GRUMMAN AMERICAN
FOR TRAINING USE ONLY – SECTION 7
MODEL GA‐7/COUGAR
AIRPLANE & SYSTEMS DESCRIPTIONS
7‐4
Issued: April 10, 1978
FLIGHT CONTROLS
The flight controls consist of the ailerons, elevators, rudders, and their respective trim systems. The control
surfaces are constructed of spars, ribs, and bonded skins. The control surfaces are ball bearing mounted and
operated through push‐pull rods and conventional cable systems, terminating in bellcranks.
AILERON CONTROL SYSTEM (Figure 7‐1)
The ailerons are driven through a chain and cable drive system. A series of cables and pulleys are routed from the
control column through the center console and out into the wing to a bellcrank. The aileron is connected to the
bellcrank with a pushrod, using standard rod ends. As a result of the gear ratio provided by the control column
and bellcrank arrangement and the static balance on the aileron, the GA‐7/Cougar is provided with an extremely
smooth, light, and readily responsive aileron control system.
AILERON TRIM SYSTEM
The aileron trim control system provides a means to trim the airplane about the roll axis and compensate for
variations in attitude caused by passenger and cargo loading. With the aileron trim control knob positioned so that
the pointer is in the neutral (vertical) position, the airplane should be slightly heavy on the left wing when flying
solo.
The aileron trim control knob is connected by a system of levers and pushrods to a bungee at the top of the control
column (Figure 7‐1). With the control knob in the neutral position, spring action in the bungee will return the
ailerons to the neutral position each time pressure is released at the control wheel. As the aileron trim control
knob is rotated from the neutral position, a corresponding amount of pre‐loading is introduced into the bungee,
resulting in each aileron being returned to a point slightly away from the neutral position.
ELEVATOR CONTROL SYSTEM (Figure 7‐2)
Each elevator is basically a bonded structure composed of ribs, spars, skins, torque tube, and tip cap. The trailing
edge of the right elevator contains a hinged trim tab. The elevator is operated by moving the control column
forward or aft. As the control column is moved fore and aft, the displacement is transmitted by a pushrod to the
elevator control bellcrank located forward of the rudder pedals. The elevator control bellcrank in turn operates
the up and down elevator cables which transmit the control wheel displacement to the aft elevator bellcrank
located in the aft fuselage. Two pushrods, connected to the aft elevator bellcrank, transmit the motion to a
corresponding horn attached to each elevator torque tube. Counter balance for the elevator control system is
provided by a bob weight and down spring located in the left side of the nose section, beneath the nose baggage
compartment floor.
