Week 3 Part 1 Flashcards
What type of APU is installed on the G650?
RE220
What altitude will the APU provide electrical power up to?
45000ft
What altitude will the APU provide pneumatic power up to?
45000ft
What is the max APU EGT on start?
1050 degrees
What is the max APU EGT during operation?
732 degrees
What percentage RPM does over speed protection kick in at?
106%
What are the 4 APU drains? (EBIF)
- enclosure
- bearing witness
- inlet plenum
- fuel control
What clearance is required around the APU exhaust nozzle?
0.075”
Which cowl open switch inhibits APU start?
Right
How long will the APU continue to run if you remove panels?
10 mins
Will the APU start with panels removed?
No
What signal determines whether the APU is in normal or essential modes?
WOW from the LGCU
When will the APU be in ESS mode?
If something that would have caused shut down on the ground happens in flight
What power source does the APU use for start on the ground?
Left battery
What PSID does the APU fuel bypass DPI pop at?
7.5 psi
What does the APU sit on in the APU bay?
Teflon rails
What is the APU enclosure made from?
Titanium
What side of the aircraft is the APU exhaust?
Right
Where is the APU surge control valve exhaust?
Within the main APU exhaust
What provides 100% in flight start recovery no later than what attempt?
2nd
Where is the APU ECU?
Forward BEER
When is the APU nite performed?
When master selected on
If APU is in ESS mode in flight, how long will it stay that way after landing?
15 mins
When the APU is selected off, how long is 28V DC power latched for?
5 mins
When does the APU starter cut out?
46% RPM
Where is the APU fuel SOV?
Left hopper
When does the APU fuel shut off solenoid open during start?
5% RPM
What is APU gearbox capacity?
5.10 quarts
What gearbox oil level initiates protective shutdown?
<2.&5 quarts
What temp does the APU oil temp sensor extend starter engagement to adjust for oil viscosity?
-23.3 degrees
What temp does the oil temp sensor shut down the APU in non ESS mode?
> 149 degrees
What position is the APU fuel flow divider at 5% and 25% RPM?
- 5% - closed to ensure all fuel to primary manifold
- 25% - open to split fuel between primary and secondary manifold
How many fuel atomisers in the APU combustion chamber?
10
Above 30000 feet, when fuel demands are low, what does the APU fuel flow divider do?
Closes
What pressure does the fuel high pressure relief valve trip on shutdown? (Allows fuel back to pump inlet)
250psi
What does the gearbox PRV regulate oil pressure at? What pressure does it relieve excess pressure?
- 67 +/- 7.5
- 240 +/- 40
When does the APU oil deprime solenoid operate?
- open at
If the oil deprime solenoid is stuck open, when will this cause an APU shutdown?
Non ESS mode
When does the APU oil pressure switch cause APU shutdown is non essential mode?
<30psi for >15 seconds
What does the APU surge control valve do?
- vents compressor discharge air above 16500 feet
- opens at 70% RPM when trying to start above 19,200 feet and
What do red and gold mean with regards to starter brush wear indication?
- red good
- gold bad
At 60% RPM, if the starter is not disengaged, what happens?
APU starter engaged CAS and aborted start
How Longdown you have to leave it before APU start attempts?
15 mins
What is the APU ignition unit output?
3000 volts
At _% RPM, APU ignition burst mode is in effect for 5-6 seconds, then _____ mode is in effect for the remainder of the start sequence
- 5
- maint
The APU monopole (speed sensor) is a _________ generator. It provides ___ speed signals to the APU ECU
- frequency
- two
What happens if you lose one and both speed signals from the APU monopole?
- one = blue CAS
- two = shut down in all modes
If you lose both EGT thermocouples, what happens in both ESS and non ESS modes?
- non-ESS shuts down
- ESS no shutdown and defaults to a 260 degree fuel schedule
When does the APU hourmeter come online?
95% RPM
If replacing the APU hourmeter, what happens to APU calculations?
Take removed hourmeter shouts and add to new running total
In ESS mode, when is ignition terminated?
98% RPM
Can you dispatch with a failed APU?
Yes but must have 2 good IDG’s and a RAT. Also no extended range ops