Author Topic: P38 has been Porked  (Read 2886 times)

Offline Raptor

  • Platinum Member
  • ******
  • Posts: 7577
P38 has been Porked
« Reply #30 on: April 02, 2006, 11:02:38 AM »
Like I said in my original post, yes it seems more realistic with planes with conventional flaps. Now they can only really use one or two notches of flaps. But the P38 is meant to fly with 3 or 4 notches of flaps out. Full flaps is 5 notches. The old FM was unrealistic, I was able to out turn spits with 2 DTs on. Now it is unrealistic because even with no DTs, heavy 109s don't have trouble out turning a P38. My arguement is the new stall feature does not seem to add any lift, only drag.

Offline Murdr

  • Platinum Member
  • ******
  • Posts: 5608
      • http://479th.jasminemaire.com
P38 has been Porked
« Reply #31 on: April 02, 2006, 11:50:45 AM »
Here are the stall speeds listed in the Pilots Manual.


Here are the speeds in ISA that the buffet kicks in at 1000 Ft, idle power with auto-pilot engaged in a P-38J with aprox. 2010 lbs of fuel and ammo, for an aproximate gross weight of 15,000 lbs.

No Flaps 107 mph
1 notch  106 mph
2 notch 105 mph
3 notch 106 mph
4 notch 99 mph
Full Flaps 103 mph
Full Flaps & Gear 89 mph

Quote
Lockheed's Hanger Flying Issue: 6, test pilot Ray Meskimen

For greatest maneuverability we have found that the maneuvering flaps should be extended only long enough to complete the particular maneuver and then be retracted immediately. For example, in an effort to stay on an enemy's tail, you might feel in a tight turn the buffeting which is characteristic of an accelerated stall. You can "reef" her in and tighten your turn by lowering the maneuvering flaps until you have completed the maneuver, then retract them. By doing so immediately, little air speed is lost, and the plane is set again for maximum operations.

With virtiually no difference in conditions for stall between clean confituration, and maneuver flap setting, there is no "reefing" in.

For delerium, here is Tony Levier's description of the stall from Hanger Flying Issue: 2
Quote
The '38 is a pilot's dream-come-true when it comes to the stall characteristics. They are unusually good and-although not generally used-are worthwhile investigating so that in an emergency you will know what performance to expect from your ship. We have discovered that the power stall occurs at about 70 M.P.H. with about a 50-foot loss of altitude. The counter rotating propellers eliminate torque and there is no tendency for either wing to dip or fall away.
 
You will find "she" is just as steady in a power off stall with gear and flaps retracted or extended.One of the finest characteristics of the '38 is the accelerated stall. Such stalls, accompanied by normal buffeting, occur on any ship when the angle of attack is increased to the point that the airflow over the wing becomes turbulent.
 
As you know, this can happen in sharp turns, pull-outs or other severe maneuvers. The '38 is designed to take the buffeting of the stall and has no tendency to fall off on either wing at any altitude. If combat necessitates, you can hold it in the accelerated stall as long as you can take the buffeting -- the ship will take it much longer. To get out of an accelerated stall immediately, ease up on the stick, permitting the airflow to reestablish normal lift.


For Kweassa regarding low speed maneuvering:
Quote
The Great Book of WW2 Airplanes, P-38 Chapter by Jeffrey Ethell quoting Major John A. Tilley of the 475th FG

John A Tilley, a squadron mate of McGuire's and an ace himself, remembers that Mac was notorious for going "round and round" with Japanese fighters.  McGuire told those under his command never to turn with an enemy fighter in the heavy'38 but he did it anyway with great sucess, particularly at low altitudes and low airspeeds of 90 mph.
...
Althought dogfighting in the Lightning was often played down officially, it was more common than not.  Tilley remembered "most of our fights with the Japanese started out above 20,000 feet but damned soon everyone was milling around on the deck.  And that lovely Lightning just didn't have any competition at low altitude.  I've flown the P-51 (liked it very much) and the P-47 (disliked it very much), and I've engaged in mock dogfights against just about all our WWII fighter planes.  The only one the ole Lockheed Rocking Chanir and I had trouble staying behind was a pretty savvy Navy type in an F4F Wildcat.
...
"Alright, so how come I got my second kill by turning a full 360° circle to the left, at low speeds and on the deck with and Oscar?  Primarily I think it happened because the Jap and I both believed he could out turn me.  I never would have tried to stay with him if there hadn't been 12 of us and only two of them.  I figured I could always holler for help if I got in a jam.  And I'm sure the Jap figured the usual tight turn was his best bet when he didn't have enough air under him for a split-S.  Miracle of miracles, the big old P-38 actually turned inside the nimble little Oscar.  I was on the deck, in a vertical bank, the airspeed under 90 mph, and the yoke was bucking and shuddering in my hands.  That turn was nothing more nor less than a controlled stall.  But without torque (good old counter-rotating engines) I didn't worry about 'snapping' out of control and into a spin, as with a single engine aircraft, so I was able to pull enough lead for my guns to really hit him hard.  By the time we had completed 360° of this turn he was a ball of flames, and my aircraft was drenched with oil from his engine.  I couldn't see a thing through the windshield so I had to ask a squadron mate to lead me home."
« Last Edit: April 02, 2006, 12:41:42 PM by Murdr »

