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View Full Version : OK. What are "butterfly flaps"?



Doug_Thompson
05-11-2005, 09:34 PM
I keep reading about how Nakajima used "butterfly flaps" to get more maneuverability out of its fighters, from the Ki-27 to the Ki-84.

But I've never seen what "butterfly flaps" look like, how or whether they are different from regular flaps if they are different. What's the story?

Doug_Thompson
05-11-2005, 09:34 PM
I keep reading about how Nakajima used "butterfly flaps" to get more maneuverability out of its fighters, from the Ki-27 to the Ki-84.

But I've never seen what "butterfly flaps" look like, how or whether they are different from regular flaps if they are different. What's the story?

Doug_Thompson
05-11-2005, 10:04 PM
May have answered my own question:

http://modelingmadness.com/scotts/axis/j/ki43ij.jpg

Apparently, they are flaps designed to increase wing area without increasing drag. Regular flap increase wing area but also create drag to slow the plane down.

They're very visable in Pacific fighters, on the underside of the Ki-43. On the Ki-84, they look more like regular flaps, but they don't seem to decline as much as regular combat flaps.

stansdds
05-12-2005, 03:55 AM
Looks akin to the Fowler flap, except Fowler flaps also turn down as they extend rearward.

3.JG51_BigBear
05-12-2005, 07:40 AM
Because of the way that butterfly and fowler flaps extend backwards from the wing they could be opened at higher speeds than standard flaps. It was a huge advantage in real life but since combat flaps can be opened on any plane at any speed in game they're not as cool as they should be.

VW-IceFire
05-12-2005, 10:37 AM
P-38 employes "fowler flaps" as well...can be a big advantage in some situations.

Doug_Thompson
05-12-2005, 10:54 AM
Apparently, butterfly flaps went as straight back as possible, increasing wing area. Fowler flaps went back and down, using much more advanced aerodynamics to a greater overall effect. At least that's what targetware says on its instructions for computer modelling the animation: See here (http://www.targetware.net/devguide/3d/2_animating.html)

tjgoetz
05-12-2005, 01:49 PM
A number of Japanese planes used butterfly flaps, including the Tojo, Oscar, and Frank. As I understand it, they could be extended back to increase the wing area, or back and lowered to increase the manuverability. Since Japanese design philosophy empahsized high manuverability, it was a fairly natural innovation. And since Japanese tactical doctrine emphasized dogfighting at slower speeds, anything that increased that ability would be used on the planes.

3.JG51_BigBear
05-12-2005, 02:59 PM
I know that, on the 43 at least, there was a control for the combat flaps right on the stick so that the flaps could be easily dropped in a turning fight where a pilot couldn't afford to take his eyes of the enemy.