Figure 16-9.--Aileron power mechanism.
autopilot actuator and a flaperon power actuator in
addition, the folding operation cannot start unless the
each wing).
flaperons are flush with the wings.
Control stick movement, left or right, raises the
A wing-fold interlock prevents flaperon pop-up
respective two flaperons, while the opposite two
after the wings are folded. A fail-safe spring returns the
remain flush with the wing. Full throw of the control
flaperons to the flush position in case the combined
stick by the pilot causes the inboard flaperon to rise 49
hydraulic system or electrical system should fail.
l/2 degrees and the outboard flaperon to rise 53
The eddy current damper links mechanically to a
degrees. In flight, the flaperon can also be positioned
bell crank in the flaperon control linkage. See figure
by the AFCS. Control stick movements are transferred
16-11. It dampens any rapid left or right control stick
through the pushrod and bell crank system to the
movement by producing an opposing force
flaperon autopilot actuator. Mechanical outputs from
proportional to the speed at which the stick is moved.
this actuator are conveyed to a gearing mechanism, at
The damper contains permanent magnets, a rotating
which point linkage to the left and right wing flaperon
copper disc, a gear train, and a clutch assembly.
power actuators separates. The gearing mechanism
Control stick motion rotates the clutch and gear train,
transmits movement to the left or right flaperon, while
which, in turn, rotates the copper disc. The copper disc
the opposite flaperon is maintained flush with the
is sandwiched in the air gap between the six permanent
wing. When the flaperon pop-up cylinder is actuated,
magnets and a flux plate. As the copper disc revolves,
the gearing mechanism transmits pop-up motion to
the magnetic field between the magnets and the flux
each wing flaperon power actuator.
plate is disturbed, causing an opposing force (eddy
The semiautomatic flaperon pop-up device aids in
currents) that tries to stop the disc. The opposing force
reducing ground roll during landing. The pop-up
is proportional to the speed of the rotating disc and to
system is activated by the pilot placing the flaperon
the speed of stick movement. The clutch will slip at a
pop-up switch in the ARM position. All flaperons
force of 275 to 325 inch-pounds to prevent control
(four) will then automatically pop up approximately 41
stick binding if the damper jams.
degrees when the aircraft weight is on the landing gear
Figure 16-12 illustrates a representative flaperon
and the throttles are retarded.
control system. The flaperon autopilot actuator is
A mechanical interlock device prevents damage to
powered by the flight hydraulic system and transmits
the flaperons during folding of the wings. When the
mechanical movement to the flaperon power actuators.
wings are folding, the flaperons cannot be extended. In
The flaperon power actuators are tandem type and
16-10
