Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: Vermillion on March 01, 2000, 10:57:00 AM
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1.) Dive Speed limitations: Last night in my testing the P-38 has the same divespeed limitations as the P-51. It starts creaking and groaning at 500 IAS. According to AHT the divespeed limitations for the J/L were 440mph IAS at 1g (p.605), and my P-38 Pilots manual confirms this.
2.) Compression: I realize its not in yet, but couple that with #1 and this bird will be much different. Even with Dive Flaps/Brakes, its noted that the P-38 shouldn't exceed the dive limitations (440) by more than 20mph, because extreme nose tuck will occur.
3.) Induced Drag: The P38 FM makes the old "pre-gelded" Pony (the one everyone complained about no E loss in vertical manuvers)look horrible in comparison. I was amazed how I could pull into turns and manuevers and lose very little E. In the vertical its simply amazing. Last night I was at 30-31k, auto-leveled at WEP waited till my speed stabilized and turned on auto-climb. I zoomed up over 4,000ft !! Try that in any other fighter. This issue is very hard to quantify, but it seems like it is not in the similar range as the other planes currently in the game, especially given the size/weight and other design characteristics of the P-38.
4.) Roll Inertia: To me this is the area that the FM seemed the weakest. Now I don't doubt, given Pyro's meticulous attention to detail, that the sustained roll numbers are pretty close. But the initial roll rate is just as quick, and it reverses with very little to no feel of inertia. Something that should be pronounced given the engines outside the centerline of roll. Here is how the P-38 is described in AHT, and I have read similar descriptions in other sources.
The P-38 was a large heavy fighter not suited for quick "snap" or "slam-bang" manuevers, and had a particularly slow initial response in roll due to a high lateral inertia characteristic. The problem was a slow start into a roll and thus an inability to switch quickly from one attitude to another, as in reversing from a turn in one direction to one in another. As one pilot said "It was disconcerting to have a fighter barreling in on you, crank the wheel over hard, and just have the P-38 sit there. Then after it slowly rolled the first five to ten degrees of bank it would turn quickly. The hesitation was sweat-producing. Many combat losses, particularly in North Africa, were attributed to this creaky initial rate of roll. Another pilot noted "The first ten degree's of bank came very slow."
Now, Im sure someone will jump in here and claim that because the L had hydraulic boosted ailerons, that is correct. Well.. that person would be wrong (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
Power boosted ailerons, introduced the same time as dive recovery flaps, gave the P-38 pilot a lot more "muscle" to improve roll characteristics at high speeds, but did nothing to improve them at low to moderate speeds where maximum roll performance was dependent on full aileron deflection, instead of pilot effort
I personally talked to a WWII P-38 pilot on this issue when I toured the NASM Garber Facility in Washington DC. He had flown the F, early J, and the L model. When asked how much the boosted ailerons helped, his exact words were with a chuckle "Not much".
Now in AH, the P-38 has very little feel of inertia and in my opinon actually has a quicker roll than some other planes like the N1K2.
Couple that with the low induced drag, and this bird will do an amazing series of flat scissors on the deck. It should be horrible at this.
The only weakness I could find in the P-38 last night was its large size, and that it had inheirited the infamous "glass tail" of the WB's P-38.
To be honest, this plane right now literally scares me more than any other plane in the game. Moderately fast, good climber, turns forever, accelerates quickly, and it has good guns with alot of ammo. I can't find a weak point with its performance.
MUCH more deadly than the F4U-1C ever was.
Will do some more hard testing on climb & speed later.
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Vermillion
**MOL**, Men of Leisure,
"Real Men fly Radials, Nancy Boys fly Spitfires"
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Good post Verm. I hope HTC revisits this FM before too many people get hooked like in the old WB days.
My first fight in a P-38 was against another P-38, merging at about 15K. We kept doing vertical scissors all the way down to the ground, and even though I was nearing blackout on most turns, I never got below 220 mph. We finally HO'd at ground level, he got my port engine then augered into a hill. Even with 1 engine dead and fresh from a turnfight I was at 210mph at the moment he augered.