Offline Morpheus

  • Plutonium Member
  • *******
  • Posts: 10224
P38 has been Porked
« Reply #32 on: April 02, 2006, 11:59:53 AM »


This sounds nothing like the 38 in AH2.

Uncontroled most often unrecoverable flat spins from as high or higher than 15k down to the deck and into the dirt.

I have been flying the 38 for as long as I've been flying AH. In AH 1 there was almost no tendency for the plane to get into a flat spin. (Do a search) When AH2 came out, my first post about AH2's "new/better FM" tweaks was that the 38 now was able to enter a stall/flatspin that was hardly ever recoverable. I remember going afk ending up at 20k with a con on my long 6. I went to reverse slowly to meet nose to nose and before I could reverse fully I was in a stall and falling straight down... from 20k or so right into the water. It was an agressive reverse, but no more agressive than the 1000's of other times I've reversed with someone on my 6. My speed entering the reversal was aprox 250mph after I had been level for a short while.
If you don't receive Jesus Christ, you don't receive the gift of righteousness.

Be A WARRIOR NOT A WORRIER!

Offline Murdr

  • Platinum Member
  • ******
  • Posts: 5608
      • http://479th.jasminemaire.com
P38 has been Porked
« Reply #33 on: April 02, 2006, 12:03:32 PM »
It is, and should be possible though to stall one wing while maneuvering hard, and send the 38 into a spin.  I do have a quote here from the same book describing that situation happening in combat.  In AH2 this is most likely to occur in a nose low turn.

edit: cant seem to find the quote now, may have been in another book.  Anyways, that pilot had no stateside training in the 38, and was bounced on his first combat mission.  When he tried to split-s he threw himself into a spin, and bailed out.
« Last Edit: April 02, 2006, 12:36:41 PM by Murdr »

Offline wetrat

  • Gold Member
  • *****
  • Posts: 2117
P38 has been Porked
« Reply #34 on: April 02, 2006, 01:14:49 PM »
Quote
Originally posted by MOSQ
Ki-84 seems to be the same.
yep
Army of Muppets

Offline Grits

  • Platinum Member
  • ******
  • Posts: 5332
P38 has been Porked
« Reply #35 on: April 02, 2006, 01:42:28 PM »
Morph, keep in mind that those speeds and that behavior is describing a straight and level 1G attitude, whereas your example was not straight and level, even a very low G turn can make a plane (any plane) enter a spin/stall.

Offline Lazerr

  • Platinum Member
  • ******
  • Posts: 5005
P38 has been Porked
« Reply #36 on: April 02, 2006, 02:11:58 PM »
Yeah, 38G seems to do ok against the turn and burn, but the others are porked.


Glad Murdr got on here and posted some cold hard facts.  This bird is fubar, it shouldn't just fall out of the sky with full flaps at 150-200mph.
Please FIX!!!:cry

Offline Raptor

  • Platinum Member
  • ******
  • Posts: 7577
P38 has been Porked
« Reply #37 on: April 02, 2006, 02:24:51 PM »
I just did a test offline to compare with what Murdr posted.
All of my tests were done with 25% fuel, began at 4k, and loaded 200 rounds per gun, 150 rounds in 20mm.

