Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: SectorNine50 on August 01, 2008, 11:04:21 PM
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I'll probably get some heat from the F4U pilots for asking this... but from what I've read of the seagull wing design on the F4U, at low speeds, this plane should be very, very unstable (in a turn in particular). Now from what I've flown in and against, I don't really notice this in-game. I was wondering if anyone else has felt or noticed that maybe the low-speed characteristics of the F4U are a little over modeled?
(Please note, this is not me complaining, I'm simply curious.)
-Sector95
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Search button is your friend. Been discussed quite frequently.
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Ah damn. The one time I don't do a search... :cry
Thanks I'll do a search.
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There is much propaganda surrounding that too.
Most of the low-speed handling issues were experienced in the F4U-1.. the version that lacked the stall strip on the right hand wing. Our F4U-1, however, has the stall strip modeled so we have the same handling as the other F4U's which may be an error.
Also, the proper landing procedure in real life was to land and stall right before you hit the deck so you wouldn't bounce. In AHII, the whole bouncy thing isn't really modeled very well.. i.e. planes don't respond to landing as realistically as possible. Not that it matters.. its a flight sim.
In AHII, its much easier to land so we can land at higher speeds. Once the hook catches, you're safe.
That wasn't always so in real life.
The cable would stretch, giving the pilot more of a reason to be as slow as possible. If you try the real life approach, flying at very near stall speeds so that the stall buzzer is loud, but you're not buffeting, no combat trim, eventually your nose will start to fall. Lots of F4U pilots made the mistake of pulling up and firewalling the throttle. Try this in AH and you will actually spin to the left. With combat trim on, your plane will trim itself with throttle input so you won't really feel it with CT.
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The F4U's low-speed stall behavior IS mellowed a bit, however this is also true of ALL planes in the set. However based on a number of conversations the historical behavior is also exaggerated to a degree. MANY high-performance fighter aircraft during the war had just as bad, if not NASTIER, departure behavior than the F4U.
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One thing that seems odd given their RL reputations is that in AH the F4U's low speed stability is better than the F6F's.
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One thing that seems odd given their RL reputations is that in AH the F4U's low speed stability is better than the F6F's.
really? it seems like if im on the dec i can normally kill a hog with my kitty :D
unless its SHawks CHog
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This has been beaten to death, but imho F4U's post patch low speed handling is too gamey and over modeled. Given the size,wing area/design and power/weight ratio of the aircraft. Being able to dump flaps and float about like a zeke is one thing. But then being able to lower and raise gear within secs to further increase flight performance at lower speeds while still maintaining the ability to float about like a zeke is gamey. And taking advantage of the flight model imho.
Add this to the C-Hog and it's become the best prop ride in the game post patch.
<S>...-Gixer
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Add this to the C-Hog and it's become the best prop ride in the game post patch.
Ya, it's the new LA7. The Crutch of the LW arenas
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One thing that seems odd given their RL reputations is that in AH the F4U's low speed stability is better than the F6F's.
didn't Widewing test and psot this information in a thread awhile back, it seems so dejavu to me.......
some have psoted the F4U has become more uber than the spitfires etc...... only changes I have noticed is the Manual Trimming out speeds have increased roughly 15 to 20/25 mph and with the most recent update ( again confimred by Widewing ) is you will get better response turning to the right if you back off the throttle a bit to negate the Torque of the engine / engine rotation....... beyond that It still flys nearly the same for me as it always has......
the dang Gunsite/bore site could be englarged a bit , be nice if it was a lil bigger more along the lines of the other aircraft....and that dang head armor is /looks way much larger in the game than it does in real life ......
change it or complain enough that they change it, and I will still figure out how to make it go vertical with less than 100 ias and still figure out how to float it around at or below 39 ias .......that is part of the fun factor with Aces High.staying on top of what your plane platform is capable of doing......
and why on earth would someone want to waste their time dropping and raising the Gear is beyond me...really not necessary...
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This has been beaten to death, but imho F4U's post patch low speed handling is too gamey and over modeled. Given the size,wing area/design and power/weight ratio of the aircraft. Being able to dump flaps and float about like a zeke is one thing. But then being able to lower and raise gear within secs to further increase flight performance at lower speeds while still maintaining the ability to float about like a zeke is gamey. And taking advantage of the flight model imho.
Add this to the C-Hog and it's become the best prop ride in the game post patch.
<S>...-Gixer
I for one have never understood the whole "F4U gear increasing its performance" thing. When I drop it, it slows me down. That's about all I notice. My understanding is that that's what it's supposed to do... What effect is it rumored to have?
I do admit though, that I never use it while fighting so I could be missing something. In about 1 fight out of 500 I'll use it as a last-ditch effort to prevent an overshoot, but otherwise I don't even give it a second thought until it's time to land.
We have had many, many pages of writing about the F4U's low speed handling. Has anything conclusive come from it? Something that HTC could/would/should use to adjust the flight model? Would it be limited to the F4U? Or a basic change to the way lift/drag or whatever effects everyone? Is the "problem" limited to the F4U series? Do Yaks, Spits, 109's or whatever fly 100% correct in all respects? Is it possible that they aren't correct either? Or even as correct as the F4U for that matter? Maybe they're not quite right either, but the witch hunt hasn't progressed to them yet?
I'm NOT defending the way the F4U or any other plane is modeled. I can't, as I simply don't know. Having seen many arguments from both "sides", I still stay neutral, as they both have good, valid points. And truthfully I don't care all that much. I'd only quit flying the F4U if it was removed from the game. And if they did I'd probably leave the game, as none of the other planes spark all that much interest from me. Any flight model change I'd simply adjust to. I'd like all the models to be as accurate as possible, but I think they still need to be flyable for average "Joes" off the street. We "know" there are certain concessions made to reality as it is- throttle management, combat trim, etc... Are there others we aren't so sure about?
