PTM Ch. 15 Flight Controls Flashcards
What are the primary flight controls?
Ailerons, rudder, and elevators
How are control inputs transmitted to the flight control surfaces?
Through cables, push-pull rods, and bellcrank-actuated trim tabs
What is attached to the forward side of the control column to apply a nose down preload on the pitch control system?
Bob weight
How does the control lock work?
Lock pins are mechanically inserted into the actuating linkage of the rudder and ailerons, and both power levers are restricted to the aft of FLT IDLE.
The control lock system is…?
Fail-safe
What does it mean when the control lock system is fail-safe?
Lock pins are spring-loaded to disengage if the control lock cable breaks.
Why can’t the control lock be engaged in flight with the power levers forward of ground idle?
Mechanical blockage of by the power lever linkage.
How can the elevator be secured on the ground?
Using a seat belt extension to hold the control column fully aft.
The trim tabs also function as…?
Servo tabs
Are there trim tabs on the elevators?
No
How is pitch trim accomplished?
By moving the horizontal stabilizer
How is the horizontal stabilizer moved?
An actuator containing two DC motors and two screwjack mechanisms
Where is the pivot point for the horizontal stabilizer?
Near the stabilizer rear spar.
The motor on the pilot’s side is controlled by what?
Left essential bus
The power to the trim motor on the copilot’s side (controlled with the copilot’s trim switch and AUX switch) is powered by what?
Right essential bus
The out-of-trim warning shouldn’t work in the air because of what?
A squat switch
What kind of flaps does the Metro have?
Double slotted Fowler flaps
How do the flaps work?
Electrically controlled and hydraulically actuated.
What prevents asymmetrical operation of flaps?
Mechanical interconnection between left and right flaps.
What supplies power for flap control and indication?
Non essential bus
In case of an electrical or hydraulic failure where will the flaps remain?
In their last position.
What should you do if the flaps don’t operate properly?
Move the flap lever to the full UP position.
What does moving the flap lever to the UP position do?
The circuit is direct, bypassing the circuit and permitting retraction in the event logic circuits fail.
What does the input to the two SAS computers come from?
Flap position
Power levers position
G-loading
AOA
How is AOA measured?
By SAS vane(s)
What arms the SAS at lift-off?
Squat switch
When does the stick pusher activate?
About 1 knot above stall speed
How much force is applied by stick pusher?
65 lb
Protection from stalls at higher than normal entry rates is provided by what?
“Advancement” circuit that ensures all warning devices operate at lower than normal angles of attack.
What activates the “advancement” circuit?
Forward movement of either power lever beyond 1/2 travel.
When will the amber SAS SERVO FAIL annunciator illuminate?
Power to stick pusher is interrupted
SAS Servo switch off
Negative G-loads
Failure of servo itself
When would a L or R amber SAS FAIL annunciator illuminate?
If the respective computer loses power or if the SAS vane is moved full up when on the ground.
Is the SAS required for all flights?
Yes
When must the pitot heat/SAS heat be selected ON?
Icing conditions (visible moisture below 5 dC)
The flaps are held in any position by what?
A liquid lock created by the selector valve and the flap lock valves
