Sec. 25.701 - Flap and slat interconnection.
(a) Unless the airplane has safe flight
characteristics with the flaps or slats retracted on one side and extended
on the other, the motion of flaps or slats on opposite sides of the plane
of symmetry must be synchronized by a mechanical interconnection or
approved equivalent means.
(b) If a wing flap or slat
interconnection or equivalent means is used, it must be designed to
account for the applicable unsymmetrical loads, including those resulting
from flight with the engines on one side of the plane of symmetry
inoperative and the remaining engines at takeoff power.
(c) For airplanes with flaps or slats
that are not subjected to slipstream conditions, the structure must be
designed for the loads imposed when the wing flaps or slats on one side
are carrying the most severe load occurring in the prescribed symmetrical
conditions and those on the other side are carrying not more than 80
percent of that load.
(d) The interconnection must be designed
for the loads resulting when interconnected flap or slat surfaces on one
side of the plane of symmetry are jammed and immovable while the surfaces
on the other side are free to move and the full power of the surface
actuating system is applied.
[Amdt. 25-72, 55 FR 29777, July 20, 1990]