11.9 Flashcards
What’s manoeuvre load control
Using control surfaces to move the centre of lift inboard during manoeuvres so that the bending moment is reduced so there’s a reduction in load on the wing
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As the root is thicker so it can take the loads compared to the outer wing
Why are cable operated systems often used
Strong
Lightweight
And food at transferring loads over a large distance
Why are cable operated systems often used
Strong
Lightweight
And food at transferring loads over a large distance
What size control cables are usually used in aviation
7x19 flexible
7x7 flexible
What’s the purpose of the guards on the pulleys
Close fitted guards that prevent jamming or cables slipping off when they slacken due to temp changes
How accurate is a tensiometer
98%
What do tension regulators do
Allows cable under all conditions like expansion and contraction of cable and aircraft to be taken in and out equally to maintain uniform tension
What’s a disadvantage of a push pull control rod
What’s there overall advantage
Heavy weight and harder to route without complicating the control system
They can accept both push and pull loads without a parallel system
What are bell cranks used for
Used in conjunction of control rods and are frequently used to change direction
What are bell cranks used for
Used in conjunction of control rods and are frequently used to change direction
When are torque tubes used
When a twisting motions needed in a control system
Eg. Ailerons flaps slats
What are screwjacks used for
Moving surfaces that experience extreme aerodynamic loads like horiz stab and leading and trailing edge flap
What two critical functions do PCU’s do
They position the flight control surface in a response to mechanical or electrical commands
Represent a principle structural element capable of withstanding flight loads and providing protection against flutter
What two sections is the servo control unit divided into
Power section
Distribution section
What two sections is the servo control unit divided into
Power section - converts the hydraulic pressure to mechanical force
Distribution section
What are the two main operating MODES of the servo control unit
Control or active mode
Damping mode
What’s the damping mode of the servo control unit used for
A gust damper for control surfaces when the ac is on the ground
What are manual ans power assisted flying controls known as
Reversible flying controls
Can the pilot still move the controls on the event of a hydraulic failure in a power assisted control system
Yes
What do screw jacks do
Convert rotary motion to linear travel
What’s the reason for not utilising pneumatics to its full potential for flying control systems
Bc aids compressible
What mode is the electronic pcu in operation at below cruise speed
Normal mode
When there’s a single hydraulic or electric failure on the pcu what modes selected
Bypass
When there’s a single hydraulic or electric failure on the pcu what modes selected
Bypass
