oral study guide Flashcards
when placing the IRS to NAV position, what does the ON DC light mean
IRS powered by the DC bus
What would cause the Align lights to flash
no present position
incorrect position
aircraft moved during alignment
fault
if DC fail light comes on with AC power available, is this a problem
no, but DC power is not available
what electrical system powers the IRU
Standby bus
what hydraulic system powers the normal brakes
right system
what hydraulic system powers the reserve brakes
center system
what system is used for gear and flaps
center system
when do the demand pumps come on
auto positon-when needed
on position-always
the RAT powers which hydraulic system when activated
center
how long is the main battery capable of powering the standby power system
30 min (90 min with 2 discharge lights BAT and APU)
on standby power, what effect will battery depletion have on the gear and flaps
ADP in center hydraulic system requires DC power to operate. when ADP quits, there will be no center gydraulic system pressure, therefore no way to operate gear and no flaps hydraulically (ADP air supply valve will close when DC power is lost)
Purpose of the bus tie system (PPI123)
P-prevents paralleling of L or R main buses
P-provides power to both main buses
I-isolates faults
1- allows DC bus tie breaker to close with loss of DC power
2-allows Capts flight insturment to remain powered with loss of left AC bus
3-allows F?Os flight insturments to remain powered with loss of right AC bus
Utility bus load shedding (BOSS)
Both thrust levers advanced to takeoff range on the ground with engines shutdown
Overload(electical load exceeds power avaiable)
Starting engines
Single geneator source
with a LEFT AC bus fault, will Capts flight instruments fail?
No, automatically powered from R main AC bus
when is the ground handling bus powered
on tround with external power connected or grom APU generator
what items are normally powered by ground service bus
main battery charger
APU battery charger
misc cabin systems
normal souce of power for for ground service bus
right main AC bus
alternate souces of power for ground service bus
APU Generator
external power
What happens to the electical system once engines are started and external or APU electical power was in use
IDG automatically powers respective main bus and previous power source is disconnected from that bus
whe dose the HDG (hydrolic driven generator) activate automatically
L and R AC buses are unpowered
which hydraulic system drives the HDG
Center
HDG provides power to
battery and hot battery buses
standby AC and DC buses
L and R AC trasfer buses
Captians flight instument transfer bus
how can the FOs flight instruments be powered by the HDG
ALTN on the FLT INSTR BUS PW switch
How is fuel supplied to APU when AC power is available
Left FWD AC fuel pump
