Author Topic: F4u flaps (Read 7315 times)

john9001 · « **Reply #15 on:** November 14, 2006, 08:20:08 AM »

sounds like somebody got pawned by a F4U in a turn fight,

Saxman · « **Reply #16 on:** November 14, 2006, 08:25:20 AM »

The difference in stall speed in the F4U at power off clean and full flaps is 13%, which is STILL nearly DOUBLE the difference as in the P-51. And the Hog is 3000lbs HEAVIER.

There's SOMETHING about the REAL F4U--if the pilot's manual is to be believed, which why wouldn't it be? That's written for the safety of the pilot so if anything would be CONSERVATIVE in its estimates--that makes her flaps much more efficient than in other aircraft.

Benny Moore · « **Reply #17 on:** November 14, 2006, 09:15:58 AM »

They may be more effective, but not more efficient. Lowering the stall speed more doesn't mean they're more efficient. The drag is probably proportional, since the F-4U had conventional flaps. The P-38's Fowler flaps were more efficient; they greatly lowered the stall speed without greatly increasing drag. Even though the F-4U has a much lower stall speed with flaps, that doesn't mean its turn will be better. It will be tighter, but a lot slower because it doesn't have Fowlers. Moreover, the F-4U without flaps in game doesn't have a wide turn at all.

F4UDOA, how do you know that Dean's graph is wrong? And can you post corrections? Aside from that graph, I've seen another NACA graph comparing the F-4U, a few American airplanes, and the Spitfire. Once more the F-4U was on the outside. Unless you can convince me otherwise, I still believe that the F-4U has far too good of turning ability in the simulator.

Bronk · « **Reply #18 on:** November 14, 2006, 10:42:25 AM »

Where is Widewing when you need him .

Bronk

F4UDOA · « **Reply #19 on:** November 14, 2006, 12:59:52 PM »

Benny Moore,

Sure no problem, my favorite subject. In fact I can show you exactly where Dean's number came from.

However I am working at the moment so I will post tonight in greater detail.

FYI, I would tend to agree that the F4U flaps are not of a "special design" and did produce proportionate drag to lift. However the drag at that speed would not have very much effect IMHO (engineers jump in). Case and point you add more flap not less to take off quickly. Yes your acceleration is less but the lift generated overcomes the drag. You don't have to turn as fast when you are turning so tightly which is what happens in AH.

Also despite weighing 12,000LBS fully loaded the wingloading of the F4U is low with good power loading for an American A/C and that is without flaps.

Ball · « **Reply #20 on:** November 14, 2006, 01:20:40 PM »

Quote

Originally posted by Trikky
I'm no expert either which may explain why I find the F4U's handling the least convincing out of the entire planeset. I find it odd that the fabled Ensign Eliminator with all the torque, and yes I know they added the strip to compensate, can virtually hover onto the carrier and land on its rudder.

What intrigues me most is how they dump all flaps and gear and loop at about 40 mph.

yet the Spit 14, Typhoon, Mosquito and Tempest all suffer horrendously with torque.

auto takeoff cannot even keep the wings level on the hawkers on climbout, and the mosquito snakes around with its tail wagging like a stoned puppy.

Bodhi · « **Reply #21 on:** November 14, 2006, 05:47:15 PM »

Quote

Originally posted by Krusty
The gull wing was to shorten the landing gear. It wouldn't really change the lift of a wing much (it was an old design, even Junkers took it from somewhere else to use on their Stuka). It has been around since biplane days.

The gull wing was indeed added to the Corsair to make the landing gear shorter.

Unintended consequences though of the shortened gear went into decreased drag owing to the perpendicular attach point of the wing root. Increased lift owing to the larger wing area resulting from the extra wing required to form the gull. Lastly, the form and area of the flaps differs greatly from most other American fighters, and I believe this also plays a role in their increased maneuvering effectiveness.

Saxman · « **Reply #22 on:** November 14, 2006, 09:09:15 PM »

Best explanation I can think of. Would be nice if someone could dig up tests that confirm that.

Bodhi · « **Reply #23 on:** November 14, 2006, 09:12:37 PM »

Quote

Originally posted by Saxman
Best explanation I can think of. Would be nice if someone could dig up tests that confirm that.

The sad thing is, I spent most of last month working on a new set of flaps for a -4 (no difference between the dashes btw) and I can not remember the data to go along with their form... sad huh!

Will be talking to several accomplished F4u pilots tomorrow, and will post their thoughts tomorrow night, or next day... TX day trips are hard on me... usually to fugged up to talk let alone type by the time the cab drops me off at home!

Saxman · « **Reply #24 on:** November 14, 2006, 09:56:26 PM »

Cool, cool. Although I'll be expecting the whiners to gun their thoughts down as prejudice.

Stang · « **Reply #25 on:** November 14, 2006, 10:12:28 PM »

All I know is that I outturned, in a flat turn of 3 full circles, a Spit IX while flying an F4u-1. The flaps on it are unreal. And it wasn't some nood I was fighting, it was Bronk. I'm sure he was surprised by it as well.

I have seen what Widewing has posted about the F4u-4 outturning the SpitXVI, but I sure didn't expect a U-1 to outurn a better turning spit easily in the Mk IX.

Bronk · « **Reply #26 on:** November 14, 2006, 10:17:48 PM »

Quote

Originally posted by Stang
All I know is that I outturned, in a flat turn of 3 full circles, a Spit IX while flying an F4u-1. The flaps on it are unreal. And it wasn't some nood I was fighting, it was Bronk. I'm sure he was surprised by it as well.

I have seen what Widewing has posted about the F4u-4 outturning the SpitXVI, but I sure didn't expect a U-1 to outurn a better turning spit easily in the Mk IX.

Would a had ya to but i forgot to swap back to cannon after dropping my tank.

So all i pingged you with were GD 303

But yup after i blew my oppertunity he just floated away from me in a tight right hand turn.
Nice slow speed control Stang .

Bronk

bozon · « **Reply #27 on:** November 15, 2006, 12:08:29 AM »

Quote

Originally posted by F4UDOA
FYI, I would tend to agree that the F4U flaps are not of a "special design" and did produce proportionate drag to lift. However the drag at that speed would not have very much effect IMHO (engineers jump in). Case and point you add more flap not less to take off quickly. Yes your acceleration is less but the lift generated overcomes the drag. You don't have to turn as fast when you are turning so tightly which is what happens in AH.

Flaps, do not "improve" turning where you can sustain a turn without flaps. What they do is extend some of the flight envelope to areas that you can't reach without them due to angle of attack limitation. The price is very much reduced efficiency, meaning for every little extra lift you get, you pay with a much larger amount of drag.

In other words, flaps allow one to convert extra engine power into lift without increasing speed, and where you have passed the normal critical AoA. Yet even this contribution is limited since it has its own new critical AoA, even if you do have the excess power.

I do not buy the "its a gull wing so it works differently" argument. While the gull wing has some interesting properties, it was not such a stellar design. The simple (circumstantial) proof of that is that it hasn't been used since the need of getting the gears low enough to clear the prop has been removed.

Stoney74 · « **Reply #28 on:** November 15, 2006, 01:09:58 AM »

Why don't we just wait until the remodeled versions come out before we get too involved in this discussion? Could be the F4U's benefit from the old flight model--something the updated planes don't benefit from?

Krusty · « **Reply #29 on:** November 15, 2006, 01:41:19 AM »

I don't know about that. Since the re-coding of the airflow coad, I think things have settled down a bit. We'll see minor changes, I'm sure, but flaps haven't changed in a while.