The most striking thing during the scissors was that we would end up D1.2 apart at the outer point of the turns before zooming back in toward each other. It really seemed more like 2 F-86's fighting. A well flown P-38 will be untouchable, like in old WB.
It needs some roll inertia and some more E bleed, as you say.
--ra--
[This message has been edited by ra (edited 03-01-2000).]
[This message has been edited by ra (edited 03-01-2000).]
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I was only able to fly for about 30 minutes last night but one thing I was amazed at when flying the P-38 was the lack of the stall sound going off in maneuvers.
I know thats not much to go by. Untill you take inot account I suck as a combat pilot. (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
-Westy
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LOL.. yah I saw some amazing stuff happinin last night w/ the p38's.. truly amazing. (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)
Brings back fond memories. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
Hang
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The E retention is a bit too good right now. Check the stall speed, 125 mph! It currently has a better turn rate than anything else, although the radius is pretty large, second only to the 190!
With regards to zoom ability. The P-38 should excel at high altitudes where the TAS is highest. A zoom from 400-200 TAS at that height = 4000'.
If you watch Jeff Ethel's P-38 video, he starts centering the ailerons about 180 degrees before the roll ends, albeit slowly.
I did a moment of roll inertia calc based on the data in AHT. Maybe Pyro could compare to his figure?
MoIroll (final value is metric):
Wing (52' x 6.3'; 1860 lbs): 18000
Booms (8' from centerline, 9000 lbs): 24300
Total (neglecting fuel in wings): 42300
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Prefacing this by saying that I don't play AH since it moved out of Beta, all I can say it what I've felt about AH all along... it's WB 1.11 all over again.
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SnakeEyes
o-o-o-
=4th Fighter Group=
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Snake,
...and did WB 1.1 develop into your favorite game?
(http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)
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Snake,
...and did WB 1.1 develop into your favorite game?
Touche!
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jochen
Geschwaderkommodore
Jagdgeschwader 2 'Richthofen' (http://personal.inet.fi/cool/jan.nousiainen/JG2) (Warbirds)
jochen
JG 2 'Richthofen' (Aces High)
If you ever get across the sea to England,
Then maybe at the closing of the day
The bars will all be serving German lager
Which means we won the war - hip hip hooray!
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WellS:
in regards of Zoom or Climb capablity TAS doesn't help ya any .. CAS (Indicated air speed corrected for installation errors) is the main factor .. because your wing will stall at always the same CAS even thou your TAS will be much higher at high altitude.
I see that you have the least drag at high altitude and therfore the highest TAS but you'll stall out before you can use those extra knots.
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(http://members.aon.at/duckwing6/dw601.gif)
Phillip "Duckwing6" Artweger
Flight Officer "E" Flight
Skeleton Crew (http://www.picknowl.com.au/homepages/oneshot/main.htm)
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heh
turn it into the sims worst flying aircraft is what it sounds like we need here (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
I will still fly it even if that does happen.
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Ol' SnakeEyes,
What you fishing for now? I do believe you might want to try another 'lake', since the fish here are actually well fed
(http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
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leonid, Komandir
5 GIAP VVS RKKA (http://www.adamfive.com/guerrero)
"Our cause is just. The enemy will be crushed. Victory will be ours."
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Duckwing - Actually TAS does help you because it determines the amount of kinetic energy that you can use to zoom. I think what Wells means is that the P-38L is the king of power-loading at higher altitudes, so it should zoom better than the others up in the nether regions.
Vermillion - About the transient roll response, remember that the roll acceleration (degrees/sec^2) is proportional to the rolling moment from the ailerons divided by the roll inertia. Due to the hydraulic assist, at high speeds the P-38L rolling moments are enormous as are the damping moments which slow down the roll rate once the ailerons are neutralized.
So P-38L roll acceleration and decceleration should be more rapid than many planes at high speeds. But at low speeds it should perform poorly in this regard.
