In the event of complete hydraulic power failure, the
others use a ram-air-driven turbine for operating the
pilot may pull a handle in the cockpit to disconnect the
emergency system pump.
latch mechanisms from the cylinder and load-feel
Lateral Control Systems
bungee. This places the aileron system in a manual
mode of operation. In manual operation, the cable
Lateral control systems control roll about the
sector actuates the power crank.
longitudinal axis of the aircraft. On many aircraft the
This lateral control system incorporates a load-feel
aileron is the primary source of lateral control. On other
bungee, which serves a dual purpose. First, it provides
aircraft flaperons and spoilers are used to control roll.
an artificial feeling and centering device for the aileron
AILERONS.--Some aircraft are equipped with a
system. Also, it is an interconnection between the
power mechanism that provides hydraulic power to
aileron system and the aileron trim system. When the
operate the ailerons. When the control stick is moved,
aileron trim actuator is energized, the bungee moves in
the control cables move the power mechanism sector.
a corresponding direction and actuates the power
Through linkage, the sector actuates the control valves,
mechanism. The power mechanism repositions the
which, in turn, direct hydraulic fluid to the power
aileron control system to a new neutral position.
cylinder. The cylinder-actuating shaft, which is
FLAPERON.--As aircraft speeds increased, other
connected to the power crank through a latch
lateral control systems came into use. Some aircraft use
mechanism, operates the power crank. The crank
a flaperon system. The flaperon, shown in figure 2-5, is
moves the push-pull tubes, which actuate the ailerons.
10.
Flaperon control linkage
6. Wing-fold interlock mechanism
1.
Wing-fold flaperon interlock switch
11.
Flaperon actuator (left wing)
7. Filter
2.
Flaperon control linkage
12.
Crossover cables
8. Flaperon pop-up mechanism and
3.
Right wing flaperons
13.
Pushrods
cylinder
4.
Flaperon actuator (right wing)
14.
Throttle quadrant
9. Left wing flaperons
5.
Flaperon pop-up valve
Figure 2-5.--Flaperon control system.
2-6