MtnMan
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TC,
I've been asking for the gunsight to be enlarged about once or twice a month in the Wishlist since before the Hogs were updated. The bubble-top Hogs ESPECIALLY it needs to be doubled in size (per calculations I've done using the full--not the version that just uses the rings, but the extended cross--Mk.8 gunsight). Using the Mk.8 site a 190D's wintips should be SLIGHTLY larger than the outer ring at 200yds. In the game this occurs at 400.
I never use my landing gear in a turn-fight, ESPECIALLY if there's other cons around. I only ever use them in combat under two conditions: dive-bombing and my initial dive into a fight if I'm attacking a con significantly lower than me to control my dive speed.
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Turn off your stall limiter, then jerk it in a hard turn. You'll see what everyone's talking about.
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I have no problem controlling a f4u, f4u-1 for that matter.
The landing gear trick should only be used for slowing down quickly or like saxman said, dive bombing or droping down on a target to prevent overshoot. Should never be deployed for any other reason but landing. Doesn't help in turning at all, in fact it hurts its turning performance.
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I have no problem controlling a f4u, f4u-1 for that matter.
The landing gear trick should only be used for slowing down quickly or like saxman said, dive bombing or droping down on a target to prevent overshoot. Should never be deployed for any other reason but landing. Doesn't help in turning at all, in fact it hurts its turning performance.
Shh, dont tell them that :)
I got in a 1 vs. 1 in the DA with another F4U. We had been going at it for so long, I landed, cut my engine, he swooped right past me and from the ground, shot him down. :rofl :rofl
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Accurate or not, the low speed handling of the F4U is a headache for anyone facing the wrong end of it. Some of you advanced F4U sticks do a little trick where you out-turn a faster attacker (no big deal), and when the attacker goes into a high-yo-yo you reverse in the vertical at about 100ias guns blazing before the attacker gets his nose around. It's an amazing way to neutralize an attacker's energy advantage, and so it always makes me cautious about trying to trade energy for angles against a good F4U pilot. Fwiw, I don't know of any other aircraft in the game that can pull the same maneuver so well.
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Here are the links from a recent post I made, I used some of the most knowledgeable people in AH, to quote.
It isn't the gear that makes the thing a ufo, its the low speed handling.
Ok, I like the F4U very much, but it is entirely too stable at low speeds. More so than the F6F, which set the standard for carrier fighter stability around the boat. You can fly it down to 60 mph, nose high and cob the power with not a hint of instability. Historically, it's wrong, period. I've discussed this with a gentleman who flew the F4U-4 and F4U-5. When I described the low-speed handling behavior he wrote back and said, "if I had attempted what you described, I wouldn't be here to discuss it with you."
In a discussion with a local FG-1D owner, he described low speed, high power handling as "like a fat girl on a surfboard."
As far as I can remember, the F4U was always good with flaps out. After the drag model update it went from just good to absolutely ridiculous. Ditto for the 109s to lesser degree.
Planes that suffered from the drag model update include the Ki-61 and P-51 to name the most obvious.
Now clearly, the FM is a constantly evolving creature. Thus, we can expect changes and tweaks as the game move forward.
My regards,
Widewing
There was a warbird pilot who owned an F4U and flew AH...I was talking to him and he'd just sold his F4U. I asked him why and he said he was scared every time he flew it. He called it totally unforgiving of any error on takeoff or landing....
All the people that I know that fly the Corsair say keep it fast. Don't screw around low and slow, and don't you dare stall it.
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One thing that seems odd given their RL reputations is that in AH the F4U's low speed stability is better than the F6F's.
Need to disagree. While the F4U's nasty stall has been neutered, the F6 is, IMO, one of the most stable planes in the set.
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I for one have never understood the whole "F4U gear increasing its performance" thing. When I drop it, it slows me down. That's about all I notice. My understanding is that that's what it's supposed to do... What effect is it rumored to have?
I do admit though, that I never use it while fighting so I could be missing something. In about 1 fight out of 500 I'll use it as a last-ditch effort to prevent an overshoot, but otherwise I don't even give it a second thought until it's time to land.
We have had many, many pages of writing about the F4U's low speed handling. Has anything conclusive come from it? Something that HTC could/would/should use to adjust the flight model? Would it be limited to the F4U? Or a basic change to the way lift/drag or whatever effects everyone? Is the "problem" limited to the F4U series? Do Yaks, Spits, 109's or whatever fly 100% correct in all respects? Is it possible that they aren't correct either? Or even as correct as the F4U for that matter? Maybe they're not quite right either, but the witch hunt hasn't progressed to them yet?
I'm NOT defending the way the F4U or any other plane is modeled. I can't, as I simply don't know. Having seen many arguments from both "sides", I still stay neutral, as they both have good, valid points. And truthfully I don't care all that much. I'd only quit flying the F4U if it was removed from the game. And if they did I'd probably leave the game, as none of the other planes spark all that much interest from me. Any flight model change I'd simply adjust to. I'd like all the models to be as accurate as possible, but I think they still need to be flyable for average "Joes" off the street. We "know" there are certain concessions made to reality as it is- throttle management, combat trim, etc... Are there others we aren't so sure about?
MtnMan
Amen to that brother!
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Need to disagree. While the F4U's nasty stall has been neutered, the F6 is, IMO, one of the most stable planes in the set.
At low speed (under 150 mph), high AoA, the F6F-5 suffers from a roll axis instability that results in a snap roll to the left. Under the same circumstances the F4Us do not suffer this issue. I discovered this dueling the top F4U pilots in the game at the time. It made following their pitch-up maneuver very dicey. I figured a work-around that compensates for this behavior, and I can handle just about anyone in an F4U as a result. Nonetheless, the Corsair is more stable at the limit when using flaps. The Hellcat can defeat the F4U-1, -1A and -1D by bleeding off their E using the F6F's superior vertical performance (getting the nose higher than the F4U can). For example, Co-E (below 150 mph), the F6F can get better vertical displacement. However, you must recognize when you've reached the limit and ease off the stick ever-so-slightly. If you don't, the resulting snap roll will result in squandering any advantage built and even giving the F4U a shot. It's not that the F6F has a FM flaw, it's that the F4U lacks the basic instability historically attributed to the type.
