C-5 APU TEST QUESTIONS AND ANSWERS
Do not operate the APU w/ APU compartment door open unless... - Answers - an
external fire guard w/ adequate fire extinguisher is stationed at APU compartment
What is required when operating the APU/ATM sys in hangers NOT EQUIPPED w/
automatic fire suppression system (FSS)? - Answers - Two 150 lbs HALON fire
extinguishers; one near running APU/ATM and a major CRASH/FIRE/RESCUE (CFR)
vehicle must be on stanby outside the hangar.
One hangar door must be open how many feet? and for what reasons? - Answers - 50
Feet, to allow ventilation and if needed CFR vehicle access.
Left and Right APU start accumulatiors must be pressurized to a min of? - Answers -
2,800 PSI (at 0* F and above)
What is the MIN BATT voltage? - Answers - 22.5 VDC
What is the result of having an UN-serviceable battery installed and connected? -
Answers - Total deactivation of the fire fighting capabilities at the nose wheel well FSS
control panel.
How much fuel is needed and in which tanks for operating APU/ATM systems. Explain
why. - Answers - 4,500 lbs min in MAIN Tanks 2 and 3 for Hyd system operation plus
APU operating fuel. BONUS* Why HYD?
When will the audible warning horn be inoperative? - Answers - If the #1 touchdown
relay c/b is open or if the airplane is on jacks
At what time is it ok for a ground observer to attempt to fight a fire and through what
door? - Answers - Not until the APU start has been terminated and through the APU
push-in door
If there is no external power available for an APU start, what must be accompished? -
Answers - A fire truck must be standing by
If the APU is started without external power, what indication(s) will you not have? -
Answers - No fire detection or EGT indication
If during start the EGT indication of 715*C or elapsed time of 30 sec(0*C and above)
from start to ON SPEED lights illuminate is exceeded, what should be done? - Answers
- Terminate start immediately and do not attempt to restart until the malfunction has
been corrected
What are the APU operation limits? - Answers - 1) 0*C to 715*C starting normal
, 2) 715*C to 824*C for 20 seconds max transient limit during start
3) 691*C to 746*C 3 minutes max upon applying load at governed speed
4) 600*C to 691*C full load continous
What do you do if either batt is below the min voltage? - Answers - Replace batt if
available, if not available open batt C/B or disconnect connector to avoid damage to batt
when pwr is applied.
What is the range the DC volts meter shall indicate? - Answers - 25-30 VDC
During APU start up and operation what position must the battery switch be in and why?
- Answers - BATT switch must be in the ON position for fire handle shutdown and fire
extinguisher discharge.
The UHF/VHF radios will be set to the fequency that communicates with whom? -
Answers - Ground control/ control tower frequency
What is the FREQ meter on the AC SYS CONTROL PANEL supposed to indicate? -
Answers - 394 to 406 (400 +/- 6)
What is the AC volt meter on the AC SYS CONTROL PANEL supposed to indicate? -
Answers - 112 to 118 VAC (115 +/- 3)
What is the AC load meter on the AC SYS CONTROL PANEL supposed to indicate? -
Answers - 1.0
How many seconds do you leave the APU/OFF/EXT PWR switch to off before placing to
APU? - Answers - 2 Seconds
How long should you allow the APU to warm up before applying an air load? - Answers -
2 minutes
When starting ATM/PTU why should you check with the ground observer the position of
the flaps/slats in reference to the Flap handle? - Answers - Application of HYD power
will cause surfaces to move to position commanded by the handle setting.
When can you shut off the Electric Suction Boost pumps while opperating Hyd
Systems? - Answers - Never
Where must personnel be stationed when operating ATM's? - Answers - A qualified
operator must be at the FE station to monitor ATM operation.
During the start of an ATM what is the time limit for hydraulic pressure to reach
operating range? - Answers - 15 seconds
Do not operate the APU w/ APU compartment door open unless... - Answers - an
external fire guard w/ adequate fire extinguisher is stationed at APU compartment
What is required when operating the APU/ATM sys in hangers NOT EQUIPPED w/
automatic fire suppression system (FSS)? - Answers - Two 150 lbs HALON fire
extinguishers; one near running APU/ATM and a major CRASH/FIRE/RESCUE (CFR)
vehicle must be on stanby outside the hangar.
One hangar door must be open how many feet? and for what reasons? - Answers - 50
Feet, to allow ventilation and if needed CFR vehicle access.
Left and Right APU start accumulatiors must be pressurized to a min of? - Answers -
2,800 PSI (at 0* F and above)
What is the MIN BATT voltage? - Answers - 22.5 VDC
What is the result of having an UN-serviceable battery installed and connected? -
Answers - Total deactivation of the fire fighting capabilities at the nose wheel well FSS
control panel.
How much fuel is needed and in which tanks for operating APU/ATM systems. Explain
why. - Answers - 4,500 lbs min in MAIN Tanks 2 and 3 for Hyd system operation plus
APU operating fuel. BONUS* Why HYD?
When will the audible warning horn be inoperative? - Answers - If the #1 touchdown
relay c/b is open or if the airplane is on jacks
At what time is it ok for a ground observer to attempt to fight a fire and through what
door? - Answers - Not until the APU start has been terminated and through the APU
push-in door
If there is no external power available for an APU start, what must be accompished? -
Answers - A fire truck must be standing by
If the APU is started without external power, what indication(s) will you not have? -
Answers - No fire detection or EGT indication
If during start the EGT indication of 715*C or elapsed time of 30 sec(0*C and above)
from start to ON SPEED lights illuminate is exceeded, what should be done? - Answers
- Terminate start immediately and do not attempt to restart until the malfunction has
been corrected
What are the APU operation limits? - Answers - 1) 0*C to 715*C starting normal
, 2) 715*C to 824*C for 20 seconds max transient limit during start
3) 691*C to 746*C 3 minutes max upon applying load at governed speed
4) 600*C to 691*C full load continous
What do you do if either batt is below the min voltage? - Answers - Replace batt if
available, if not available open batt C/B or disconnect connector to avoid damage to batt
when pwr is applied.
What is the range the DC volts meter shall indicate? - Answers - 25-30 VDC
During APU start up and operation what position must the battery switch be in and why?
- Answers - BATT switch must be in the ON position for fire handle shutdown and fire
extinguisher discharge.
The UHF/VHF radios will be set to the fequency that communicates with whom? -
Answers - Ground control/ control tower frequency
What is the FREQ meter on the AC SYS CONTROL PANEL supposed to indicate? -
Answers - 394 to 406 (400 +/- 6)
What is the AC volt meter on the AC SYS CONTROL PANEL supposed to indicate? -
Answers - 112 to 118 VAC (115 +/- 3)
What is the AC load meter on the AC SYS CONTROL PANEL supposed to indicate? -
Answers - 1.0
How many seconds do you leave the APU/OFF/EXT PWR switch to off before placing to
APU? - Answers - 2 Seconds
How long should you allow the APU to warm up before applying an air load? - Answers -
2 minutes
When starting ATM/PTU why should you check with the ground observer the position of
the flaps/slats in reference to the Flap handle? - Answers - Application of HYD power
will cause surfaces to move to position commanded by the handle setting.
When can you shut off the Electric Suction Boost pumps while opperating Hyd
Systems? - Answers - Never
Where must personnel be stationed when operating ATM's? - Answers - A qualified
operator must be at the FE station to monitor ATM operation.
During the start of an ATM what is the time limit for hydraulic pressure to reach
operating range? - Answers - 15 seconds