P38L - Power Off Stall Test
Flaps and gear up

- stall horn began to sound at 120mph Indicated Airspeed, 128mph True Airspeed.
- Began to buffet at 110mph indicated airspeed, 116mph True Airspeed
- Began to stall at 105mph indicated airspeed, 109mph True Airspeed
Flaps and Gear Fully lowered
- Stall horn sounded at 96mph Indicated Airspeed, 102mph True Airspeed
- Began to buffet at 90mph Indicated Airspeed, 96mph True Airspeed
- Began to stall at 80mph Indicated Airspeed, 86mph True Airspeed

P38J - Power Off Stall Test
Flaps And Gear Up

- stall horn began to sound at 121mph Indicated Airspeed, 125mph True Airspeed.
- Began to buffet at 105mph indicated airspeed, 109mph True Airspeed
- Began to stall at 100mph indicated airspeed, 104mph True Airspeed
Flaps and Gear Fully lowered
- Stall horn sounded at 93mph Indicated Airspeed, 101mph True Airspeed
- Began to buffet at 86mph Indicated Airspeed, 94mph True Airspeed
- Began to stall at 80mph Indicated Airspeed, 86mph True Airspeed

P38G - Power Off Stall Test
Flaps And Gear Up

- stall horn began to sound at 115mph Indicated Airspeed, 123mph True Airspeed.
- Began to buffet at 97mph indicated airspeed, 104mph True Airspeed
- Began to stall at 96mph indicated airspeed, 102mph True Airspeed
Flaps and Gear Fully lowered
- Stall horn sounded at 94mph Indicated Airspeed, 101mph True Airspeed
- Began to buffet at 82mph Indicated Airspeed, 89mph True Airspeed
- Began to stall at 75mph Indicated Airspeed, 86mph True Airspeed


Other notes:
- With Gear and Full Flaps Extended, flying at Full throttle, the P38L would level off speed at 83mph Indicated Airspeed, 88mph True Airspeed
- With Gear and Full Flaps Extended, flying at Full throttle, the P38J would level off speed at 83mph Indicated Airspeed, 88mph True Airspeed
- With Gear and Full Flaps Extended, flying at Full throttle, the P38G would level off speed at 79mph Indicated Airspeed, 83mph True Airspeed
- All P38s rapidly lose airspeed as soon as flaps are deployed. Will go from 120mph to 80mph in less than 4 seconds. Even with full throttle.

I would say Possible Human Error of 3
« Last Edit: April 02, 2006, 02:27:34 PM by Raptor »

Offline Kweassa

  • Platinum Member
  • ******
  • Posts: 6425
P38 has been Porked
« Reply #38 on: April 02, 2006, 02:50:49 PM »
Murdr,

 One needs a complete data on the types and configurations of the plane tested, in order to compare it to the game. The type of plane teste, and some other parameters. For a loose comparison, here are the figures I got for a quick test for two P-38s, in turn.

-Parameters-
* 75% fuel, clean configuration
* 1k alt (minimal difference between TAS and IAS)
* Power Off stalls during level flight
* props feathered
* maintain manual control so the climbrate indicator holds 0
   variance in climb/sink contained under +/- 50 ft at a given time
* when a plane can no longer hold the "0" point, and gives away
   with sudden fall of the pitch, that point is considered 'stall'

-Planes-

P-38G
- no flaps: 95mph
- full flaps+gear: 72mph

P-38J
- no flaps: 110mph
- full flaps+gear: 78mph

 The impending signs of stall, and the "mush", is all as described in the report. The stall warning starts to get louder, the plane shakes, and the climbrate indicator cannot hold "0" any longer. The pitch starts to drop suddenly, and as if some magic is occuring, the planes just stops buffeting and mushes over despite elevator input via stick. No tendency to spin.

 When left alone at clean configuration the plane gains speed, the stick input comes alive, and the plane recovers. Unfortunately, with the gears out and flaps at landing position, Power Off stalls were unrecoverable naturally - probably due to the fact that the plane had no thrust at all and mega drag hanging under it.

 ....


 The real problem where people seem to be always disagreeing about, is what might happen at accelerated stalls..

 Take into consideration that every one of those accounts have some very specific conditions on the point that the P-38 will refuse to stall out violently. Meskimen's account for example, specifically relies on a situation where the flaps are momentarily deployed and then quickly tucked back in - indicating an 'instantaenous turn' rather than a steady and continuous turn. This, is possible with AH2 P-38s.

 The descriptions of the plane's inherent resistance to spins, is associated with stalls during level (essentially) level flight, test prcedure conditions with either Power On or Off. Tony Levier himself, in the very account you've quoted, clarifies;

Quote
One of the finest characteristics of the '38 is the accelerated stall. Such stalls, accompanied by normal buffeting, occur on any ship when the angle of attack is increased to the point that the airflow over the wing becomes turbulent.


