P-38J-L questions.

[bolillo_loco]

Hi just found this place. I have some questions that have never made sense to me about this plane and I was hoping that somebody could clear them up for me.

top speed of the lightning seems to come from americas hundred thousands data. also the rates for climb. this data is the lowest I have seen, but not too far from other books I have.

martin caidin's book

speed in tas

360 mph 5,000ft
390 mph 15,000ft
421 mph 25,000ft
426 mph 30,000ft

rate of climb fpm

3,900 at 5,000ft
3,600 at 15,000ft
3,100 at 25,000ft

warren bodies book says

345 mph sea level
421.5 mph at 25,800ft
4,000 fpm at sea level
2,900 fpm at 23,400ft
6.19 minutes to 23,400 ft

this book also goes on to describe that the last half of 38Ls had 1,725 hp wep vs 1,600 of earlier Js and Ls top speed is listed as 425 military and 440 wep.

dive speeds. I see the 460 mph figure is used. is this in tas or ias. 420 mph ias at 10,000 ft is listed in the pilots manual, but this is with out the dive recovery flaps being used. with them it says you can safely exceed this number by 20 mph.

these speeds do not represent the true ias that the plane was doing. the speedo had large errors. how come mach speeds which are more accurate arent being used?

this data is listed for max mach number permitted with out dive recovery flaps.

mach .675 buffet begins
mach .72 nose becomes heavy
mach .74 nose tucks under

I have three books which all agree on one thing. mach .72 was safe in a lightning with dive recovery flaps.

the g limits is another question I have. I saw the g limit is listed as 6. this is a bit low. 38s were rated the same as 47s 8g work load and 12g break. the mustang is listed a bit higher than it should. remember the original P-51A was stressed for 8g work and 12g break, but it was also much lighter than a P-51D, but used the same airframe.

one more question. I dont buy the 400mph figure of a 38 at 30,000ft. consider this. a P-38J/L did 390 mph TAS at 30,000ft under 2,200hp (max cont power) they made wep power to 29,000ft so with 1,000 more hp the lightning only picked up 10 mph? it just doesnt seem to jive with other planes that picked up 25-40 mph with just 200 hp additions. I understand that a 38 is big, but still 1,000 more hp only gives it 10 more mph?

[This message has been edited by bolillo_loco (edited 12-08-2000).]

[bolillo_loco]

oh one more question. I do not have this game yet, but was thinking of getting it. does the 38 spin when stalled at any speed while both engines are running normaly?

[Sancho]

I fly the jug pretty much exclusively, so I can't answer your question.  But why don't you download it and test yourself?  The software is free to download and play offline.

[GRUNHERZ]

BOLILLO! Welcome to AH bud. Are you gonna sign up to fly here, or just stopping by?

[LLv34_Snefens]

Hi Bolillo_Loco and welcome to AH.

I can't comment on the speeds other than the planes in the game seems to follow the numbers the graphs are showing.

As for the max dive-speeds and G-loadings these shouldn't be taken as "exeed this and you are doomed"-numbers. They are more of a guidance to be careful when exceeding them.

I think the divespeeds listed are IAS. Reason they are not mach is that this number can't be read from the cockpit. We only got IAS (the white needle) and TAS (The red marker. Unhistoric of course)
I just tried the P38L, and from put it in a dive from 30,000ft. Surely the nose began to tuck under, but when I reached 525mph TAS at I deployed the dive-flaps and the nose came back up. From about 20,000ft I tried another dive and this time I reached 625mph TAS. The airframe moaned and groaned, (think it started at about 475 IAS), but it didn't break.

As for the G-limits it can also easily go above the 6G. Its hard to say how high I got it up due to blackout, but it seemed like I in sharp turns could reach 8G for sure, and it might have reached 9G, with no damage.

------------------
Ltn. Snefens
RO, Lentolaivue 34
My own homepage

[Citabria]

bolillo I've used the AH P-38 as my main ride since it was added to AH and its latest flight model in 1.04 is the worst it has ever been.

