Airframe Structures: Assembly & Rigging 🔊

Question 1

What are three types of commonly used flight control systems?

Answer 1

Cable, the push-pull tube, and the torque tube systems

Question 2

What is used in large metal aircraft to keep control cable tension within acceptable limits?

Answer 2

A cable tension regulator

Question 3

What is a fairlead?

Answer 3

It is a cable guide that slightly deflects straight run cables.

Question 4

How much cable deflection is acceptable due to a fairlead?

Answer 4

3°

Question 5

Where does failure of control cables occur most frequently?

Answer 5

Where cables pass over pulleys and through fairleads.

Question 6

Which flight control surfaces are considered the primary group?

Answer 6

The elevators, the ailerons, and the rudder.

Question 7

Which flight controls are considered the secondary group?

Answer 7

The trim tabs, spring tabs, wing flaps, servo tabs, and the anti-servo tabs. (These do not alone cause the aircraft to move about any of its axes)

Question 8

Which flight controls are in the auxiliary group?

Answer 8

Trailing edge flaps, slats, slots, speed brakes, etc. (High lift devices for slow speed flight)

Question 9

How do wing flaps affect landing speed and approach angle of an aircraft?

Answer 9

The use of flaps increases the camber of a wing and therefore the lift of the wing, making it possible for the speed to be decreased without decreasing lift.

Question 10

What is a balance tab?

Answer 10

It is an auxiliary control with fixed linkage designed to move in the opposite direction as the primary surface. Aerodynamic forces acting on the tab assist the pilot in moving the control surface.

Question 11

What is a trim tab?

Answer 11

It is an auxiliary control attached to the trailing edge of the primary control surface that is positioned by movement of a cockpit control to reduce the workload on the pilot in maintaining a desired flight attitude.

Question 12

What is the purpose of the collective pitch control in a helicopter?

Answer 12

It is used to change the pitch of the main rotor blades therefore increasing or decreasing lift.

Question 13

Why is it important for the blades of a helicopter rotor system to be tracked?

Answer 13

To reduce vertical vibrations

Question 14

What is the most efficient way to check a helicopter rotor for dynamic balance?

Answer 14

The use of a balance/analyzer computer

Question 15

What unit on a helicopter is used to compensate for torque created by the main rotor?

Answer 15

The tail rotor

Question 16

What control operates the helicopter tail rotor?

Answer 16

The anti-torque pedals

Question 17

What are the three axes of an aircraft and which control surfaces cause the aircraft to move about each axis?

Answer 17

Longitudinal (from nose to tail) uses ailerons for roll; Lateral (from wingtip to wingtip) uses elevators for pitch; Vertical (passes through the center from top to bottom) uses the rudder for yaw

Question 18

When installing an aircraft bolt, what precaution would you take regarding the position of the bolt?

Answer 18

The bolt head should be positioned on top when installed vertically or forward when installed horizontally.

Question 19

How is the propeller torque corrected for during assembly and rigging in some single engine aircraft?

Answer 19

Some aircraft have the leading edge of the vertical stabilizer offset to the longitudinal center line to counteract engine torque.

Question 20

What reference publications should be used to rig aircraft, including the control system?

Answer 20

Refer to the Aircraft Specifications or Type Certificate Data Sheets issued by the FAA and the maintenance manual issued by the manufacturer

Question 21

What are vortex generators?

Answer 21

Small airfoils mounted on the upper surface of wings. They dampen shock-induced separation of the airstream which results in a stall.

Question 22

What is a servo tab?

Answer 22

A cockpit controlled adjustable tab attached to the trailing edge of a primary control surface.

Question 23

What factors are used to determine the proper cable tension?

Answer 23

The size of the cable and the outside temperature.

Question 24

Why do control surfaces need to be statically balanced?

Answer 24

Out of balance control surfaces can cause severe flutter

Question 25

What is a spring tab?

Answer 25

A flight control that uses a spring to assist control surface movement at high speeds.

Question 26

What tool can be used to measure control surface travel?

Answer 26

A protractor

Question 27

What does a helicopter cyclic do?

Answer 27

It controls the main rotor in order to change the helicopter’s direction of movement. In a hover, the cyclic controls the movement of the helicopter forward, back, and laterally.