 By clarifying that it happens to 'any ship' - he also implies it DOES happen to the P-38 indeed. Also note that he clear mentions accelerated stalls separately, apart from stalls during level flight.  


 Also - look at the last account of McGuire's that you were kind enough to post for me;

Quote
I was on the deck, in a vertical bank, the airspeed under 90 mph, and the yoke was bucking and shuddering in my hands. That turn was nothing more nor less than a controlled stall.


 This, is the part which is described as 'buffeting effect' in AH2, and indeed, even in the game, you can maintain that status for quite a long time without snapping over. If it were an AH2 Fw190 for example, the plane will just instantly flick over to its left side when the buffet starts to show. The real question here is, what happenes if you go even over that?

 Will the P-38 still refuse to spin out of control?

 In real life controlling the planes were a much heavier burden than the troubles we go through with a small joystick. Pulling the stick aroundto start turning the plane upto Gs itself required some amount of strength and control. When the plane begins to stall, the 'buffeting' manifests in your hand, as the stick starts to vibrate and shake, indicating a stalled status.

 My take is that this is usually more than enough motivation to let the pilot ease off on the stick and return to controlled flight. In AH2, every single game pilot walks over that line routinely. Yes, the AH2 P-38 will dip one wing and fall under a spin during a turn. But my take is that this is a result of going over the 'controlled' status of the plane and pushing the stall even further upto a point of no return - which, quite contrarily, was something even the best of pilots would rarely venture into, and often payed price with death when they did so.

 In other words, when you take up a P-38, and go into a sharp left turn, the plane shakes around. This is the point where McGuire, in the above account, already considered as a stalled status which he claims could control(and also the point where many single engine fighters would become highly sensitive and susceptible to falling under a 'snap roll' - which, is also true in AH2). This tendency is also observed in AH2 - keep a gentle coordination of the controls, and the P-38 will continue to turn despite the buffeting.

 However, the point where the game pilots complain about that the P-38 will spin, IMO, is actually a point beyond the controllable stall which McGuire above boasts that he had no problem with. He says he pulled enough lead to get a shot in, but that does not necessarily mean that he just kept on pulling the stick harder and harder all through the buffeting.

 So, what would have happened, if McGuire pulled the stick even harder despite the "yoke bucking and shuddering in his hands"? I say the P-38 would have spinned to one side and crashed, like any other plane. Which ironically and ultimately, killed McGuire on his last mission.

 To sum it up even shorter, I think the reason the AH2 P-38 'snaps' to one side, despite its famous reputation for being resistant to violent stalls, is just because game pilots would frequently step over the line which should never have been crossed, torque or no torque. Like bozon said some time ago, if normal flow is cut off from the plane then anything can happen.

 Remember, in real life the 'buffeting' itself, would have been something scary enough to motivate the pilot to back off on the controls. In AH2, we just ride the buffeting for fun - something IMO, only a seasoned expert would ever do in real life. And only when we go over that line, and the plane goes out of control, do we consider it as a 'stall' - despite the fact in real life, that would be a point which would have been considered something way beyond a normal, accelerated stall.




 That being said, I'd not object if the P-38 pilots wanted a little more resistance to the 'roll' experienced at the point where the plane is already buffeting. When I tested the plane out, if started a turn and gently tightened it, the plane would start buffeting at some point (the 'McGuire point' as explained in Murdr's quoted account). If I pull a little bit even further than that, the plane would want to spin, just like any plane.

 Given that the P-38 was especially notorious for its resistance and stability against spinning tendencies, I'd say it won't be too bad if the P-38 could resist a little more stck input and harder buffeting, before it 'snapped'.
« Last Edit: April 02, 2006, 02:56:47 PM by Kweassa »

Offline Glasses

  • Silver Member
  • ****
  • Posts: 1811
P38 has been Porked
« Reply #39 on: April 02, 2006, 03:57:01 PM »
Yeah I mean those VSTOL flaps they're suppossed to by themselves lift the aircraft, don't worry about it am sure they'll find something to "fix" this problem quickly.

Instead of doing like the LW guys have done and learn to fly undermodeled planes for quite a while.

Quit your whining,Ameriwhiner!!! :D

Offline Murdr

  • Platinum Member
  • ******
  • Posts: 5608
      • http://479th.jasminemaire.com
P38 has been Porked
« Reply #40 on: April 02, 2006, 04:20:37 PM »
Kweassa,

I made no complaint about what happens at stall in varying conditions.  All I did was answer others complaints.  What happens seems to be modled very well.  I have no idea why you would direct those comments toward me.

