Airframe Structures: Assembly & Rigging 🔊 Flashcards
What are three types of commonly used flight control systems?
Cable, the push-pull tube, and the torque tube systems
What is used in large metal aircraft to keep control cable tension within acceptable limits?
A cable tension regulator
What is a fairlead?
It is a cable guide that slightly deflects straight run cables.
How much cable deflection is acceptable due to a fairlead?
3°
Where does failure of control cables occur most frequently?
Where cables pass over pulleys and through fairleads.
Which flight control surfaces are considered the primary group?
The elevators, the ailerons, and the rudder.
Which flight controls are considered the secondary group?
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)
Which flight controls are in the auxiliary group?
Trailing edge flaps, slats, slots, speed brakes, etc. (High lift devices for slow speed flight)
How do wing flaps affect landing speed and approach angle of an aircraft?
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.
What is a balance tab?
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.
What is a trim tab?
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.
What is the purpose of the collective pitch control in a helicopter?
It is used to change the pitch of the main rotor blades therefore increasing or decreasing lift.
Why is it important for the blades of a helicopter rotor system to be tracked?
To reduce vertical vibrations
What is the most efficient way to check a helicopter rotor for dynamic balance?
The use of a balance/analyzer computer
What unit on a helicopter is used to compensate for torque created by the main rotor?
The tail rotor
What control operates the helicopter tail rotor?
The anti-torque pedals
What are the three axes of an aircraft and which control surfaces cause the aircraft to move about each axis?
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
When installing an aircraft bolt, what precaution would you take regarding the position of the bolt?
The bolt head should be positioned on top when installed vertically or forward when installed horizontally.
How is the propeller torque corrected for during assembly and rigging in some single engine aircraft?
Some aircraft have the leading edge of the vertical stabilizer offset to the longitudinal center line to counteract engine torque.
What reference publications should be used to rig aircraft, including the control system?
Refer to the Aircraft Specifications or Type Certificate Data Sheets issued by the FAA and the maintenance manual issued by the manufacturer
What are vortex generators?
Small airfoils mounted on the upper surface of wings. They dampen shock-induced separation of the airstream which results in a stall.
What is a servo tab?
A cockpit controlled adjustable tab attached to the trailing edge of a primary control surface.
What factors are used to determine the proper cable tension?
The size of the cable and the outside temperature.
Why do control surfaces need to be statically balanced?
Out of balance control surfaces can cause severe flutter
What is a spring tab?
A flight control that uses a spring to assist control surface movement at high speeds.
What tool can be used to measure control surface travel?
A protractor
What does a helicopter cyclic do?
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.
