Figure 2-4 Control Stick

CHAPTER TWO

T-6A CONTACT

202.

SECONDARY FLIGHT CONTROLS - TRIM DEVICES

The secondary flight controls include electrically actuated pitch/roll/yaw systems and a rudder

trim aid device (TAD). The secondary flight controls are used for trimming and balancing the

aircraft in flight and to reduce the force required to actuate the primary flight control surfaces.

Trimming the aircraft is an essential skill for you to master and its importance is often

overlooked by fledging aviators. When an aircraft's flight conditions (attitude, power, airspeed,

loading and configuration) are changed, the control pressures required to maintain the desired

conditions are affected by the resulting changes in aerodynamic forces. The T-6A is equipped

with systems that allow you to trim the aircraft for balanced flight in all axes.

Trim System and Switches

The elevator and aileron trim are utilized by a thumb-actuated switch (Figure 2-4) at the top of

the control stick (fore/aft for elevator trim and laterally for aileron trim). The rudder trim switch

is located on the forward side of the power control lever (PCL). To trim, deflect the trim switch

in the opposite direction as the applied flight control force until that force is relieved. When

perfectly "trimmed," you can release flight control pressures (momentarily) and the aircraft will

remain in its current balanced state, then actuated, the Trim Interrupt button on the control stick

will remove electrical power from the trim devices and is used during certain trim malfunctions.

The general sequence for trimming the aircraft is: Rudder, Elevator, then Aileron. The rudder

trim is usually first because a correction for yaw precipitates a change in the trim setting for pitch

and roll. Consequently, not trimming the rudder first will generally cause you to go back and re-

trim the elevator and aileron after trimming the rudder.

Elevator/

Aileron Trim

Trim

Interrupt

NACWS

Proximity

Range

Select

Nose Wheel

Steering

Figure 2-4 Control Stick

2-4

THE FLIGHT CONTROLS