Aero Ii Ch. 8

Front 1

State the type of control system used in the T-34C.

Back 1

conventional
utilize control surfaces to create different airplane motions, such as yaw,
pitch, and roll.

Front 2

Describe how the control surfaces respond to control inputs.

Back 2

Elevator
o Moving the control stick forward causes the elevator to move down,
forcing the tail on the airplane up and pitching the nose down.
• Ailerons
o Ailerons move in unison in opposite directions.
o If control stick is moved left, the left aileron rises, the right aileron lowers
and the plane rolls left.
• Spoilers
o Disrupt the airflow over the top of the wing in order to decrease lift on the
wing and cause the wing to roll downward.
• Rudder
o Stepping on the right rudder pedal moves the rudder to the right, pushing
the tail left and yawing the nose to the right.

Front 3

Describe how the trim tab system holds an airplane in trimmed flight.

Back 3

Trimming reduces the forces required to hold control surface in a position
necessary to maintain a desired flight attitude.

Front 4

State the T-34C trim requirements for various conditions of flight.

Back 4

Aileron trim
o in the T-34 is adjusted after takeoff and seldom requires further
adjustment during flight. Only the left aileron trim tab moves. The right
aileron trim tab is preset by maintenance.
• Right Rudder Trim
o is required for power increases and slower airspeeds.
• Left Rudder Trim
o is required for power reductions and faster airspeeds
• Elevator Trim
is adjusted up at slower airspeeds and down at higher speeds.

Front 5

State the point around which control surfaces are balanced.

Back 5

The forces that act at the control surface’s center of gravity and aerodynamic
center must be balanced around the hingeline in order to regulate control pressure,
prevent control flutter, and provide control-free stability

Front 6

Define mass balancing and aerodynamic balancing.

Back 6

Aerodynamic Balance
o Used to keep control pressures (associated with higher velocities) within
reasonable limits.
o As trailing edge of the control surface is deflected in one direction, the
leading edge deflects into the airstream forward of the hingeline.
o The force on the leading edge creates a moment that reduces the force
required to deflect the control surface, so the pilot may control the airplane
more easily.
Mass Balancing
o To gain a balance between control response and stability, the T-34 control
CG’s are located on the hingeline.
o Technique used to locate the CG on the hingeline, weights are placed
inside the control surface in the area forward of the hingeline (shielded
horn and overhang).

Front 7

State the methods of mass balancing and aerodynamic balancing used by each
control surface on the T-34C.

Back 7

For aerodynamic balancing, the T-34 and T-37 uses shielded horns on the
elevator and rudder, and an overhang on the ailerons.
• Mass Balancing
o To locate the CG on the hingeline, weights are placed inside the control
surface in the area forward of the hingeline (shielded horn and overhang).

Front 8

Describe how trim tabs can provide artificial feel.

Back 8

Servo Trim Tabs (ailerons) provide artificial feel by moving in opposite
direction as the aileron, thus helping the pilot deflect the aileron and making the
airplane easier to maneuver.
Anti-Servo Trim Tab (rudder) provides artificial feel by moving in the same
direction at a faster rate. Thus, the more that a rudder pedal is pressed, the greater
the resistance that the pilot will feel.
• Neutral Trim Tab (elevator) maintains a constant angle to the elevator when the
control surface is deflected

Front 9

State the purpose of bobweights and downsprings.

Back 9

Bobweights
o Increases the force required to pull the stick aft during maneuvering flight.
• Downspring
o Increases the force required to pull the stick aft at low airspeeds when
required control pressures are extremely light.

Front 10

State the artificial feel devices used by each control surface on the T-34C.

Back 10

Servo Trim Tabs (ailerons)
• Anti-Servo Trim Tab (rudder)
• Neutral Trim Tab (elevator)