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300 mph example:
Wing Area occupied by each aileron: 3.7 sqm
Change in lift coefficient with full aileron deflection: ~0.5
Distance from centerline: ~6.0m'
Roll torque @ 300 mph IAS: 245000 N.m
//divide by Moment of Inertia to get acceleration//
a = 5.8 rad/sec/sec (initial)
a(average) ~ 2.9 rad/sec/sec
Maximum roll rate @ 300 mph ~ 1.4 rad/sec
Therefore, it would take about 0.48s to reach maximum roll rate, in which the plane would roll through about 19 degrees. Upon centering the ailerons, roll would stop in about 1/2 the time.
Comparison to 100 and 200 mph speeds
100 mph: t~1.5s / 19 degrees
200 mph: t~0.72s / 19 degrees
Notice that the plane will roll through the same number of degrees in order to get into and out of maximum roll rate. It just takes different amounts of time to do so at different speeds.
You could test it in AH at say 200 mph (the slower the better). Time one roll from a standing start. Then do a complete roll before timing the second one at max roll rate. Try to keep speed as close to what you started at as possible throughout the maneuver. You should get about 5% difference in times. I'll do some testing and see what happens. Where's Popeye? (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
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Flew the -38 for the first time in combat last night. I have a few observations:
This airplane appears to have very low induced drag, helping its amazing E-retaining abilities. Its deceleration in sustained high rate turns is quite low (both vertical and horizontal). In one fight, I lost an engine and was still able to maintain a 190 mph horizontal scissors on the deck with another -38 that had two engines turning. (One snapshot to his port boom was all it took to end the fight.) At first I thought it was all the air blowing over the wings from the two engines but single engine operation afforded only slightly reduced acceleration capabilities and possibly a smaller turn radius.
Glide ratio with engines out and 25% fuel, no stores in clean config is just about 10:1 at 12k improving to 11:1 at 2k. No problems reaching any base if you have 10,000 feet over friendly territory with no fuel or dead engines.
Rudder affects the P-38 much different than any other airplane. There is less overall yaw and far less drag from this three boomed twin ruddered airplane than any of the single rudder, one fuselage fighters. The P-38 seems to actually sidestep/skid more than other airplanes especially with opposite aileron to keep it level. The airplane will actually climb AND accelerate with full rudder deflection and opposite aileron! It does not decelerate at idle in a glide with these surfaces deflected the way other airplanes will.
With two props, we should see twice as much prop drag when at idle and it doesn't feel like this is happening. Not sure if its modeled into any of the FM's yet, however.
This airplane is the king of STOL! A clean light config will allow no flap/no wep liftoffs before the first runway intersection. Fully loaded with 2000lbs of bombs and 10 rockets, its possible to lift off with no flaps/no wep before the second runway intersection.
The guns have a definate vertical convergence with the 20mm shells dropping down rapidly below the .50's once past the convergence point.
The centerline pack of four .50's offers the ability to routinely obtain 800yard+ concentrated hits since there is no horizontal convergence. Received a tail shot and damage (engine out) at d1.1 from a -38 that fired an 15+ second spray and pray volley. (Don't these sim guns melt? (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif) ) Head on shots are a breeze even at max range.
Questions that I have for Pyro/Nate/HiTech:
Does a disabled engine automatically feather the prop?
Is it possible to make the prop spinners rounder to prevent their incessant blinking?
How is damage to the exposed turbo-superchargers modeled? Being on the top of the booms, they seem very susceptable to damage from all but underside shots.
MiG
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"Is it possible to make the prop spinners rounder to prevent their incessant blinking?"
I'm glad someone mentioned that. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif) The other stuff too - for the most part already had been mentioned in other posts. But this one item bugged me to no end looking out of the cockpit last night.
-Westy
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Even "post patch" it still has unnatural E retention (lack of induced drag) in comparison to the rest of the planeset.
I don't think the roll has changed at all though (http://bbs.hitechcreations.com/smf/Smileys/default/frown.gif) This should be the biggest weakness of the P-38 series, and its not even a minor inconvience in AH.