In a constant horizontal turn on the deck (basic lufbery), the F4Us (except the -1C) turn smaller circles than the F6F can manage. However, this is offset by the F6F being able to get the nose higher and/or its slightly better turn rate. In the real world, a nose high, power off stall in an F4U would result in falling off on the left wing. Should the pilot firewall the throttle, the aircraft would roll inverted and not have enough aileron or rudder authority to prevent it. In the game, you can cob the power without fear.
My regards,
Widewing
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With the flight model and gamey landing gear tactics. F4Us especially the perk versions have become priority targets, even over dweebfires and other top tier rides. If I only get one kill in a furball I'll try make sure it's the F4U over anything else. And if I see a F4U against a friendly using landing gear and other gamey tricks to gain the advantage it will be one of the few instances where I will happily pick them off without a second thought.
And mtnman,
while you might only use landing gear for 1 in 500 fights. Flying against F4Us I come across landing gear being used by F4U sticks in over half the engagements I have, either to cause an overshoot or more often the case to prevent themselves from over shooting my Yak in rolls. And that includes some well known F4U sticks perk version or not.
<S>...-Gixer
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With the flight model and gamey landing gear tactics. F4Us especially the perk versions have become priority targets, even over dweebfires and other top tier rides. If I only get one kill in a furball I'll try make sure it's the F4U over anything else. And if I see a F4U against a friendly using landing gear and other gamey tricks to gain the advantage it will be one of the few instances where I will happily pick them off without a second thought.
Me likey shoot the corsair. Its definately a priority target for me.
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First to be targeted or not, the aircraft has issues.
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With the flight model and gamey landing gear tactics. F4Us especially the perk versions have become priority targets, even over dweebfires and other top tier rides. If I only get one kill in a furball I'll try make sure it's the F4U over anything else. And if I see a F4U against a friendly using landing gear and other gamey tricks to gain the advantage it will be one of the few instances where I will happily pick them off without a second thought.
And mtnman,
while you might only use landing gear for 1 in 500 fights. Flying against F4Us I come across landing gear being used by F4U sticks in over half the engagements I have, either to cause an overshoot or more often the case to prevent themselves from over shooting my Yak in rolls. And that includes some well known F4U sticks perk version or not.
<S>...-Gixer
How exactly is an F4U using its landing gear in a fight 'gamey' to you? :huh
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How exactly is an F4U using its landing gear in a fight 'gamey' to you? :huh
Unless it's using the gear to bounce off the ground, I wonder this as well?
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How exactly is an F4U using its landing gear in a fight 'gamey' to you? :huh
Because for the F4U with it's uber flaps and flight model performance makes the aircraft decelerate like Maverics F14 with an unrealistic ability to maintain zeke like performance at stupidly low speeds.
<S>...-Gixer
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What amazes me is the F4U's ability to pull the nose up starting at very low speeds and do a kind of back flip at 60 mph. This is in part a general strange thing about all FM in AH where the elevator is not loosing authority at stall speeds and so planes can pitch up into the stall at almost any speed. Coupled with the F4U flaps it allows the F4U to pitch up at speeds close to stall, either to shoot at someone zooming over it or switch direction from up to down without any displacement. Couple that with the F4u-4 gentle-torque high-power and you got a winner.
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The controversy surrounding the F4U's handling is one thing but think about it.. the gear used by some of our cartoon pilots is no more gamey than the flaps used on Spitfires. In fact, it wasn't too common for P-38 pilots to drop full flaps, though there are likely instances.
The gear on the F4U Corsair actually had a setting to drop just the main gear (tailwheel doors break off) during dive-bombing runs. Pilots actually used the gear initially as a speed brake but then the option for this speed brake was enabled in later F4U-1A's and subsequent models due to the high dive speeds encountered during bomb runs. So it actually would be possible to drop them to cause an overshoot.
The problem in this is that it would be suicidal for a Corsair pilot to get slow with flaps/gear in combat against the Japanese because of the obvious reasons. In our game, we have the advantage of stuff like combat trim, seemingly lower torque, a lot less engine management and the ability to up again and again. They didn't have the option.
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The controversy surrounding the F4U's handling is one thing but think about it.. the gear used by some of our cartoon pilots is no more gamey than the flaps used on Spitfires. In fact, it wasn't too common for P-38 pilots to drop full flaps, though there are likely instances.
The gear on the F4U Corsair actually had a setting to drop just the main gear (tailwheel doors break off) during dive-bombing runs. Pilots actually used the gear initially as a speed brake but then the option for this speed brake was enabled in later F4U-1A's and subsequent models due to the high dive speeds encountered during bomb runs. So it actually would be possible to drop them to cause an overshoot.
The problem in this is that it would be suicidal for a Corsair pilot to get slow with flaps/gear in combat against the Japanese because of the obvious reasons. In our game, we have the advantage of stuff like combat trim, seemingly lower torque, a lot less engine management and the ability to up again and again. They didn't have the option.
:rolleyes: You saying you would drop gear? cause no matter what that amounts to lame in my book seeing as the hog already has double the tricks of any other a/c.
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I've said this before, but there's only two circumstances I drop my gear in combat: Dive-bombing runs, and if I'm making any sort of extended dive onto a con to keep my approach speed manageable (primarily on initial dives into a fight if I have a particularly large starting altitude advantage). Typically I retract them again at 1500yds out so I can gain a few seconds of acceleration that can throw off the timing of his break (think about it: You spot a Corsair diving on your six, approaching steadily at about 100-150mph rate of closure. You're watching the counter click down ready to break, then all the sudden he's jumped up 250mph closure and he's on you before you can execute your evasive). However if I'm diving into a big cloud of red, it's gear up WEP all the way in.
The Corsair is too vulnerable once she's slow because it can take her so long to build her speed back up. The absolute WORST place to be in a big furball is in a Corsair wallowing around low and slow on the deck. You can't run away, and no matter what advantage flaps give you in a prolonged turning fight the Corsair's turn rate is just too poor and her vertical at low speeds is insufficient. When I'm fighting against another Corsair and I see those gear come out I know I've got him. He's either desperate or inexperienced, and is blowing all his E thinking it will give him a shot. Meanwhile I'm holding mine at about 250mph and extending up and away from him.
