P-38 Bugged

Discussion in 'Engineering Retrospective' started by -ALW-, Jan 25, 2003.

  1. Bobby

    Bobby Well-Known Member

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    Спасибо за пояснения. Я согласен, что нет точных данных, но можно востользоватся методом сравнений.
    Из отчета следует, что
    По отчету испытаний 190А3 у земли быстрее девятки на 10-13км/ч у нас 22км/ч, можно предположить, что испытанная англечанами модификация уступала 190А4 реализованному в ВБ. Вероятнее что там был старый двигатель, тем более что там отмечается, что бвигатель сел, и они не смогли провести полные тесты с Тайфуном.
    Второе, Характеристики акселирации (9 вс 190) в твоей выдержке не приведено, но сказано, что "горизонтали cкорости и скороподъёмности оба самолёта
    были примерно равны" видимо в акселирации они то же не сильно отличались. Из графиков ВБ это так же видно. Но в том же отчете сказано, что Тайфун имел преимущество в акселирации по сравнению со 190, а следовательно и с Спит9. Чего нет в ВБ.
    Я согласен, что испытывался опытый вариант Тайфуна, и по нему нельзя сделать окончательных выводов. Как изменились его параметры при постановки в серию?
     
  2. -exec-

    -exec- FH Consultant

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    Last edited: Feb 13, 2003
  3. bizerk

    bizerk Well-Known Member

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  4. -ALW-

    -ALW- Well-Known Member

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    FH Launcher v1.51 released

    :director: .....FH Launcher v1.51 released...... :director:

    ................P-38 speed limit of flaps extending increased, effectiveness of full flaps improved, stall speed slightly decreased .................


    :@prayer: :@prayer: :@prayer:
    :cheers: :cheers:

    Thank you for update and changes!!! I don't know if my input made an impact, but I hope it did this time!
    Great work guys!! I'll have to give that Tempest a try when it comes out as well.
     
  5. -ALW-

    -ALW- Well-Known Member

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    Ah, yes, this is me ;-)
     

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  6. -ALW-

    -ALW- Well-Known Member

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    .....FH Launcher v1.51 released......

    "Hi Rgreat,
    I tested the P-38 tonight and have a question.
    Why does the P-38 suffer from the effects of torque roll? The P-38 cancels out its own torque through counter-rotating powerplants which are equidistant from the plane's centerline. According to physics, it CANNOT torque roll when both engines are set to the same power settings. (Which is always the case in FH .)
     
  7. rgreat

    rgreat FH Developer

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    Re: .....FH Launcher v1.51 released......

    P38 is not affected by torque effects in WB. THis is modelled. (in same settings for both engines of couse).
    I did not know how you manage to get torque roll.
     
  8. -ALW-

    -ALW- Well-Known Member

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    Re: Re: .....FH Launcher v1.51 released......

    If the P38 is not affected by torque what is it I'm experiencing when I make Left or Right banks, and pulling up for a loop causes the plane to whirl clockwise?
    I could either post a film or have you follow me online to watch and see.
     
  9. rgreat

    rgreat FH Developer

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    AFAIK that effect is based not on torgue, but on aerodynamic.
    More detailed: due to differences in airflow one wing can eventially get bigger ange of attack then other, and as a result lost lift before other wing do the same. So plane will roll on that wing, and can even go to the spin.
     
  10. -ALW-

    -ALW- Well-Known Member

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    (What is AFAIK?)

    This is only to the right though, and it is documented in stories from those that tested the planes that they did not "drop tips" causing a "Snap-Roll". Proper airfoil design of the aircraft wings, and the fact that there is more airflow over these surfaces is a result of two engines/props delivering equal amounts of airflow for lift, also cancelling any anomolies. (Note: Flush rivoted surfaces created a very stable, low drag airflow)

    One should consider the aerodynamics required to lift the plane off the ground and the speed indicated, plus air-flow created by the two engines/props. It is obvious that the counter rotating props will create EQUAL lift for each side and cancel any one-sided anomolies. If speed drops to the point where aerodynamics loses it's positive affect on the aircraft, then the dependancy for stability is upon the prop pull and lift.

    Some of my testing on WarBirdsFH suggests that the plane has very good lift for takeoff but then seems to lose that feature once airborne.

    Test: P-38F, Fuel:100%, Payload: Bombs; 2,000lb.
    Liftoff is at 110mph fully loaded, no flaps, no WEP.

    Test: P-38F, Fuel: 50% Payload: Bombs; 0lbs.
    Liftoff is at 100mph, half the fuel load, no flaps, no WEP no extra payload.