Nice Observations and work Wells and Mig Eater.
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Vermillion
**MOL**, Men of Leisure
(http://web.mountain.net/~arringto/pics/yak3.jpg)
[This message has been edited by Vermillion (edited 03-02-2000).]
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Vermillion, it seems to have plenty of roll delay at slow speeds. At higher speeds it should and does roll real nice due to the hydraulics.
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Without the hydraulics, I think the roll maxed out at 250 mph or so...not too impressive. With the aileron boost, you can keep rolling faster right up through 600 mph if ya want! You gotta watch that you don't pull max G's and roll at same time over 250 mph, could break a wing off!
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well whatever the case the 38 seems to matchup well with the other planes
The p38l has 1121 kills and has been killed 1171 times.
The F4U-1C has 627 kills and has been killed 309 times.
The P-51D has 346 kills and has been killed 233 times.
The p38l has 83 kills and has been killed 169 times against the F4U-1C
The p38l has 75 kills and has been killed 109 times against the P-51D
The p38l has 127 kills and has been killed 137 times against the Spitfire Mk IX
The p38l has 19 kills and has been killed 21 times against the Bf 109G-6
The p38l has 46 kills and has been killed 49 times against the C.205
The p38l has 34 kills and has been killed 23 times against the Fw 190A-8
The p38l has 44 kills and has been killed 47 times against the N1K2
The p38l has 10 kills and has been killed 21 times against the La-5FN
I'm just not seeing the effects of these so called problems in the stats (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
in actual combat it performs as expected and as it should. it outaccelerates, climbs, and turns, and goes fast and has nice guns.
(fangs reared and cornered Citabria valiantly defends his lightning from claims of uberness)
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btw the lightning in AH fully compresses at 500 ias I guess as a way to simulate having dive flaps.
have you guys bothered to test the stall model? have you seen how violent it is and how spins are totally unrecoverable without an experienced pilot at the controls?
oh I guess were just looking for things to make worse on the 38 so our own rides will be better.
well relax cause the p38 isnt hard to kill
sorry I guess I'm ranting again (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
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Citabr, (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif) I think you will find that most of the guys that have posted in this thread pick on all the planes that they find a problem with. Not just the ones they don't like or don't pilot.
Me, I fly the Pony, and just last week was putting up a bug report on it ordinance loadouts (carries too many rockets, while carrying bombs).
We just all want the planes to be as close as possible to what they really were. Thats what seperates a simulation, from an arcade game. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
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Vermillion
**MOL**, Men of Leisure
(http://web.mountain.net/~arringto/pics/yak3.jpg)
[This message has been edited by Vermillion (edited 03-03-2000).]
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What people may not be aware of is that the P-38 had a very high aspect ratio, probably only to be exceeded by the Ta-152. This results in significantly reduced induced drag. Frankly, I'm not surprised by it E-retaining capabilities.
Incidently, aspect ratio is:
(wingspan * wingspan) / wing area
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leonid, Komandir
5 GIAP VVS RKKA (http://www.adamfive.com/guerrero)
"Our cause is just. The enemy will be crushed. Victory will be ours."
[This message has been edited by leonid (edited 03-03-2000).]
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leonid, that is not the whole truth!
the induced drag coeffizient Cdi is
Cdi= Cl^2 / pi*AR
Cl = lift coeff.
AR = aspect ratio
a high AR is good for a low induced drag, but more important is a low Cl (C_lift)value.
