B-757-200-300 Oral System Review study guide Flashcards
Electrical Panel + System Load Shed
Types of Load Shed:
1- Inflight Generator Loss- Auto reset w/ 2gen
2- Flight Load Shed- Respective utility bus to the overloaded generator is shed (manual reset req)
3- Ground load shed- same as flight, may be progressive starting with galleys then utility
4- Engine start- w/APU running, both utility busses will shed on 1st engine start, respective bus shed on the 2nd engine start (auto reset)
APU
Run light- APU operating, flashes twice during starting. Remains illuminated at shutdown bc cooling.
Fault light- Indicates fault, or fuel valve not in commanded position (in transit)
Switch/selector:
OFF- closes bleed valve, initiates shutdown, resets fault circuitry
ON- APU operating position, opens door, arms bleed alve, energizes fuel pump
START- Initiates auto start, spring loaded to ON. Starts APU up to 43,000’ (35,000’ desired). Compressor supples pneumatic power up to 17,500’
Emergency Lights
OFF- Prevent activation of emergency lights system when airplane electrical power fails
ARMED- All interior and exterior emergency lights illuminate automatically if DC power fails or is turned off
ON- all emergency lights illuminate
UNARMED light- indicates the emergency lights switch is not in the ARMED position
Engine ignition/Start selectors
Ignition selector- selects No.1, both or No. 2 ignitors on both engines
Start valve light- Illuminates if valve not in commanded position
Start selector:
GND- Opens start valve, arms ignition
AUTO- Selector releases to AUTO at 50% N2, closes the start valve. Selected ignitors operate when flaps out of the UP position or Engine anti ice on
OFF- Ignition off unless rapid movement of thrust lever
CON- selected ignitors operates continuously
FLT- both ignitors operate continuously
Engine start duty cycle
Normal start- 2min ON, with n2 decreasing to zero, 3 attempts, then 15min cooler period.
Extended start- 4min ON, with 15min cooling period between each attempt.
IRSs
ON DC light- IRS is operating on DC power eventually causes ground crew call horn to sound if battery off
Loss of AC power:
ETOPS plane- All three IRS switch to DC power. Right IRS shuts down after 5min
Yaw damp
INOP light:
On ground- Indicates IRS signal are not preset or not aligned or switch is OFF
in flight- indicates hydraulic failure or fault in Yaw Damper controller or no IRS Signal. Rudder authority is reduced to half. Powered by the L & C hydraulic system
Left hydraulics
Powers:
Landing gear, nose wheel steering, flaps & slats, rudder ratio, yaw damp, L thrust reversers, Alternate brakes, spoilers, L A/P servos, Elevator, rudder and Right aileron
HDG- back up AC power source, non time limited. Powers 7 buses: Capt Flt instruments, Xfer bus, L&R AC xfer buses, AC + DC standby buses, battery and hot battery bus
Right Hydraulic System
Powers:
Rudder elevator feel, Right thrust reverser, STAB trim, spoilers, R A/P servos, elevator, Normal brake, and left aileron
-powers PTU, which automatically operates if left system egine driven output press is low. Provides pressure for: Flaps/slats, landing gear, nose wheel steering. PTU uses left hydraulics, powered by right hydraulics.
Center Hydraulic system
Powers:
Rudder, spoilers, C A/P Servos, ailerons, elevator
Contains RAT- auto deploys w/ duel engine failure. Must maintain 130kts
-two electric hydraulic pumps
Battery
BAT discharge light-
Indicates main battery is discharging. AC w/HDG installed is illuminated until battery discharges to equal that of HDG output
STBY power switches
OFF- removes power from both the stby AC & DC BUSES
AUTO- Allows main battery to power the HOT BAT bus, BAT bus, STBY AC & DC busses
Fuel config light on if…
1- Low quantity. Less than 2,200 in main
2- fuel imbalance of 1,800lbs (1,950lbs is max)
3- center pumps off with more than 1,200lbs remaining in center tank
Min fuel temp
3 degrees above fuel used freezing temp. Jet A= -37
fuel temp is taken from right tank
fuel capacities
Main L&R= 15,450lbs (14,600 useable)
Center= 48,997lbs (46,200 useable)
