Best "maneuvering" flaps: Fowler or Fairey Youngman type?

[BarnOwlLover]

Both are noted for enhancing lift and maneuverability of aircraft fitted with them. I know that the Ki-43's flaps were basically similar to Fowler flaps, while the Youngman flaps were used on the Fairey Firefly. But which system was better, be it from a mechanical standpoint of performance. I do believe that it should be noted that only a few production aircraft used Fairey Youngman flaps (Firefly, Barracuda, Spearfish prototypes, Westland Wyvern), while Fowler flaps have been commonly used since World War II (and even a short time beforehand).

 

[ThomasP]

From what I have read, the Fairey-Youngman would be superior when used for take offs due to lower drag per unit of lift, and they could act as flaperons (augmenting the standard ailerons) at lower (WWII) speeds, thus increasing roll rates at lower speeds and control during take-offs and landings. They could also be setup for use as dive brakes. So I think they get the nod in terms of versatility and low speed handling.

But, the Fowler were simpler and lighter in weight per unit lift generated, and the installation incurred less drag when stowed vs the Fairey-Youngman type - at least in the WWII applications.

In effect the Fairey-Youngman flaps acted as Junkers/multi-airfoil flaps in one mode, and as slotted Fowler flaps in another mode. I think that in actual use both types had about the same maximum practical lift coefficients.

I do not know what the trade-offs would be for modern versions, though in so far as there are no examples that I am aware of where the Fairey-Youngman flaps are used in larger aircraft, I have to assume that the Fowler type is superior in practical applications. I believe most of the large commercial jet airliners use one form or another of the Fowler flap. The only aircraft that I am aware of that still use Fairey-Youngman or Junkers flaps are a few small civil aircraft and some ultralights.

 

[BarnOwlLover]

I do wonder what would be better for a conventional single seat single engine World War II fighter. Or would for most applications split flaps or slotted flaps suffice? Most British designs used split flaps while most US designs (P-51, P-47, F6F, F4U, P-61) and the DH Mosquito used slotted flaps. I'm looking at low speed maneuvering and take off/landing characteristics.

 

[Simon Thomas]

The Gouge flap is a rather clever design, that has never got the respect it deserved.
It was successful on the Empire and Sunderland, which obviously had a great need for additional lift and low drag for takeoff .
It may not be useful at low speed maneuvering due to the time taken to extend and retract.

 

[wuzak]

I do wonder what would be better for a conventional single seat single engine World War II fighter. Or would for most applications split flaps or slotted flaps suffice?

The Fairey-Youngman and Fowler flaps require actuation mechanisms that protrude from the wing.

May not be the best for a single seat S/E fighter.

 

[ThomasP]

IIRC the Ki-43 and Ki-44 'butterfly' flaps were a version of the Fowler flap, and the J2M was fitted with (single-slotted?) Fowler flaps. The A7M was also designed to use Fowler flaps. I do not know enough about what the trade-offs were to comment otherwise.