Trim Requirements-Rudder/Elevator

T-6A CONTACT

CHAPTER TWO

Rudder trim: an electromechanical actuator located in the vertical stabilizer , which drives an

anti-servo trim tab on the trailing edge of the rudder provides rudder trim. Reference the balance

ball of the turn and slip indicator to help determine the proper direction of rudder and rudder trim

pressure. For example, if the ball is out to the right, the nose is actually out to the left and you

are in unbalanced flight. Smoothly apply right rudder pressure ("Step On The Ball") to regain

balanced flight. Then smoothly apply right rudder trim until you relieve the rudder pressure you

are holding. If you have trimmed properly, the ball should stay in the center and you should feel

as if you are flying straight and level.

TAD: the rudder TAD of the T-6A assists in trimming about the yaw axis of the aircraft. The

inputs to the TAD include engine torque, altitude, airspeed, and pitch rate. Based on these

inputs, the TAD sends a signal to the rudder trim actuator physically moving the trim tab surface

to a computed position. Although the TAD is effective at approximating a valid rudder trim

position, it by no means replaces the need to appropriately trim the rudder, especially during

rapid accelerations and large power changes.

Remember any pilot-actuated electric rudder trim inputs are additive to the trim input the TAD

commands. Thus, a good technique during minor trim changes is to allow the TAD to complete

its trim cycle, then make fine adjustments as necessary. Loss of the TAD in flight does not affect

the overall controllability of the aircraft and its loss would minimally impact most training

missions.

Elevator trim: elevator trim is provided by an electromechanical actuator which drives a tab

surface on the right side of the elevator. To trim the aircraft nose attitude, first move the stick to

position the nose for the attitude you desire in relationship to the horizon. As the fore/aft stick

force increases, maintain the desired nose attitude and apply elevator trim in the opposite

direction as the control pressure until it is relieved. Always use a light grip on the stick so as to

"feel" the pressure. "Finger-tip control" is the key to smooth flying.

Aileron trim: the aileron trim is utilized much like the elevator trim but about the longitudinal,

or roll, axis of the aircraft. Interestingly, unlike the other two trim systems that utilize trim tab

surfaces on their training edges (rudder and elevator), aileron trim in the T-6A is accomplished

by physical movement of the ailerons. Ground adjustable trim tabs are installed on the trailing

edge of each aileron to allow maintenance personnel to adjust the "neutral" setting. Aileron trim

is only necessary if, after the rudder is trimmed, the aircraft tends to roll to one side.

203.

TRIM REQUIREMENTS - RUDDER/ELEVATOR

Acceleration

LEFT/DOWN

Deceleration

RIGHT/UP

Power Addition

RIGHT/DOWN

Power Reduction

LEFT/UP

THE FLIGHT CONTROLS

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