    (Note: Default setting under WB)


    Test: P-38J, Fuel:100%, Payload: Bombs; 2,000lb.
    Liftoff is at 130mph (odd) fully loaded, no flaps, no WEP.

    Test: P-38J, Fuel: 50% Payload: Bombs; 0lbs.
    Liftoff is at 120mph, half the fuel load, no flaps, no WEP no extra payload.

    (Note: Default setting under WB)


    Test: P-38L, Fuel:100%, Payload: Bombs; 2,000lb.
    Liftoff is at 120mph (odd) fully loaded, no flaps, no WEP.

    Test: P-38L, Fuel: 50% Payload: Bombs; 0lbs.
    Liftoff is at 110mph, half the fuel load, no flaps, no WEP no extra payload.

    (Note: Default setting under WB)


    One thing I must add here. It is odd with my tests to see what each plane is capable of, as far as takeoff speeds. They seemed worsen with each next "better" variant aircraft. The only performance difference between those variants was the HP of the engines and a dive flap, giving them a higher top speed and better diving platform and that's it.

    (Note: Flaps were not normally used for takeoff but rather during combat.)
    Another note: After lift-off, if you use excessive pull-back while the plane becomes airborn it WILL "Snap-Roll" to the right (clockwise).

    I will re-paste what was posted before to help reiterate that information.
     
  11. rgreat

    rgreat FH Developer

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    You forget about increasing weight (and wingload) of each new wariant of P38.
     
  12. -ALW-

    -ALW- Well-Known Member

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    I know, but that's a moot point anyhow. :dunno:

    What can you say about the other information I presented?
     
  13. Jochen

    Jochen Well-Known Member

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    Hi Rgreat,

    Regarding the P-38L:

    Wing Loading: 53 pounds per square foot.

    Power to weight ratio: 5.47 pounds per horsepower.

    Why this information cannot be treated the same as information for the Fw-190A, despite the similar numbers: We are still neglecting the fact that the P-38's unique power arrangement cancels out all torque effects, but this is not modeled in any version of WB. If you pull back on the stick hard enough in any single engined aircraft, you will stall, and your engine torque will take over, directing your plane into a spin. With the P-38, this is not the case; as long as power output is the same from both engines, it is incapable of a torque roll.

    This is the reason why the P-38 was able to make such a tight turn at 140mph (tighter than that of some Bf-109 models,) and this is exactly why no single engined fighter could hope to follow the P-38 into a flat turn on the deck; there are combat accounts of Bf-109s spinning into the ground while attempting to follow a fighter which does not suffer from torque.

    As ALW's pilot account states, there is no risk of a snap roll.

    Unfortunately, the P-38 in WB does, quite unrealistically, suffer from torque at certain G forces and speeds. Combined with overblown stall speeds and spin characteristics, we have a Lightning which is nothing like the real one in terms of maneuverability.

    Regards,
    Jochen
    ---------
    Hi ALW,

    AFAIK means "As far as I know," AFAIK. ;-)

    Regards,
    Jochen
     
  14. badger

    badger FH Beta Tester

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    I still don't understand what you trying to say.
    You mean P+38 cannot be stalled and spinned as it doesnät have torque? It is plain and simple wrong:

    "SPIN INSTRUCTIONS, PLEASE"
    Submitted by : Edwin C. Baquet, Lt Col, USAF (RET)

    It was my first combat mission after being assigned to a Fighter Group in Italy. I was a P-38 pilot -- fresh from the states -- with 37 hours and 15 minutes experience in the "forked tail devil".

    Today's Target: Blechhammer, Germany

    I was assigned to fly a flight leader's wing. We took off on schedule with me glued to his wing. Our squadron of 16 aircraft soon formed up. We set course to catch the bombers and give them cover through the target area. I soon realized that I had missed part of the briefing somewhere. Adding to my concern; my radio was tuned to the bomber frequency in case they wanted to contact us. No one told me that radio jamming was part of this war game. All I could hear in my headset was Gor-ring, Gor-ing. I knew Herman Goering was sending his entire Lufwaffe after me.

    We joined our "Big Friends" in the target area. With no cockpit heat my cold hands and feet were killing me, but I hung in there. Obviously I was not dressed properly for this type of operations. We were crisscrossing over the bombers at 32,000 feet -- an altitude that I had never experienced before. My training in the states had been mostly at low level with little use for oxygen or a mask.

