Flight Controls Flashcards
Stabilizer Trim Cut Out Switches - Cut out
Shuts off the respective center or right (left or center -767) hydraulic system power to the related
stabilizer trim control module
Speed Brake Light (amber)
Speedbrakes extended and:
• Flaps are in a landing position, or
• Radio altitude is 800 feet or below
Flap Lever Positions (757)
1 -
• Slats extend to the midrange (takeoff) position
• Flaps extend to 1
5, 15 AND 20 -
• Slats remain in the midrange position
• Flaps extend to the commanded position
- Flap Gate at 20
25 -
• Slats extend to the fully extended (landing) position
• Flaps extend to 25
30 -
• Slats remain in the fully extended (landing) position
• Flaps extend to 30
• Flap load relief system arms
Leading Edge/Trailing Edge Light (amber)
- Flap disagree exists
- Flap asymmetry exists
- Flap load relief system is not operating when required (Trailing Edge)
Alternate Flaps Arms Switches
ALTN -
• Arms the selected LE slat or TE flap alternate drive unit
• Shuts off hydraulic power to both the flap and slat drive systems (757)
• Shuts off hydraulic power to the selected LE slat or TE flap drive systems (767)
How is control maintains if flight controls are jammed
pilots can maintain control by applying force to the other column or wheel
to overcome the jam
How many flight control surfaces (pitch, roll, yaw)
Pitch:
- 2 elevators
- movable horizontal stabilizer
Roll:
- two ailerons
- 12 x spoilers (2 for ground use only)
Yaw:
- single rudder
How are elevators controlled?
- control column signals hydraulic actuators (R,L,C/C,L,R) to move elevator surfaces
- elevator feel units powered by center and right (left and center - 767) HYD systems
- mechanical springs as back up
How many modes of horizontal stabilizer control?
3
• Electric
• Alternate
• Automatic
How is stabilizer trim controlled?
- powered by center and right (left and center -767) hydraulic systems
- trim switches send position commands to horizontal trim control modules (2)
When is the horizontal stabilizer automatically trimmed
- by autopilot when engaged
- Mach speed trim system when AP not engaged (improves speed stability by trimming stabilizer as speed changes)
- only one trim control module and trims at one-half normal rate
How is roll controlled? (757)
- Control wheel signals actuators (two actuators per aileron - R,C/C,L) to move single aileron surface on each wing
- spoilers also extend to augment roll control
How is yaw controlled? (757)
- Single rudder surface driven by 3 actuators
- each actuator driven by a different hydraulic system
Rudder Ratio System
- protects the rudder surface by desensitizing pilot input and reducing deflection as airspeed increases
- receives ADC inputs and controls an actuator to dampen pilot input
- actuator powered by left hydraulic system
Yaw Damper system
- 2 yaw dampers
- controlled by L and C hydraulic systems
When do Spoilers automatically move to UP?
ARMED:
- landing gear fully on the ground (no tilt)
- thrust levers idle
Not ARMED:
- landing gear fully on the ground
- thrust levers moved to idle detent
SPEEDBRAKES light/SPEEDBRAKES EXT EICAS
Speedbrakes extended, and:
- flaps in landing position, or
- below 800’ RA
How many spoiler panels and which are used for air/ground purposes?
12 total spoiler panels(6 per wing) - 1,2,3,4-5,6 7,8-9,10,11,12
4 and 9 are for ground use only
How are Slats/Flaps driven (757)
- two power drive units (PDUs)
- one for dedicated to slats and one dedicated to flaps
- powered by left hydraulic system
Purpose of Autoslats
- enhance aircraft stall characteristics
- if signal from stall warning system received slats automatically extend from midrange to full
Selecting ALT Flap switches
- Disable normal control
- Arm the alternate mode
- Engage the electric motors
- Flap lever no longer controls flaps/slats
- Allow independent selection of either flaps or slats (767)
- limited to Flaps 20
- flap load relieve, autoslats, and asymmetry protection are not avail
Which EICAS messages would have hydraulic power to both flaps and slats shutoff?
LE SLAT DISAGREE, TE FLAP DISAGREE, LE SLAT ASYM, and TE FLAP ASYM
Flap Lever Positions (767)
UP - Slats and flaps are retracted
1 -
• Slats extend to the midrange (takeoff) position
• Flaps remain retracted
5 -
• Slats remain in the midrange (takeoff) position
• Flaps extend to the commanded position
• Inboard ailerons droop in conjunction with flap extension from 1 to 5 degrees
15 AND 20 -
• Slats remain in the midrange (takeoff) position
• Flaps extend to the commanded position
- Flap Gate at 20 for Go-Around protection
25 -
• Slats extend to the fully extended (landing) position
• Flaps extend to 25
• Flap load relief system is armed
30 -
• Slats remain in the fully extended (landing) position
• Flaps extend to 30
How is Roll Controlled (767)
- Four ailerons (2 x inboard, 2 x outboard)
- 12 x spoilers (all for ground and air use)
What is Pitch Enhancement System (767)
- activates if left and center hydraulic systems are lost in flight
- hydraulic motor uses trapped left system trim fluid to operate stabilizer
- only electronic trim avail at 1/4 rate
Aileron Lockout (767)
- permits full travel of the outboard ailerons at low speeds and locks out the outboard ailerons at high speeds
- outboard aileron lockout at 280 knts
- outboard aileron unlock at 240 knts
Flap Load Relief
757:
If Flap placard speed is exceeded in Pos 30 (162)…flaps auto retract to 25
767:
If Flap placard speed is exceeded in Pos 25 (180) or 30 (170)…flaps auto retract to 20
Speedbrake Load Alleviation system - LAS (767)
Activated in flight:
• Flaps are UP
• Gross weight is greater than 340,000 lbs
• Indicated airspeed is greater than 320 knots
- restricts speedbrake to 50%
What happens to roll control during a loss of center hydraulics and a loss of either left or right hydraulics?
- an unpowered, floating aileron
- May result in undesirable lateral yoke displacement to maintain wings level
AIL LOCK Amber message (767)
Aileron lockout actuator not in signaled position
− At high speed, avoid abrupt control wheel inputs
− At low speed, roll rates may be reduced
Stab Trim Rates
Full: Normal or alternate stabilizer trim activated during manual flight
One-Half:
− Autopilot engaged – or –
− One trim motor inoperative
One-Quarter: PES operating (767)