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Because for the F4U with it's uber flaps and flight model performance makes the aircraft decelerate like Maverics F14 with an unrealistic ability to maintain zeke like performance at stupidly low speeds.
<S>...-Gixer
Holy overstatement batman. Zeke like?? I think not.
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Holy overstatement batman. Zeke like?? I think not.
The F4U1 with full flaps has the same turn radius as an A6M5 without flaps. Consider that. Also, the flaps come out at much higher speeds, the airframe can take much more stress, and it can pull many more Gs, so it can get the flaps out faster, more effectively, and out-turn the zeke while it's still trying to slow down enough to pull 5Gs airframe stress.
Not as much an overstatement as you'd think. F4us in this game are porked to the extreme uber side of the spectrum. I've noticed this since the airflow code update.
Why did you think that suddenly, overnight, the F4U went from "as frequently seen as the P-47" to "as frequently seen as the spitfire"?
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Because for the F4U with it's uber flaps and flight model performance makes the aircraft decelerate like Maverics F14 with an unrealistic ability to maintain zeke like performance at stupidly low speeds.
<S>...-Gixer
I'm not disagreeing that the FM is a little buggy, but using what you have on your aircraft isn't gaming the game. That's like saying using the flaps, or the uber rudder is gamey...
<S>
donkey
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Why did you think that suddenly, overnight, the F4U went from "as frequently seen as the P-47" to "as frequently seen as the spitfire"?
I don't know where you're flying, but I don't see all that many F4Us--in fact, I rarely see more than two or three away from a carrier in the same furball except when I've got the rest of my squadron with me.
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I don't know where you're flying, but I don't see all that many F4Us--in fact, I rarely see more than two or three away from a carrier in the same furball except when I've got the rest of my squadron with me.
That's mostly true. I think a lot of people stay away from them because of the 6x.50cal armament (which I think is more than sufficient, but oh well).
On the other hand, I've seen the F4U surge in popularity from time to time, sometimes being more numerous than P-51s.
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Why did you think that suddenly, overnight, the F4U went from "as frequently seen as the P-47" to "as frequently seen as the spitfire"?
I'm sure you have the numbers to back that up.
Ohh and while we are at it. Why don't you look at turn rate not to mention virt performance at low speeds.
I'm not saying there isn't something wonky with the hogs slow speed performance. But claiming zeke at low speed :huh Thats over the top.
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I don't know where you're flying, but I don't see all that many F4Us--in fact, I rarely see more than two or three away from a carrier in the same furball except when I've got the rest of my squadron with me.
I actually tend to see more F4U's up from the carrier when doing a base attack, carrier defense tends to be Spitfire's and A6M's in my experience. The F6F is my favorite carrier plane and I've had times where I've noticed I'm literally the ONLY F6F in the sky while I'm surrounded by F4U's. I wish I could bring up the plane sheet on the website (doesn't seem to be working for me atm) before I say this so I don't get flamed, but I feel that the F4U series are probably one of the most popular attack planes off the carrier.
Quick question: I thought that combat trim was always set to one point (ie. the trimming that counters the torque of the engine at full throttle), is it actually dynamic based upon where your throttle settings are?
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I did the math once on flaps and turn radii once.
The average plane gets its turn radius reduced around 25% with full flaps.
Some oddities:
The P-51, with its maneuvering flaps, gets only a 19% reduction. Meanwhile, the FW-190, with its split-type flaps, NOT designed for combat maneuvers by any means, gets a 24% reductions
The P-38, with its large Fowler flaps (they move down AND backwards to actually increase wing area, very effective) gets a 26%. Not as much as advantage over plain maneuvering flaps as one would expect, to say nothing of the 190's split flaps.
Relevant to this topic, the Corsair gets 40%
Now, the Corsair was designed to land at ~75 mph on a carrier, so it SHOULD turn tighter than a P-47 or P-51 that was typically landed at 95 mph, but I agree the turn is probably a little too uber.
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Are we talking full flaps here, or just one notch? Because I could understand that at full flaps it gets 40% more lift for landing on a carrier, but at one or two notches that seems a tad much to me.
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Now, the Corsair was designed to land at ~75 mph on a carrier, so it SHOULD turn tighter than a P-47 or P-51 that was typically landed at 95 mph, but I agree the turn is probably a little too uber.
This topic has been addressed before. NACA windtunnel drag polar data for the F4U with flaps exists. Brooke used it awhile back to compare calculations against the AH FM and found that the AH F4U's full flap sustained turn performance is corroborated by the NACA data.
Tango, XO
412th FS Braunco Mustangs
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This topic has been addressed before. NACA windtunnel drag polar data for the F4U with flaps exists. Brooke used it awhile back to compare calculations against the AH FM and found that the AH F4U's full flap sustained turn performance is corroborated by the NACA data.
Tango, XO
412th FS Braunco Mustangs
I've been arguing that the turn radius is inconsequential anyway. Where the F4U modeling goes awry IMHO is in the virtual absence of torque induced roll, creating a measure of roll axis stability that is nothing short of ridiculous. Indeed, if the F4U was so endowed in the real world, accidents would have been all but nonexistent. Its stall behavior makes a Cessna 172 seem wild in comparison.
It may be that Combat Trim is the culprit here... I'll test that next.
My regards,
Widewing
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WW:
Yep, totally understand your position that you're not bringing up the F4U's turn performance but it's lateral stability. However the flaps-out turn performance issue always seems to creep up so I thought it appropriate to address it when folks bring it up.
On the issue of the F4U's low-speed lateral stability, I've followed the topic with some interest for awhile but haven't chosen to post anything on it for various reasons. Primarily I don't feel my thinking on the topic is organized enough yet :). I look forward to whatever else you and others turn up on the topic.
