TECH Flashcards
Can you explain sources of electrical generation and their priorities
“GEAR-B”
G- GENs
E- External Power
A- APU
R- RAT
B- BAT
In flight, in norm ops which generator has the higher load and why?
the GEN1
because it feeds the AC ESS BUS (?)
what does the emergency gen cover?
DC ESS + AC ESS
approximately how long does it take for the emergency gen to come online and during that time what is powering the aircraft and with that power what is it powered on the flight deck?
8 seconds
in the meantime Batteries are powering the PFD1, Upper DU and FMGC1.
basically what we need to fly an aircraft (Pitch and Power)
what is the purpose of EMER ELEC GEN 1 LINE on the overhead panel?
To energize the Fuel Pumps n.1 during the Smoke configuration. Otherwise in EMER ELEC we have gravity feeding.
Technically:
GEN 1 LINE contactor opens. GEN 1 remains running and supplies 1 fuel pump in each wing tank. AC BUS 1 is supplied by GEN 2 through the bus tie contactor
approximately what Spd must be maintained for the RAT?
140kt
what is the diff between selecting the gen off and the IDG off?
IDG disconnect all the drive generator (including generator) and cannot be reverted.
GEN PB disconnects only the generation part of the IDG (not the drive and the cooling)
what is the purpose of selecting the APU master switch ON the overhead panel in the REMOVAL OF SMOKE/FUMES QRH checklist?
IN EMER ELEC if you press the master sw the battery contactors will close for a max of 3’ allowing the crew to manually control the outflow valve that is powered by the DC BAT BUS.
under what circumstances will the RAT extend automatically
AC BUS 1+2 FAULT (>100kt)
at what altitude can the APU be started in the EMER ELEC CONFIG and why
Below 250
To preserve battery power
under normal ops what altitude can the APU support Electrical load and Bleed demand?
22500’ single pack
15000’ dual pack
Name the sources of power of each of the HYD systems
Green: ENG 1 pump
Blue: B Elec Pump + RAT
Yellow: ENG 2 pump + Y Elec pump
what services does the GREEN SYS power
slats&flaps, 2 pairs of spoilers, ailerons, THS, L elevator, Rudder, L/G, Normal Braking
what services does the YELLOW SYS power?
2 pair of spoilers, flaps, THS, R elevator, rudder, Alternate BRK
what services does the BLUE SYS power?
slats, 1 splr, 1 aileron, both elevators, rudder
why on the HYD SYS page in flight is the green reservoir lvl always showing slightly less than the other 2?
cause the fluid is being used to retract the landing gear (?)
how are the HYD reservoirs pressurized and why?
with HP bleed air from engine 1. If bleed pressure is too low then the system takes from the crossbreed duct.
The aim is to prevent pump cavitation.
what is the purpose of the HYD priority valves?
cut off hydraulic power to heavy load users if hydraulic pressure in a system gets low
what is the purpose of the HYD accumulators
helps to maintain a constant pressure by covering transient demand during normal ops
explain the purpose of the PTU
enables the yellow system to pressurize the green and vice-versa (no fluid exchange).
what is the typical sys pressure for the three hyd systems and what pressure do you expect to see when the RAT is powering the system
normal: 3000 PSI
RAT: 2500 PSI
at what point does the system pressure become AMBER?
PSI < 1450
of the dual HYD failures which in your opinion is the worst and why?
G+Y: extremely long landing listance required because of loss of Flaps and braking norm and alternate (only accumulator available)
which of the dual hyd failures maintainins the aircraft in normal law?
B+Y