    All of a sudden my leader made a hard break to the right and I did my best to stay with him. The turn was too tight and my bird snapped over into a spin. I had never spun a '38 before. I wondered if it was the same recover procedures I was taught in the BT-13 -- but I had to try something. I turned the wheel against the spin and noticed considerable noise coming from the nose of my aircraft. During my panic I was squeezing the gun trigger and spraying all of Germany with my .50 calibers!

    The spin stopped but the dive did not. The high altitude, thin air, high speed and minimum air flow over the elevators resulting in my stalling the aircraft each time a recovery was attempted. Many ideas entered my mind. How do I slow this bird down? Throttles idle? Flaps down? Gear down? I decided none of the above. After two more attempts I decided it was time to bail out. The tops of an overcast were approaching fast which I estimated to be somewhere between 15 to 20 thousand feet. I certainly wasn't going into that stuff going straight down.

    I reached for the canopy locks but decided to give a recovery one more try. The bird responded and I was flying again. But where was everybody? My head was spinning like a top, looking for enemy fighters or friendly anything. My oxygen gauge read zero. I knew the "Jerries" would get me or I would pass out from the lack of oxygen. To my relief I spotted another P-38 off to my left. God, I'm saved! I flew over and latched onto him, and he just happened to be my element leader. He had also spun out.

    We soon descended over the Adriatic Sea and landed at our home base. My crew chief greeted me with all smiles as he looked at the smoke around the gun ports. "Hey, Lieutenant, looks like you saw action on your first mission." I sheepishly looked back at him and said, "Yeah Sarge, I sure did" and then jumped in the jeep to go debrief.



    http://www.p38assn.org/stories_03-01.htm


    Next:

    The 51 also has a great wide gear, but you had to stay on top of the landings with it also. In all the planes that I have flown, the 51 is the only plane that I ever almost lost on landing. It is like a big AT-6 Trainer but with a wide gear and a hell of a lot more power. Making a three point landing is fine in most cases, however if one wing tank is heavier on fuel than the other it can make for a hairy time. Coming in for a normal three point landing, I flared out and stalled a little too high. The wing with the most fuel just fell out from under me and my right wing scrapped the ground. I did manage to straighten it out after taking about an inch off the end of the prop and scraping a good piece from the wing tip, but the embarrassment was never lived down. From that time on I always just took it easy and wheeled them in. Torque on takeoff in a 51 was really a bitch if you failed to have the trim tabs set to compensate for that big fan in front. Trying to hold it on takeoff without the trim was almost impossible. I did it once and it taught me never to forget to set it again.

    Reading SPIN CHARACTERISTICS on page 8 of the operating instructions for the P-38 reminds me of one unintentional spin recovery that I will never forget:

    I had intentionally spun the plane before and the normal spin recovery is simple and easy to accomplish, opposite rudder, pop the stick (wheel in a 38) and dive out of it. However, this day, as I was upside down on my back with my gun cameras blasting away at my wingman during a rat race, I stalled into a really great flat spin. After about three turns I managed to come out of the spin and pulled back on the yolk. The ground looked to be coming up in a hurry, so being in too much of a hurry I pulled back too hard on the yolk and went into a secondary high speed stall and went into a spin in the opposite direction. This is not good and when hearing my buddy calling the field telling them that a 38 was going in and to send out the crash trucks I felt that this really wasn't my day. Opposite rudder, pop the stick to come out after another two turns and then pulling back slowly. This time I did manage to come out of the spin. I pulled out over a little meadow not more than five feet from the ground. I can still see the trees on both sides of my plane as I pulled out and up. The lesson here is that you never give up. Never stop flying the airplane. Wait until you have landed before you panic. From that experience I have to admit that I was shaking a bit after I had landed. I have seen friends die because they gave up and didn't fly the plane all the way to the ground.


    http://home.worldonline.dk/winthrop/stanwood.html

    Spin happens not because of torque, but because one wing stalls earlier then the other. Is it too complex concept to understand?
    Do you know why and how Thomas McGuire died in this "wonderful&spinless" P-38?

    The idea that P-38 was easy to fly at low speeds due to absence of torque doesn't mean it turned well at those speeds.


    Let's read a bit about turning ability of P-38:

    Was it as maneuverable as it looks - also compared to the P-47 and P-51?

