11.9 Flight Controls Flashcards
What is the function of roll spoilers?
To extend on the wing with upward aileron deflection (down going wing) to give a more accurate turn on larger aircraft
How do ruddervator surfaces on V-tail aircraft provide pitch and yaw control?
- Both deflect up or down to control pitch
- One deflect up and one down to control yaw
What is the advantage and disadvantages of V-tail controls?
+Less weight as no vertical stab is required
- More surface area is required
- Cannot have full rudder and elevator extension at the same time
- Aircraft less stable
- Control surface adjustment more complicated due to combined inputs
How do elevons on delta wing aircraft control pitch and roll?
- Both surfaces move up or down simultaneously to control pitch
- One moves up and one down to control roll (aileron function)
What do secondary flight controls consist of?
- Lift Devices
- Drag Devices
- Trim systems
What 3 things can all flight control systems be divided into?
- Control Inputs
- Control transmissions
- Control surface outputs
What component is required to combine inputs from the rudder pedals and control column in a ruddervator (V-tail) system?
A mixer unit containing a gimbal
What does the flap lever control?
Flaps and slats
What are 2 the main components in a mechanical control run?
- Cables
- Rods
What 2 types of components do Hydraulic control systems use?
- Mechanical components
- Hydraulic components
What 3 types of components do electrical control transmissions use?
- Mechanical components
- Hydraulic components
- Electrical components
Through what 3 properties is a control cable identified?
- Diameter
- Number of strands
- Number of wires in each strand
Where are extra flexible control cables used?
In sections that require several changes of direction
What is the advantage and disadvantage of cables compared to rods?
+Less weight
-Cannot transmit push forces
What is the disadvantage of a mechanical control system with many connections?
There will be greater total play in the system from all the connectors so the transmission will be less accurate
What is an advantage of cables over rods when under excessive stress?
Cables will show evidence of failing before it fails completely (broken wires/strands etc) whereas a rod will fail suddenly
What can be used to remove old lubrication, grease and dirt from the surface of control cables?
A lint free cloth
What 3 things must cables be inspected for?
- Broken wires
- Worn areas
- Corrosion
What are the 3 main type of quadrants used to transmit push-pull rod forces to cables?
- Normal quadrants
- Single quadrants
- Tension regulators
What are single quadrants used for?
To transmit movement from a cable to several outputs simultaneously
What 3 things make up a tension regulator?
- 2 quadrant halves mounted on a common axle
- A spring loaded cross head mounted on a guide
- Pull rods
How does a cable tension regulator compensate for increased tension in a warm aircraft?
The quadrant halves rotate the pull rods, moves the cross head and compresses the springs
How does the cable tension regulator compensate for reduced cable tension in cold aircraft?
The springs press against the cross head and this force is transferred via the pull rods and the quadrant halves to the cables. The cable tension is restored to normal.
What are the six cable wear patterns that can be found on pulleys?
- Cable tension too high
- Cable misaligned
- Pulley misaligned
- Cable too small for pulley
- Blocked pulley
- Normal wear