Tilley, not McGuire was the pilot in the example I posted performing the "90 mph" 360 on the deck.  I do not believe this can be recreated under the current model due to both the rapid speed drop off, and the high stall speed.

I did make 2 observations.  One is that the stall speeds appear high to me, which in subsequent posts, seems to be a consistant observation.  The other is that the condition with the accelerated stall and maneuver flaps setting described by Ray Meskimen cant be recreated because the window between accelerated stall conditions under clean and maneuver configurations are more like a hairline crack instead of a window.

Offline Kweassa

  • Platinum Member
  • ******
  • Posts: 6425
P38 has been Porked
« Reply #41 on: April 02, 2006, 04:34:36 PM »
Murdr,

 Nor did I say you complained about it. I was merely using what you've kindly posted as a back-up material in answer to the other people who actually did complain about it. I just addressed it to you since you addressed the last account for me - thanks for it, by the way.  :D

 
 On part of measuring stall speeds - I actually found this procedure incredibly difficult - as I had to test it in some 6~7 attempts for individual planes... and I tested only the G and the J, by the way.

 The problem was that the stall buffet does not show up in the film viewer, and also the auto-level function does not keep the plane really level - as stall speeds are reached, for some reason the auto-level function keeps dropping the pitch down a little bit so a small amount of descent rate is maintained. It's almost as if the auto-level function is trying to trade off a bit of altitude to try and maintain a condition as close to level flight as possible for the longest time possible.

 Therefore, I had to manually fly the plane and keep them at 0 climbrate condition - which ofcourse was no easy task... and I disregarded both the sound and the visual buffet effect and used only the pitch-down momentum that threw off the climb rate, as an indicator of the power-off stall(since buffet doesn't show in flims anyway). Then I goto the film viewer, zoom in a bit at the climbrate indicator, wait until it suddenly sinks, pause the frame, and check the speed indicated on the information screen.

 This way, I got figures pretty close to the ones in the report you've posted.


 One last observation, is among the combat accounts, none of the pilots mention anything about flap usage being close to the full, landing position. Ironically, other pilots like Akak do report that while the plane flies within the limits of its first one or two notches, they don't feel any real difference with the plane.

Offline RedTop

  • Platinum Member
  • ******
  • Posts: 5921
P38 has been Porked
« Reply #42 on: April 02, 2006, 09:41:51 PM »
Quote
Originally posted by Hoarach
The 38 is so dweeby we have to give them clueless dweebfire and lgay7 pilots a chance.  :t


I would have you know Kind Sir...I am NOT a clueless Dweebfire Pileit.

I have the Candlestick , rope , knife ,Col. Mustard , Ms. Scarlet , Professor Plum , the Den , Kitchen AND Library for clues....So:p :p :p
Original Member and Former C.O. 71 sqd. RAF Eagles

Offline Morpheus

  • Plutonium Member
  • *******
  • Posts: 10224
P38 has been Porked
« Reply #43 on: April 02, 2006, 11:15:27 PM »
Quote
Originally posted by Grits
Morph, keep in mind that those speeds and that behavior is describing a straight and level 1G attitude, whereas your example was not straight and level, even a very low G turn can make a plane (any plane) enter a spin/stall.


I am calling it like i see it. From AH1 though AH2 with the "new and improved FM". I dont beleive I'm wrong. Why? Because I flew the 38 for hundreds of hours in AH1 each tour. Then was hit with the "new and improved FM" and got a kick in the bellybutton with this fantastic new flat spin.

Keep on porkin em. If that's what brings in the bread, good for HT.
If you don't receive Jesus Christ, you don't receive the gift of righteousness.

Be A WARRIOR NOT A WORRIER!

Offline Grits

  • Platinum Member
  • ******
  • Posts: 5332
P38 has been Porked
« Reply #44 on: April 03, 2006, 12:44:42 AM »
Something I have noticed is all of the twin engine fighters seem to be much more prone to unrecoverable flat spins than single engine fighters are. I dont know why this would be so in R/L, but it is definately the case in AH. While I dont think the P-38 should be immune to flat spins, it should be harder to get into them than any other single or twin engine fighter because of the counter-rotating props.

Regarding the P-38 after the 2.07 patch, I dont fly it enough in general, and I have only flown it once since 2.07 so my experience with it is rather limited.