Tango, XO
412th FS Braunco Mustangs
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I don't have any of these issues and wouldn't know about low speed performance in the F4U's because I fly the thing like a rocket, and if I'm not mistaken that was the way the hog's were ment to be flown. :salute
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I don't have any of these issues and wouldn't know about low speed performance in the F4U's because I fly the thing like a rocket, and if I'm not mistaken that was the way the hog's were ment to be flown. :salute
they do like speed
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I dont think its combat trim. I noticed the plane doesnt seem to suffer from adverse yaw during rolls at slow speed. During a normal landing approach (for which corrections were made in r/l) the roll is not rapid but I see F4Us in the game use rapid rolls and whereas I believe they should lose substantial speed and the nose should yaw they dont.
Model aircraft adjust for this problem by using more up than down aileron movement to offset the increased drag upon the upward moving aileron. The question I have is the real corsair the same way? Perhaps to a degree but I dont believe so. If the upward moving aileron travels the same distance as the downward moving aileron then at slow speeds the corsairs should experience adverse yaw and more than they are in this game. If they move in differential amounts then at high speeds it will be more difficult for the plane to track true during heavy rolling and that would never be designed into a fighter. For that reason alone I believe there is a problem.
Its the same for the 190s also. They get into trouble and here comes a substantial roll followed by heavy pitch at near stall speed and they get away with it. I dont believe its realistic for heavily loaded airframes. Maybe for F3A aircraft but not fighters from WWII.
Several German fighter pilots during the war would use the rapid rolling motion of the 190 to decelerate and force an overshoot. The same deceleration is absent here or at least appears to be.
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sector!!! haha i clicked on a random article and it was urs...lol :rock
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sector!!! haha i clicked on a random article and it was urs...lol :rock
LOL! Way to contribute Fly! ;)
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I've been arguing that the turn radius is inconsequential anyway. Where the F4U modeling goes awry IMHO is in the virtual absence of torque induced roll, creating a measure of roll axis stability that is nothing short of ridiculous. Indeed, if the F4U was so endowed in the real world, accidents would have been all but nonexistent. Its stall behavior makes a Cessna 172 seem wild in comparison.
It may be that Combat Trim is the culprit here... I'll test that next.
My regards,
Widewing
I also felt (at least initially) that the Combat Trim may have been neutering the effects of torque, and mentioned it a few months back when this discussion came up last. I didn't do any real organized testing, but I found that even when using manual trim I couldn't get the F4U to display any bad behavior from torque effects, even at very slow speed. I don't think it's the CT at fault any more.
Personally, I suspect the tameness of the torque effects is whats leading to the "uber" flight model stigma. Especially since the data shown by Dtango and Brooke make the turn radius believable.
However, I do wonder how many planes have neutered torque effects. I doubt it's only a factor with the F4U. I don't really see any planes displaying the torque effects I would expect, but then again I don't have any first-hand experience with them in RL, or the mathematical ability to make a qualified statement. My feelings on the torque modeling are really no more than my opinion, which has been shown to be wrong at least once (many, many years ago, in a land far away...)
It would be nice to see some data, and a tweaked FM if necessary- I'm all in favor for as realistic of a FM as possible. I'm not in favor of adjusting the FM based on opinion, but in favor if data supports it...
MtnMan
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I don't really see any planes displaying the torque effects
MtnMan
Torque effect you say? 109f at very low speed try and roll right.
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Torque effect you say? 109f at very low speed try and roll right.
The same effect is present in almost all fighters, but it's not much an issue. Merely pull off power and it'll roll right. Like the F4U, the 109F is often flown at very low speeds with the flaps out. Therefore it is seen more often in these types.
The real issue as I see it is that most aircraft do not demonstrate the gyroscopic effect to the extent seen in the RL.
Speaking of odd FM things, has anyone ever done roll rate testing at high altitude? I have. Would you be shocked to see the 190D-9 rolling at over 240 degrees per second at 27k and 425 mph (it's around 140 degrees per second @ 225 mph and 500 feet)? How about the P-47 rolling at about 220 degree per second at the same altitude? Very strange, especially when one considers that control effectiveness should degrade with altitude and controls stiffen at higher speeds. I sent HTC an e-mail about this.
My regards,
Widewing
A high altitude
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WW wouldn't air density at that alt factor in a bit?
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Could go the other way with density Bronk... Most planes in extreme dives have to wait til the air is denser to get effective control back in their elevators to get the "bite" they need to pull up.
Maybe the thinner air has less pressure on the ailerons thus reduces roll rate?
(not sure, just thought about this as I read WW's post)
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WW wouldn't air density at that alt factor in a bit?
A mitigating factor is that not all aircraft see a big boost in sustained roll rate at high altitudes. The P-38L is unchanged from sea level. By the way, at 10,000 feet and 400 mph, the 190s roll faster (sustained) than the P-38L... That's absolutely incorrect. Nothing rolled faster at high speeds than the late P-38s with boosted ailerons... Nothing. NACA test data shows that the 190's roll rate degrades rapidly as speeds exceed 250 mph TAS. At 400 mph, its roll rate should be no greater than 70 degrees per second. Actual test data from the P-38L-1-LO shows that the P-38L rolls (sustained) at 95 degrees per second at 400 mph at 10k. Note the chart below... The roll rate degrades with altitude.
(http://home.att.net/~c.c.jordan/KelseyRoll.gif)
My regards,
Widewing
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Thanks to the both of you. I was asking because I was unsure. :aok
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Widewing, did you test those roll speeds off of IAS or ground speed? Reason I ask is, if your going faster in low density air, wouldn't you essentially have the same control as slower at lower altitudes?
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The chart he posted says adjusted true airspeed. Seeing as it's the same TAS but at different alts, and at higher alts it actually starts rolling WORSE, I don't think it works the way you describe.
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Widewing, did you test those roll speeds off of IAS or ground speed? Reason I ask is, if your going faster in low density air, wouldn't you essentially have the same control as slower at lower altitudes?
I can simplify this. I tested an F4U at 250 mph IAS at 27k, it rolled at 148 degrees per second. I then tested the same F4U at 250 mph IAS at 500 feet ASL, where it rolled at 91 degrees per second.