And Cl is for a constant horzontal flight proportional to the wingloading
Now letīs have a look to the acīs:
weight P38L : 17500lb
weight 109G10: 6800lb
wing area P38: 328 ft^2
wing area G10: 177 ft^2
wingspan P38 : 52ft
wingspan G10 : 33ft
wingloading P38: 53 lb/ft^2
wingloading G10: 39 lb/ft^2
ratio: 1.36
Ar P38: 8.2
AR G10: 6
ratio. 1.36 (ups, almost the same:-))
Powerloading pounds/horsepower
P38: 5.5 lb/hp
G10: 3.7 lb/hp
ratio 1.48
ok, the P38 has a better AR, but at the same time a worse wingloading. And wingloading has a (^2) in the formula for the Cdi :-)
So the induced drag coeffizient of a P38 is imo very high
Hope i didnīt make some mistakes with the formulas:-)
Now letīs see how a p38 performs in AH.
gliding: cut off the enignes in 6000ft, autospeed 160. note neg. climbrate in 3000ft.
P38L : -1300ft /min
G10 : -2000ft /min
Hell, a 17500lb ac glides so much better than a 6800lb fighter.
Then i tried a constant 4G turn, full cirlce near the ground (360° turn), starting from 400mph
after that full circle the remaining speed was:
P38: 285mph
G10: 230mph
sorry, P38 is still too good imo
niklas
[This message has been edited by niklas (edited 03-03-2000).]
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Induced drag for 4G 300 mph
P-38L (17500 lbs) - 2500 lbs
109G10 (7400 lbs) - 1167 lbs
You're right Niklas, but...
Speed loss/time (acceleration) @ 300 mph, 4G's, g = 32 ft/sec/sec
P-38L - 2500g / 17500 = -4.57 ft/sec/sec
109G10 - 1167g / 7400 = -5.05 ft/sec/sec
The 109 should slow faster! As it slows, it needs more Cl to make the 4G's and it's drag goes up even more in proportion with the P-38.
Glide performance is the same relationship as it's also a measure of deceleration for given speed and G load.
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Ok Wells let me see if I am getting this straight.
Lets assume that the G10 induced drag in AH is correct.
By your numbers of -4.57 and -5.05, then ratio these, the P-38L should have 90.5% of the drag of the G10. Ok I can see that.
Now, in your last sentence you indicated that the drag you calculated is a linear relationship to the glide slope test that Niklas did.
But when we look at the ratio of glideslope , -1,300 ft/min to -2,000 ft/min , this will produce a ratio relationship of 65%.
So am I correct when I assume that, this means the P-38L only has 65% of the drag that the G10 has in Aces High, instead of the 90% historical?
Realize I am trying to remember these relationships in my head from work, and I may be confusing too many issues and variables here including the lack of parasitic drag. But even still I would think that the P-38L should have more parasitic drag than the G10 would *shrugs*.
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Vermillion
**MOL**, Men of Leisure
(http://web.mountain.net/~arringto/pics/yak3.jpg)
[This message has been edited by Vermillion (edited 03-03-2000).]
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Niklas, you are correct. I pooched my last calculation because I forgot to take a higher Cl into account. My bad, I'll get it fixed. Thanks for pointing it out in a way that made me realize what happened.
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Doug "Pyro" Balmos
HiTech Creations
"If it's stupid but works, it's not stupid."
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By your numbers of -4.57 and -5.05, then ratio these, the P-38L
should have 90.5% of the drag of the G10. Ok I can see that.
Not drag, acceleration. You can see that the P-38 has much more drag than the 109, as Niklas pointed out.
Now, in your last sentence you indicated that the drag you calculated
is a linear relationship to the glide slope test that Niklas did.
Acceleration is directly related to climb/glide rates. I don't really know what the planes weigh in AH but I recall Pyro saying that it was 'about' 7400 lbs. If I do the calc for 6800 lbs as in Niklas' post, it looks like this...
300 mph, 4G's (109G10)
a = -4.64 ft/sec/sec
, much more comparable to the P-38. It looks that maybe the 109G-10 could be even heavier than 7400 lbs, 7700-7800 maybe? Pyro?
Niklas, were you carrying a drop tank or gondolas or anything?
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Citabr:
"btw the lightning in AH fully compresses at 500 ias I guess as a way to simulate having dive flaps"
You are confusing compressibility with high control forces caused by high dynamic pressure.
