Apco’s HIT Valves are designed to improve the wing’s stability and performance at high speeds. The valves located on the leading edge will open automatically when the internal pressure of the wing drops, improving the stability of the wing.
A few valves along the span of the leading edge are sufficient to pressurise the entire wing during accelerated flight or loss of internal pressure.
HIT valves – another exclusive innovation from APCO often copied, never matched.

UNACCELERATED FLIGHT
During unaccelerated flight the leading edge intakes are designed to face the profile’s stagnation point, ensuring maximal internal wing pressure.

Fig. 1 illustrates stagnation point below the hit valve and the valve is closed

ACCELERATED FLIGHT
During accelerated flight, the stagnation point moves higher up, above the leading edge intakes, thus reducing the internal pressure of the wing.

The addition of HIT valves which in accelerated flight face the stagnation points allows to maintain the internal pressure of the wing at low angle of attack as well. Greater stability at any speed is guaranteed by HIT valve. (Fig. 2)

HIT Valves