Why would this show such a difference of 51 degrees per second?
Some other fighters at 27k:
Bf 109K-4: 130 degrees (should be around 95 degrees)
P-51D: 145 degrees (should be around 95 degrees)
Spit Mk.IX: 143 degrees (should be around 105 degrees)
Fw 190A-8: 247 degrees (should be around 160 degrees)
All greatly exceed any data I've seen.
My regards,
Widewing
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Regarding roll rates….
Steady_roll_rate = roll_helix_angle * 2 * V / wing_span
Roll rate is absolutely a function of velocity. Higher velocity than higher the roll rate. What you see in AH is just that. I would expect a higher roll rate the faster you go. So why doesn't this match the NACA roll rates reported on the 190 and P-47? A few key things about that report. The figures are for a) IAS, b) 10k alt, c) fixed 50-lb stick force - this last item being very key in understanding the NACA chart.
The catch is that roll_helix_angle is also a function of other variables including air density and the amount of aileron deflection humanly/mechanically achievable.
Air density - As illustrated in Widewing's P-38 roll chart, at the same true airspeed because of the reduced density of the air the higher you go the roll rate would be lower because we're not able to generate the same amount of lift at a lower altitude. Thus if the aileron is deflected the same amount then assuming the exact same true airspeed but different altitudes the plane at a higher altitude rolls slower. This is what Widewing's P-38 chart shows.
Stick force - Generally the amount of aileron deflection that can be achieved in WW2 planes is constrained by how much an aileron can be deflected. Unboosted, this depends on how much muscle the pilot has. The faster you go, the greater the dynamic pressure. The greater the dynamic pressure the greater the hinge moments on control surfaces to move them. In other words the amount of force needed to displace an aileron increases with increasing airspeed. The NACA data referenced uses a constant stick force of 50-lbs. Here's the chart Widewing is referrring to:
(http://brauncomustangs.org/upload/rollrates.jpg)
That's why at a certain airspeed the roll rates degrade because at 50-lbs of stick force we're no longer able to deflect the aileron at it's maximum. I have no idea how Pyro and company model aileron deflection in AH and if they account for degrading aileron deflection decrease to simulate greater hinge moments. Seems like that would be difficult to do.
Another key constraining factor for aileron deflection is aerolastic bending at high dynamic pressures which distorts the control surfaces. That's a topic for another time :).
Tango, XO
412th FS Braunco Mustangs
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Widewing:
You need to do your tests at the same TAS not IAS. 250mph IAS at 27k is a lot faster than 250mph at 500 ft in TAS.
Tango, XO
412th FS Braunco Mustangs
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Widewing:
You need to do your tests at the same TAS not IAS. 250mph IAS at 27k is a lot faster than 250mph at 500 ft in TAS.
Tango, XO
412th FS Braunco Mustangs
Not in terms of airflow over the wing. 250 MPH IAS is the same no matter what altitude your at, but to acheive 250 MPH IAS at a higher altitude, you would have to have a faster TAS since the air is lighter up there.
WW, that is odd. Perhaps the control surface model in AH2 is based upon TAS? Would that make the roll rate calculate correctly if you pretended the TAS was actually the IAS?
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Not in terms of airflow over the wing. 250 MPH IAS is the same no matter what altitude your at, but to acheive 250 MPH IAS at a higher altitude, you would have to have a faster TAS since the air is lighter up there.
WW, that is odd. Perhaps the control surface model in AH2 is based upon TAS? Would that make the roll rate calculate correctly if you pretended the TAS was actually the IAS?
Hmm, I think you misunderstand me. TAS at 250mph IAS 27K is a lot faster than TAS at 250mph IAS ASL.
TAS is the actual airspeed of the aircraft with respect to the air through which it flies thus the airspeed that determines the aerodynamic forces on the airplane. TAS is the actual airflow speed over the aircraft. AH better model it's aerodynamic forces based on TAS not IAS otherwise it would be completely wrong.
Tango, XO
412th FS Braunco Mustangs
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Air density - As illustrated in Widewing's P-38 roll chart, at the same true airspeed because of the reduced density of the air the higher you go the roll rate would be lower because we're not able to generate the same amount of lift at a lower altitude.[/i] Thus if the aileron is deflected the same amount then assuming the exact same true airspeed but different altitudes the plane at a higher altitude rolls slower. This is what Widewing's P-38 chart shows.
I noticed something confusing I wrote that I can't edit now in a previous post. The bolded italics should read "because we're not able to generate the same amount of lift compared to a lower altitude".
Cheers!
Tango, XO
412th FS Braunco Mustangs
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Not necessarily, roll rates should be modeled on the IAS because of the air density change. Control surfaces have much less control power in lower density air than in the more dense low altitude air at the same TAS, same goes for lift off the wing. Because the air is lighter, you are technically flowing less of it over the wing at higher altitudes at the same TAS because there are fewer air molecules per unit^3 up at those alts. The pitot reflects this by showing a slower IAS. This is also why the aircraft will always stall at the same IAS, no matter what altitude your at.
IIRC, TAS is just ground speed corrected for wind. So 250 MPH TAS is the same no matter what altitude your at. 250 MPH IAS is much faster at higher alts than at sea level.
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Where to start. Let me use an example to demonstrate instead of trying to explain via theory. Here's a blow up of Widewing's P-38 roll rate chart.
(http://brauncomustangs.org/upload/example.jpg)
Points A and B are where the P-38's roll rate is the same at 10k as it is at 20k.
Point A IAS=169 mph, TAS=203 mph, roll_rate=60 dps
Point B IAS=153 mph, TAS=215 mph, roll_rate=60 dps
Points A and C are for the P-38 at the same IAS (169 mph IAS).
Point A IAS=169 mph, TAS=203 mph, roll_rate=60 dps
Point C IAS=169 mph, TAS=237 mph, roll_rate=70 dps
So here we have the P-38 at the same IAS (169mph) at either 10k or 20k. Notice that the P-38 actually rolls better at 20k vs. 10k when we compare the same IAS (169mph) at 10k and 20k.