    I would probably have to say no. With the combat flaps it did turn pretty tight, but the 38 was better as a hell-bent-for-leather-downhill-attack and then keep-on-going plane. Also I have a preference for a stick rather than a wheel and am sure I could left hand break with a 51 tighter than a 38. There is no doubt that the 51 was by far the better combat plane of the day. The Jug was for it's size surprisingly very maneuverable and built to withstand a lot of punishment. I remember flying a 47 through a thunderstorm in the South Pacific. I slowed it down, put it on Auto Pilot and although I almost lost my eye teeth, it came through with no problem except for a canopy-bumped head. This was back in the days before hard hats and leather helmets don't take up a lot of shock.


    http://home.worldonline.dk/winthrop/stanwood.html
     
  15. -ALW-

    -ALW- Well-Known Member

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    Originally posted by badger

    Listen dimwit, we aren't addressing you, we are discussing this with rgreat. I will leave it to him to decide what is reasonable.
    First off, we do not say the P38 cannot stall. Any and all aircraft stall, spin, and crash if flown like an idiot.
    He had what, 37 hours of experience? You think I'm going to accept a greenboy/wet behind the ears 19 year old boy describe charactoristics of an aircraft that had not even experienced combat? What was his throttle setting? Throttle was set to a much lower setting to stay with bomber groups. He was at a high altitude. He didn't even have use of oxygen masks, plus his limbs were rather cold, and I'm sure stiff. Thinner air...not exactly perfect combat conditions.
    I do think this sums it up...It was my first combat mission after being assigned to a Fighter Group in Italy. I was a P-38 pilot -- fresh from the states -- with 37 hours and 15 minutes experience in the "forked tail devil"......My training in the states had been mostly at low level with little use for oxygen or a mask....I had never spun a '38 before....Many ideas entered my mind. How do I slow this bird down? Throttles idle? Flaps down? Gear down? ....My oxygen gauge read zero. I knew the "Jerries" would get me or I would pass out from the lack of oxygen... Yeah, sounds like a chap for good advice aye?

    What does a P-51 have to do with all this? Inverted, flying with a gun cam, rat race, showing off etc etc...yeah, you're asking for it you young punk lol. I think if one understands airfoils and the aerodynamic properties it can be understood the problem is here.

    No, it's not too complex, and don't you go naming a great pilot, while in spite giving a sardonic comment about this aircraft SIR.
    On McGuire, here is the impending moments....McGuire's response was immediate as he turned sharply to the left, but something went wrong as his Lightning shuddered and threatened to stall. He sharply increased his turn in an attempt to get a shot at the enemy fighter, but his plane lost momentum and snap-rolled to the left. It was last seen in an inverted position with the nose down about 30-degrees....
    Ok, what went wrong? We don't know do we? Hydraulic problem? Controls problem? Pilot error?

    That IS NOT the basis of this argument. The intention is not to have a zeke-38.

    Ok, let's stick with the subject. We are talking about the P-38 as it is the one being discussed. This comment from a P47/P51 pilot bears absolutely no basis for viable facts. He aparently had most of his time in his beloved P51 and P47. How many hours of flying time elapsed before his coming to that conclusion aye?
     
    Last edited: Mar 2, 2003
  16. rgreat

    rgreat FH Developer

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    Heh, -alw- , Badger comments looks more convincing to me. ;)

    Attacking other person instead of arguing is not a good way to win in discussion imho.
     
  17. Kutya

    Kutya Banned

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    Maybe a bit off topic (I don't really think).

    Just a question. Why do you men need to discuss it in such a disgusting way? This kind of agression is pathetic. :rolleyes:
     
  18. -ALW-

    -ALW- Well-Known Member

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    And you find this information convincing to the fact that it is accurate that the P-38 was an uncontrollable aircraft for anyone to fly????
     
  19. -ALW-

    -ALW- Well-Known Member

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    Prove to me what is convincing other than he is on your side?? :dunno: :deal:

    Attacking a person? I'm attacking his information. :dura:
     
  20. -ALW-

    -ALW- Well-Known Member

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    "You don't really think"? That is the problem I find here a lot with many people.

    There is nothing disgusting about it, the information is fallible and so are the pilots, so I treat it that way.

    Facts Facts Facts

    I used to think the P-38 was undermodeled before it was made :lamer: .
    The things that were undermodeled then were:
    Fuel: Leak from fuel tanks...from a self sealing tank?
    Fuel Fires: Self sealing tanks?
    Fuel Leak: From one side of aircraft and both tanks all leak out?
    Top Speeds: Unrealistic by fact; but that's another discussion.
    Flaps: Un-usable untill at much lower speeds.

    My whole impression is that some unnamed people didn't like that the P-38, under their lack of knowledge was performing quite well, yet, with it's lack of performance.

    One more thing...I do wish rgreat would respond to each of someone's content of the post, rather than pick something to respond out of context.
     
    Last edited: Mar 2, 2003