 1:24 3529   4-6k avg: 3529 chart 3700
06k 1:41 3529
07k 1:58 3529
08k 2:15 3529
09k 2:32 3529
10k 2:50 3333  9-11k avg: 3398chart 3500
11k 3:08 3333
12k 3:27 3158
13k 3:46 3158
14k 4:06 3000
15k 4:26 3000 14-16k avg: 3000 chart 3200
16k 4:46 3000
17k 5:07 2857
18k 5:28 2857
19k 5:50 2727
20k 6:13 2609  19-21k avg: 2648 chart 2800
21k 6:36 2609
22k 7:00 2500
23k 7:25 2400
24k 7:51 2308
25k 8:19 2143 24-26k avg: 2150 chart 2350
26k 8:49 2000
27k 9:21 1875
28k 9:55 1765
29k10:33 1579
30k11:15 1428 29-31k avg: 1428 chart 1700
31k12:02 1276


[This message has been edited by Citabria (edited 01-14-2001).]

[Citabria]

here is a climb test to 20k for the 1.05 P-38L

test specifications:
1x fuel burn
P-38L
50% fuel
normal ammo load (800rds 50cal 150 rds 20mm)
WEP from begining of climb until wep expires (5 min and 20 seconds)

1:16 (1.26)5000feet. average climb 0-5k: 3947fpm
2:34 (2.56)10,000feet average climb 5-10k: 3846fpm
4:04 (4.06)15,000feet average climb 10-15k: 3333fpm
5:35 (5.58)20,000feet average climb 15-20k: 3289fpm

climb rate at 20k WEP: 3100fpm. best climb speed found at about 170mph

fuel remaining at 20k: 50%main 25% aux tanks

[This message has been edited by Citabria (edited 01-14-2001).]

[Zigrat]

great post, id like to hear pyro's input on it

great post on gyroscopic forces on the airplane too

>

[Jimdandy]

Flog'um Cit! Beat them with the facts.   38 lover's unite! "Come together right now over Cit..."

[Tac]

*raises his lighter in the darkness*

[Jimdandy]

 

Originally posted by Tac:
*raises his lighter in the darkness*

"Cit was a school boy when he seen his first 38 spec..."

[214thCavalier]

Cit you may have already seen them but i have some Take off, climb and Landing charts for the P38H, J and L dated DEC 1942/43 as best i can make out.
They give take off weights and distance to clear 50ft required for 3 diff weight configs on 3 different airfield surfaces.
Climb data for 3 diff weights under 2 diff power settings IE combat and ferry and the engine settings used.
Best IAS in knots and mph for climb at 5 k intervals up to 35k inc  FPM and time to climb, altho that is to the minute no seconds.
It also shows the fuel used to each altitude in IMP and US gallons.
And to finish 2 diff landing weights with best IAS approach speeds onto 3 different airfield surface types and for sea level , 3000ft and 6000ft altitude airfields.
If your interested i shall post em up but as they total about 600k for 3 pages after i have reduced colours and compressed em trying to keep em readable i was reluctant to post em unless you actually wanna see em.
I also have similar for the P51 and P47 carrying different ordnance configs.
I reckon you have all probably already seen them tho so unless you ask i shall not waste my web space.

[Citabria]

post em please

[Citabria]

hats off to pyro. he does a hell of a job

it's been quite an enlightening experience trying to sort out whats accurate information for a 60 year old airplane.

still it sure is fun looking at this stuff.        
hope you guys enjoyed it too.


the most intriguing part for me is this information about 1725hp engines on the P-38L's and the somewhat astounding 440mph  max speed said to be atainable by the P-38L

there seems to be controversy over these numbers saying that the P-38L was capable of 440mph with the WEP 1725hp engines and that the speeds and climbs were well documented by the USAAF. these records still exist at the USAF Historical Research Center  at maxwell AFB in Alabama says C. Jordan. but to actually prove it would require a little field trip.      

 http://www.maxwell.af.mil/au/afhra/

did late model P-38L's have 1725hp engines as he says?
how many versions of the P-38L were there? I know of the P38L-5 and P-38L-10 but is there more?

is the low altitude performance of 152mph at sea level vs 145mph at sea level for the P-38L is less of a controversy and it seems perfectly reasonable that the additional 250hp of the v-1710f-30 engines would surely give the L-model this increased deck speed?

how many licks does it take to get to the center of a tootsie roll pop? the world may never know.


[This message has been edited by Citabria (edited 01-15-2001).]

[wells]

Cit,

That 1725 hp number does look a little fishy in the context of 60" of manifold pressure.  If that were the case, it would be shown in the pilot's manual as such.  Given that power is almost a direct function of manifold pressure and rpm, it doesn't make sense (it's too high) when compared to other power outputs for MIL or max continous.  However, later Allison's (143/145), such as on the P-82 were cleared to 65" Hg (dry) on 100/130 fuel, which would make that 1725 hp figure look a lot more realistic.  The only other thing I can think of is that when that particular test was done, it was a cold day and the results were not corrected to standard pressure and temperature.  Maybe someone should contact C. Jordan and see if he has any of those original test documents he quotes from?  

[flakbait]

I found these on Zeno's page. He's got more about the P-38L, but this is the interesting stuff.


 

 

Note that it states under War Emergency "60" for manifold pressure. Military looks like 54", and takeoff looks like 50".


-----------------------
Flakbait
Delta 6's Flight School
"For yay did the sky darken, and split open and spew forth fire, and
through the smoke rode the Four Wurgers of the Apocalypse.
And on their canopies was tattooed the number of the Beast, and the
number was 190." Jedi, Verse Five, Capter Two, The Book of Dweeb
 

[Citabria]

its possible they were running beyond published limits at 65"mp like you said on the L but thats just speculation.

I emailed him about the info he posted.
 I sure would like to get a hold of the original test data.