If you want to know why that's the case, that's harder to explain easily (I can't think of a way at the moment). It has to do with the complexity embedded in the relationship I mentioned earlier:
steady_roll_rate = roll_helix_angle * 2 * V (in TAS) / wing_span
...specifically the complexity of the factors that affect roll_helix_angle.
Tango, XO
412th FS Braunco Mustangs
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Hmm, while it doesn't makes 100% sense to me, I'll take your word for it. I'll look into why this is on my own time so you don't have to type up a huge explanation just for me. :aok
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Ummm...okay, don't laugh at my ignorance for me asking this guys...
What would make Corsair models have bad torque problems compared to other WWII fighter aircraft? The horsepower/weight ratio isn't too extreme compared to alot of other planes. This is even the case with the F4U-4. So what made it so nasty at low airspeed/high power settings? Abrupt stall, lack of longitudinal stability?
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The power-weight ratio has absolutely nothing to do with the torque roll AFAIK.
I assume it's just the aircraft's geometric design.
If everyone flew P-38's we wouldn't need this conversation :D
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The power-weight ratio has absolutely nothing to do with the torque roll AFAIK.
I assume it's just the aircraft's geometric design.
If everyone flew P-38's we wouldn't need this conversation :D
Uh...forgive my ignorance, but I don't understand how the power of the engine in various aircraft can have NOTHING to do with torque roll at high power settings.
Wouldn't more power turning the prop make for more powerful opposite reaction?
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Points A and C are for the P-38 at the same IAS (169 mph IAS).
Point A IAS=169 mph, TAS=203 mph, roll_rate=60 dps
Point C IAS=169 mph, TAS=237 mph, roll_rate=70 dps
Correction to my last post. Point C roll_rate = 65 dps not 70. I can't divide right :).
Tango, XO
412th FS Braunco Mustangs
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BnZ,
I think the F6F and P-47 were more stable because of their taller fuselage reduced torque effect.
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The F4U1 with full flaps has the same turn radius as an A6M5 without flaps. Consider that.
Close, but not the same.
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I'm also wondering if torque truly "builds" as power is applied or whether torque effect is reduced as a throttle setting is maintained. I don't know, I'm just guessing here..
Crazy analogy- If I squeeze the trigger on my power drill, I feel torque try to twist the drill in my hand. The effect is greatest (from what I can tell) when I squeeze it suddenly and completely, but then as I continue to hold the trigger torque seems to lose some/most of it's effect. It actually feels like less torque, and more of a "gyroscopic" effect. And if I slowly squeeze the trigger I feel very little torque effect.
Anybody understand what I mean?
I would guess a similar effect happens with an airplane engine. Further complicated of course by the propeller, and again by the fact that the pitch/resistance of the propeller changes.
I would also expect that an airplane (let's just use the F4U, since it's the subject of the thread) flying at say 100 mph would react differently to a smooth application of full throttle, versus a sudden application of full throttle. The plane would be flying the same speed in both cases, same AoA, etc, but I would expect different torque "effects".
Can anyone explain/elaborate? I have zero expertise here, I'm hoping someone else can throw some facts out for me.
MtnMan
Another consideration- even in the slow turnfight scenario, we're still talking about an airplane that's moving at 100-120 mph, which is still pretty fast in reality. That's a lot of "mass in motion"- what kind of effect would torque really exhibit? I honestly don't have any idea, but I wonder if I expect more than would occur in reality? I'd guess the wings would have an effect of reducing felt torque as well.
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The thing about the F4U's wings that supposedly made it awful at low speeds, but great at high speeds, was the fact that they were "seagulled." That design of wing made it so the aircraft didn't compress in high speed dives, problem is, as I'm sure you can imagine, at low speeds when putting a lot demand on the wings, the air slides off the tips due to the angle of the wing. This causes the lifting effect of the wing to drop sharply and suddenly if pushed too far. So if you're pushing the aircraft to it's limits in a stall, than add ANY more throttle, your going to add more pressure to the outside wing, which eventually, will give due to lack of lift. On top of that, if you do tip-stall, it seems that the F4U recovers incredibly quickly and easily in-game. From what I've read, in real life stalls are VERY scary in an F4U.
The only reason you don't notice it on a power drill is because it's not at the limit of your hold. Assuming the drill is powerful enough, if you put it in an object that is trying to twist against you're hold to the extent of your strength, and you give it just a little more torque, your arm isn't going to be able to hold it at that position any more, so it'll twist.
Your technically getting the same overall amount of torque when applying slowly as quickly, but when applying slowly, your muscles have time to react. In a sudden tip-stall scenario, it'd be more like just flooring the drill because it's so sudden most of the time.
However, all this info is based upon what I have read, so please feel free to correct me if I'm wrong.
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The thing about the F4U's wings that supposedly made it awful at low speeds, but great at high speeds, was the fact that they were "seagulled." That design of wing made it so the aircraft didn't compress in high speed dives, problem is, as I'm sure you can imagine, at low speeds when putting a lot demand on the wings, the air slides off the tips due to the angle of the wing. This causes the lifting effect of the wing to drop sharply and suddenly if pushed too far.
Not true.
The wing design was to reduce drag and allow a shorter gear leg while still getting adequate prop clearance. The gull wing reduced drag by having the wing root at a right angle to the fuselage. All wings "lose" some lift near the tip due to the tip vortice. The out wing panels of a Corsair don't have a great deal more dihedral than many other designs, it's just exaggerated by the gull wing shape.
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Not true.
The wing design was to reduce drag and allow a shorter gear leg while still getting adequate prop clearance. The gull wing reduced drag by having the wing root at a right angle to the fuselage. All wings "lose" some lift near the tip due to the tip vortice. The out wing panels of a Corsair don't have a great deal more dihedral than many other designs, it's just exaggerated by the gull wing shape.
Was actually just looking over the Wiki on it when I got the notification of your post and saw that little bit of information. Guess you can't believe everything you hear! Wonder if the compression bit has any merit though? Seems plausible.