I have a question for you bolillo:
when the p38 compressed did the ailerons also cease to function? in Aces High they do.


it now stalls and instantly snap rolls at any speed. (I lobbied hard to correct this and it was toned down although not fixed in 1.03) the P-38 stall model is seriously flawed in 1.04 again with new flight model tweaks

its compressibility is total past around 475 (lower at hi alt) HTC used the anti stick stiring code to simulate compressibility it seams.
there is no buffeting at any speed or prgressive nose tuck, its all or nothing stall/mach.6 or otherwise.

as for speed and climb the actual AH P-38 is slower by a few mph and does not climb as well as in the Aces High web page charts

and yes this is the slowest speeds available for the P-38 and its even slower than them.


but aside from how screwed up the flight model on the P-38 is I love the challenge of flying it so I still recomend it for experts looking for a challenge.

but those are just stats...
playing the game with the plane is always a bit different than what the stats say:

what the P-38L does well in AH:
great vertical fighter above 20k
great buff killer with nose guns
good jabo
good dive
good climb
good speed above 20k vs most other fighters
good roll performance at high speed


what the p38L does poorly in AH:
weak turn ability (turns only slightly better than p47)
disgusting stall characteristics
slow top speed at low altitude
poor roll response at low speed
guns have weak snapshot hitting power (needs tracking shot to damage)
compressibility a big problem at high altitude in AH even w dive flaps because aileron roll control almost nonexistant when compressed although the elevator is usable with dive flaps extended.


I know I sound critical of the P-38L but I still love flying it.

so if someone as critical about the plane as me still loves to fly it in the game it must be doing somthing right.    

give the Aces High P-38L a try... its got problems but its still not half bad    

[This message has been edited by Citabria (edited 12-09-2000).]

[LLv34_Snefens]

Ok, it doesn't seem as good as I made it sound like. I take Citabria's word for it. He got about 1000 times more flying hours in AH's P38 than me  

[bolillo_loco]

sneff, were you the guy who was mean to my plane at eaw? one or two of those LLv_34 guys must have always thought I was cold because they constantly set my plane on fire to warm me up. I guess I will just have to down load it and try it out.

citabria I know everybody tends to model this plane at its lowest performance figures, but with out flaps it should turn only slightly better than a jug. with any type of flap setting it is another story though.

I dont know about its ailerons at high speeds, but I think what alot of people seem to miss is all these planes at speeds of mach .7 became dangerouse to fly.

[bolillo_loco]

can somebody explain to me why this plane has single engine habbits on take off? why is it affected by prop torque when it had none. why does it spin when it is stalled?

[LLv34_Snefens]

Yep that could have been me. I believe we met a couple of times in EAW.

On take off remember that there is wind present. I don't know how much of a factor this plays tho. One could try to remove wind in the offline arena settings to test.

I got a question tho. I don't know the answer, but if its a NO, this might be reason for the behaviuor.
Now I know very little of aerodynamics, but HiTech posted the 5 forces they modelled from the prop in the thread about the N1K2. Are all these forces negating each other when using two counterturning props?

<edit>I just saw a thread on this prop issue was started, so go look there instead.

[This message has been edited by LLv34_Snefens (edited 12-09-2000).]

[bolillo_loco]

I probably know less than you sneff, but two props working against each other at equal power would cancel each other out. I do not know all the big five dollar words, but for some reason when a single engine plane increases its speed or power settings, it becomes unstable or wants to not fly along the same flight path as it was before the power or speed change took place. so you would have to trim the plane for every speed or power change.

with counter rotating props this wasnt a problem. so for the 38 it wouldnt matter what power setting you use or how much you change speed so long as you stay with in the flight envelope of its speed limitations you wouldnt need to trim it to fly straight. or so I have read.

as far as wind affecting the planes I flew off line. I feel it wasnt possible because I had not even begun to roll much. as soon as I jammed on the throttle the plane pulled, to the left I think it was. also inflight it spun out just like single engine planes when it stalled. thats odd. could somebody explain this. is the flight model just wrong and hasnt been fixed yet?

[Rickenbacker]

The yawing on takeoff is due to wind effects. If you ever take off straight into the wind, or with it, you won't notice it at all.

All planes will spin if you make them  . AH planes tend to drop a wing in a stall, even when you're flying relatively cleanly, but this might be realistic, I've never flown any of them in real life. You have to provoke them pretty hard to actually spin though.


 

[bolillo_loco]

P-38s did not spin when they stalled if both engines were running. no sooner I hear the stall warning the plane snaps into a spin, this is not as it is described by many pilots and the pilots manual. I have seen this error at eaw. the plane stalled and spun much more quickly than did the other planes. what gives?

also I tried to roll this plane at 200 mph ias and it took 30 seconds to complete the roll. is it me?

[LLv34_Snefens]

Ok, just tried putting wind to zero and like it was said you'll have NO need of rudder on take off.
For setting the wind to this, type:

.wind 0 0 0

in the text box.

As for the roll I can do a roll at 200 IAS in about 6 secs with no rudder input.

I still no nothing about stall/spin characteristics.

[Citabria]

I've flown that damn p38 more than anyone else who ever played this game and I fully agree with you about the awful stall modelling.

its worse in 1.04 than it was in the 1.03 release which wasnt bad.