Flap torque tube slot seal

DETAILED DESCRIPTION The present invention provides an improved closure apparatus for blocking airflow through a curved slot formed in the side wall of an aircraft fuselage adjacent to an inboard wing trailing edge flap.
The curved slot provides clearance for displacement movement of a flap torque tube when the flap is moved between a retracted forward position and a fully extended rearward position.
In the disclosed airplane, the inboard carriage for the wing inboard trailing edge flap is located inside a body/wing fairing which is located adjacent to a main landing gear wheel well.
The inboard trailing edge flap is attached to the carriage by a torque tube which penetrates the body/wing fairing and thus requires a cutout or slot in the body/wing fairing through which the torque tube can travel as the flap is extended or retracted.
The slot is covered by the flap end cross-section area when the flap is in the raised and stowed position; however, when the flap is in the fully extended and lowered position for the landing mode, the slot opening is exposed; and airflow from the main landing gear wheel well passes through the slot opening to the lower pressure region on the upper surface of the extended flap.
This spanwise airflow causes a separation of the boundary layer airflow at the inboard or root end of the flap.
The effect of this separation of the boundary layer airflow from the upper surface of the flap during the landing mode, or during the flare out just prior to touch down, causes a decrease in the coefficient-of-lift C.
sub.
L and a loss of lift.
The normal reaction of the pilot to this sudden increase in rate-of-descent is to pull back on the yoke, thereby increasing the nose-up attitude of the airplane and causing the tail section of the fuselage to strike the runway.
Also, the effect of the separation of the boundary layer airflow from the upper surface at the inboard end of the flap produces a turbulent wake that trails aft and strikes the horizontal stabilizer, producing a vibration which can be felt by the pilot in the cockpit