I did know that all planes had that tip vortice effect, but from what I understood before, it was worse on the F4U. Now I read the Wiki and it tells me that the seagull design affected "elevator authority," and was fairly bad before that spoiler, that was mentioned earlier, was installed. Perhaps I misunderstood the fellow I was speaking with on the subject.
Sorry 'bout that, good to get things straight though! :aok
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MtnMan,
That was the major cause of stall instability in the F4U: Inexperienced pilots would accelerate hard on the throttle when they felt the ship losing control. The sudden application of power would only exacerbate the problem. This same issue was not unique to the F4U, however she WAS the first carrier bird to have so much engine power that this became an issue, as opposed to the much less powerful Wright engine on the F4F.
Sector,
You also have to consider that the F4U gets a subtle increase in wing area due to the wing configuration. The inverted gull design actually gives the Hog a slightly greater wingspan than a comparable aircraft, not tremendous, but still significant.
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Read this gents... NACA Report No. 829
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930091906_1993091906.pdf (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930091906_1993091906.pdf)
My regards,
Widewing
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With regards to the F4U's lift coefficient and great turning capabilities, I just realized that not even in ONE thread (that I was able to search up) has someone been able to mention the mysterious 'panels' under the wing... just forward of the leading edge of the flaps, under the wing.
(http://farm1.static.flickr.com/188/379794001_884645cdd2.jpg?v=0)
(http://fineartamerica.com/images-medium/1-chance-vought-fg-1d-corsair-3111-sidney-chambers.jpg)
Sorry, I can't find better images.
What happens is, as the flaps fold downward, these 'panels' actually collapse into the wing. The effect is that a lot of air goes through and is compressed to be pushed out the tiny space in between the wing and the flap itself. This speeds up the air generating much more lift than a conventional slotted flap.
And THAT's why the F4U generates so much more lift than a P-47.
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bzzzt, nope.
P-47 has the same slot/gap.
IMO it's too thin to really get air flowing from under to over. I'm not an expert like some but if you look at any wing with slotted flaps you find much more space for the air to flow.
remember, it has to flow freely. Heck, the 109E had more of an air pass-through than the F4u, just looking at reference photos.
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Hm. I thikn I just found some pics of P-47 flaps. Theydon't show enough of the wing to see, but from what I see, there are no such panels. Just saying, I can't see them yet. If you have some photos I'd gladly like to take a look :) At any rate, WW's posted test seems to provide evidence of the F4U's flaps being more efficient anyway.
(http://www.aircraftresourcecenter.com/AWA1/001-100/walk057_P-47M/images/P-47M%20flap.jpg)
However, it's not really due to opinion if you think it's too small or whatever. If it works it works. If it doesn', it doesn't.
What makes the F4U flaps effective is the speed of the air over the flap. The air is exiting a space much smaller than the space through which it entered. Whether the slot is big or not is likely out of question. The P-47M's flap as shown above, has an exit space similar to the entrance space.
EDIT: added pics, fixed some points.
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I'm not a pilot or an expert, but I have watched and read a little about WWII air combat and when it comes to American Iron you "rarely" hear anything about a pilot deploying flaps during air combat. The excepted dogfighting maneuver was to come in fast and hit and run, gain altitude and come back for another pass.....referring to dogfighting the Japanese planes where the F4U's & P-38's where mainly flown. Now in the European theater I don't think turn fighting was much of an issue because the German fighter's by design were not considered turn fighters and that is why they had such a hard time with Spits and hurricanes. Unfortunately, in the AH2 theater you have planes fighting against each other that in real life were never meant to be matched up.
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the reason the wings were designed the way the were, was to allow clearance for the prop,simple as that.
and by making the wings "gull" thats were the low speed instabilaty cames from.
i could be wrong, :noid
ether way, the only F4 ive had issues with is AKDOGGs, he knows that plane very well.
they certainly dont fly like a zero.
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Cajun: I was actually watching something the other day where a P-47 deployed his flaps against a 109, I believe a Pony did it later in the episode as well. I'm sure it really depends on the scenario more than anything. :salute
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Hm. I thikn I just found some pics of P-47 flaps. Theydon't show enough of the wing to see, but from what I see, there are no such panels.
No, but you notice how the entire flap pushes down and away, and allows air to flow between it and the wing? This as compared to a solid-hinge flap that simply rotates from where it is without dropping.
Same end result.
Let's face it, the F4U is not modeled accurately in this game. Literally overnight it went from average, decent, if you know how to fly it, to "able to out turn anything in the game and stay with zeros in turns"
I'm sorry. Maybe the early version wasn't right, and needed fixing, but this is giong too far the opposite way. Reality lies between the two I think. More towards the previous generation of flap code than the current one, IMO.
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No, but you notice how the entire flap pushes down and away, and allows air to flow between it and the wing? This as compared to a solid-hinge flap that simply rotates from where it is without dropping.
Same end result.
Let's face it, the F4U is not modeled accurately in this game. Literally overnight it went from average, decent, if you know how to fly it, to "able to out turn anything in the game and stay with zeros in turns"
I'm sorry. Maybe the early version wasn't right, and needed fixing, but this is giong too far the opposite way. Reality lies between the two I think. More towards the previous generation of flap code than the current one, IMO.
The F4U was just about as capable before the rework of the drag model. Little changed with it since AH2 came online. The thing was, very few bothered to use flaps prior to the discovery of what you could actually do with the flaps. When the Spit16 first came out I demonstrated how the F4U could give it fits. That was when, three years ago?
I think the research shows that the F4U's flaps are not very far from reality. If you argue that the F4U is too stable near stall speed, you have a case there. A good one.
My regards,
Widewing
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Well, Krusty, the Corsair's flaps aren't solid hinged either. Otherwise, you wouldn't have a slotted flap.
If anything, Widewing's stability issue is more correct. DTango disproved any doubt I had about the Corsair's turning ability and now, we know, that the Corsair is too stable. I believe it would fly more accurately if it had the torque reactions of a Spitfire XIV or a 109F.. I believe you stated that in a prior thread.