The posted dive limit was Mach 0.65. Above Mach 0.74 it should suffer uncontrollable nose-down pitching and vibration. From AHT: "if the aircraft hung together control could finally be re-established in the warmer denser air of lower altitude."
Of course the L model had dive flaps which could prevent this from happening, but the flaps did this mainly by slowing the plane down in a dive.
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wells, donīt you think 7400lb is a little bit too much weight for a G10? Nowarra says about 3400kg / 6800lb. Is it possible that your source added the weight for an external fuel tank?
Youīre right that the slower the plane getīs, the harder i have to pull to get 4G. I know that problem, nevertheless you can see the difference between those planes.
ok, induced drag is maybe a little bit lower for the P38. A little bit. But you canīt look only at a moment, at the moment of 300mph. While drag slows your plane down, your engine gives energy back, right? and the G10 has a much better powerloading.
Add the force of the engine to the negative force of drag at 300mph and iīm absolutly sure myself that the new deceleration is bigger for the P38.
niklas
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Where are you getting your CL data from??
Is it specific to the P-38L?
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ups, while i was writing my posting, some new postings did appear (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
so letīs wait for the next patch (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
niklas out
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Niklas, 3400 kg is 7490 lbs (454 grams/ pound).
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F4UDOA,
The Cl comes from the lift equation
L = Cl * WA * V * V * density / 2
rearranging for sea level
Cl = 391 L / (WA * V^2)
V is in MPH and WA (wing area) is in square feet. The Lift force is in pounds. The constant 391 works out the units and is only good for sea level calcs...makes things a bit easier. Note, that L = weight * G factor.
The drag equation is the same as lift, only Cl is replaced with Cd.
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Niklas, let's take it a step further and factor in thrust and zero-lift drag at different speeds, 150, 200, 250, 300, 350 mph
I'll assume that 350 mph is the top speed of both planes at sea level(not far off).
Starting with max speed, so I can figure the Cdo where T = D.
109G10 (1800 hp)/P-38L (3200 hp)
350 ~ 1700 lbs/3040 lbs
Cdo (using wing area) ~ 0.031/0.030
f (equivalent flat plate area) ~ 5.4/9.8
(Thrust, Zero-lift drag)
300 mph ~ 109(1850, 1250)/ P38(3330, 2230)
250 mph ~ 109(2170, 870)/ P38(3930, 1550)
200 mph ~ 109(2590, 560)/ P38(4760, 990)
150 mph ~ 109(3040, 310)/ P38(5820, 560)
Excess thrust = T - ZLD
Plane 109 / P38
300 mph ~ 600/1100
250 mph ~ 1300/2380
200 mph ~ 2030/3770
150 mph ~ 2730/5260
Acceleration due to excess thrust(ft/sec^2)
Plane 109/P38
300 mph ~ 2.59 / 2.01
250 mph ~ 5.62 / 4.35
200 mph ~ 8.78 / 6.89
150 mph ~ 11.8 / 9.62
So the 109 should get an advantage here. For the 300 mph 4G example, there's just enough in the 109 to overcome it's disadvantage and the planes are about equal. When pulling max G's, the advantage goes to the P-38 above about 250 mph.
Personally, I didn't notice any change in the P-38 for patch 2, even though Pyro said he made a big change to induced drag. Sustained turn speed was about the same as in patch 1 at 175 mph.
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> Of course the L model had dive flaps which could prevent this from happening, but the flaps did this mainly by slowing the plane down in a dive.
Hmmmm, it is my understanding that the dive flaps had more to do with increasing lift and controlling the boundary layer air flow under the wings than by slowing the plane down.
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Originally posted by Gator:
Hmmmm, it is my understanding that the dive flaps had more to do with increasing lift and controlling the boundary layer air flow under the wings than by slowing the plane down.
From my recent research this is my understanding also.
The compressability problem had to do with the speed of air passing over the wings. Even though the A/C was below Mach speed the airflow passing over the wings was above Mach. Air at Mach speed reacts more like water than air. This caused the center of lift for the wing to be shifted rearward, forcing the nose down. This effect was called "Mach Tuck".
The first batch of "Dive Recovery Flaps", "Dive Flaps" or "Compressabilty Flaps" were fitted to the P-38J (P-38J-25). They were fitted to the lower wing outboard of the tailbooms and were 4' 10" long. From the picture that I have, I am guessing the flaps were about 3 to 5" wide. Electricaly operated by a button inside the cockpit, the flaps would deploy or retract in about 1 second. Full open deployment was 35 degrees.
The purpose of the flaps was not to act as a "Dive Brake", but to alter the air flow over the lower surface of the wing. Altering the air flow over the wings to shift the wings center of lift.
Actually, the flaps only delayed compressability and did not prevent its occurance. They simply raised the speed for which it happened. My guess is this speed was high enough to not be an issue later on.
Tony LeVier, a Lockheed test pilot at the time wrote.
The dive flaps did three things (All positive):
1) They produced a slight stalling moment.
2) They created some added drag to help slow the plane down.
3)The produced a slight gain in lift of (the) wing area affected by (the) dive flaps.
(LOL I have the same problem with forgetting to use "the's")
Tony also went on to say that the flaps for all intents and purposed fixed the compressabiliy problem.
Now a P-38 with dive flaps could perform Split-S manuvers with ease. Mixed with the hydraulically boosted ailerons, it became truly the dogfighter that it was intended to be.
The silly part to all this was that the flaps had been tested as early as Feb 1943. However; the paradigme mind set was that it was the ussual design of the "Twin Boom Tail" that was causing the problem. Not high speed airflow over the wings.
Who knows what history might have written about the P-38 had it beaten the P-51 to the ETO with the issue of compressability solved.
BTW, can any one explain to me what is meant by the expression "They produced a slight stalling moment"? Thanks! (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
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Mino
The Wrecking Crew
Trainer
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first, please excuse my mistake that i didnīt convert correctly lb <>kg (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif) Again, after the failure of the satellite, a disastrous error due to the convertion of metric to us-units
wells, there is a difference beween patch 1 and 2. At least i get about -1550ft/min now, and 250mph in the 4G test. Still very good i think, but not too good.
For the 1700lb~350mph, did you substract the induced drag? Did you substract later for the thrust also the induced drag? With F=P/v i get higher values for the thrust.
I tried a 4G test for 180° turn, starting from 300mph. P38 is better, comes around at 220mph G10 at 200mph.
"When pulling max G's, the advantage goes to the P-38 above about 250 mph"
So, friends of the P38, here is the ultimativ tactic instruction if you have a lot of speed and you have a fight with a 109 : Pull as hard as you can at your stick to get max. Gīs and withit the advantage (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)
niklas
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Mino, I think the engine reliability and the maintenance and fuel expenses would have still kept the P-38 from supplanting the P-51D.
The only dimension I can find for the dive flap span is that 58" figure. From eyeballing them in person I would estimate the chord at about 18".
[This message has been edited by funked (edited 03-05-2000).]
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Leonid and others who think I was attempting to bait... not so. I'm merely questioning why so many of the AH aircraft seem to experience so many same flight model problems that Warbirds had? You'd think that HTC would be more able to account for those issues, given previous experiences...
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SnakeEyes
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=4th Fighter Group=
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SnakeEyes:
"You'd think that HTC would be more able to account for those issues"
SnakeEyes, you might have noticed that HTC released two patches within 24 hours to correct mathematical errors in the P-38 FM parameters. They are more than able to account for those issues. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
"I'm merely questioning why so many of the AH aircraft seem to experience so many same flight model problems that Warbirds had?"
What are those problems exactly? What I'm noticing is that AH has so FEW of the same flight model problems that Warbirds still HAS. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
[This message has been edited by funked (edited 03-06-2000).]
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Originally posted by SnakeEyes:
Leonid and others who think I was attempting to bait... not so. I'm merely questioning why so many of the AH aircraft seem to experience so many same flight model problems that Warbirds had? You'd think that HTC would be more able to account for those issues, given previous experiences...
Considering the amount of work these folks pump out, I for one am willing to cut them a little slack when a value in an equation is found to be a little off.
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Granted, I don't presume to speak with authority about the physics of it all... you guys know far about that stuff than I do.
However, it seems that I've heard the same complaints regarding performance at altitude (for many aircraft), the P38 not bleeding E like they should (I assume this is the issue fixed?), complaints in general about Otto (ground based), and I found that the P51 seemed to have a bouncy nose that reminded me very much of WB 1.1x. I also found the Beta to be very microwarpy... of course, alot of that is just the nature of the Net IMO.
Granted, I stopped playing after Beta... so I don't know how many of these were fixed (I understand you guys now have flap/gear limits and such).
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SnakeEyes
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=4th Fighter Group=
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I can only speak from my perspective, so here goes:
Nose bounce in AH51 vs. WB51- not even close. If your controls are set up properly the 51 flies as if on rails. You will see it drift up or down based on trim, but that is what is should do.
Warp WB vs. AH- again, no contest. We all know well the microwarp escape plan patented by the P38 and 190 in WB. It just doesn't happen here (to me, anyway) the way it did there. People do warp (find any online game that doesn't) but the effects aren't nearly as pronounced.
Airframe limits have long since been added, as well as speed restrictions on flap/gear deployment. There is no appreciable difference in this area.
Control was crisper to some extent in WB, but I'm not sure this is necessarily accurate. YMMV.
One guy's opinion! I'd say you need to activate the account and test a current version before you pass judgement. (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
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Hehe... only 3 things would get me to consider that:
1) Latewar uberbirds (F8F, Ta152 [Nice book VERM], Tempest, P51H, etc).
2) A Mac version (several members of the WB squad I'm in fly Macs).
3) WB totally disintegrates/AH is proven to be completely superior. Right now, even if the FMs truly are superior (seems like eye of the beholder these days), I found the gameplay to be lacking.
PS - I flew in AH off and on right up to the end of the Beta, and I'm not at all convinced that the smoothing code here is better. In fact, my experiences (using 3 different connections) is that it was worse.
Not a rip, just one guy's opin...
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SnakeEyes
o-o-o-
=4th Fighter Group=
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> Mino, I think the engine reliability and the maintenance and fuel expenses would have still kept the P-38 from supplanting the P-51D.
I agree with the conclusion that it is unlikely the P-38 would have supplanted the P-51D, but for different reasons.
While Kelly Johnson proposed replacing the turbo-supercharged Allisons with Merlins and mechanical superchargers to solve the problems with the poor quality British fuels, the Merlins were already in demand for other fighters and unavailable for use in the P-38.
With only so many P-38's to go around, it's not surprising that with the high altitude problems with the turbo-supercharged Allisons and the British fuels, the demands for P-38's in the Pacific, by the Fifteenth in Italy, and for low-altitude work with the Ninth that the Eighth would go with the Mustang.
Then add in the fact that the Lightning was more expensive, could not be mass produced as easily, was more difficult to maintain and more difficult to fly for the average pilot than a single engine fighter.
One of the amazing things, to me, about the large numbers of P-38's built is that it was not originally designed for mass production and was originally, as Martin Caidin says, essentially a hand-made machine since Lockheed was led to believe that the Air Corps would buy no more than fifty!
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> were 4' 10" long. From the picture that I have, I am guessing the flaps were about 3 to 5" wide.
Mino, FWIW I noticed in Johnsen's Warbird Tech for the P-38 that you earlier mentioned you had that on p. 35 it's stated that "The dive recovery flaps were 58 inches in span, and when actuated protruded a maximum of five and a half inches beneath the bottom surface of the wing." He lists a draft of Lockheed Lightning Design Analysis, July 1944, as the source for these dimensions.
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Thanks Gator! 2 x 58 x 5.5 = 638 sq. in. which is pretty bloody small compared to the normal frontal area. Not much drag probably.