C-17 Hydraulic System Exam
Questions And Correct Answers A+
Pass
How many hydraulic systems are there - Answer- 4
How much pressure does each system provide? - Answer- 4000 psi
When is any hydraulic system pressurized - Answer- When any system pump is
operating
What powers the primary and secondary hydraulic pump - Answer- Engine driven
When does secondary hyd pump go active - Answer- When the primary pump px falls
below 3400
When is aux activated - Answer- When both primary and secondary pump px falls below
3400
Where is No 1/2 Aux pump located - Answer- Left wheel well
Where are 3/4 aux pump - Answer- Right wheel well
What does the Hyd Xfer Pump do? - Answer- Permits mechanical transfer of pressure
between no. 2/3 systems
What function does the Xfer pump mainly serve? Where is it located? - Answer-
Ensures ability to gear retract or raise cargo door/ramp if lose engine 2/3. In right wheel
pod
What hydraulic system incorporates the RAT? - Answer- 4
What is function if RAT - Answer- Pressurizes system 4, located in right gear pod,
develops pressure to control aircraft in 4 engine flameout
On ground, what systems does LM functions require - Answer- 2/3
What does HSC do? How many HSCs are there? - Answer- Monitor temps/quantity
Monitor pump temps/pressure
Selects pumps
2 HSCs
HYD RES TEMP X - Answer- Above 121C
, Hot light - Answer- Case drain temp above 135C
HYD QTY X LOW - Answer- Qty falls below 3.3/6.4/3.9/3.3 when at or above 27C or
1.2/3.3/1.2/1.2 below 27C
HSC INOP - Answer- One of 2 HSCs failed. No auto sequencing of engine driven pumls
RUD TEMP LOW - Answer- Hyd reservoir indicates rudder IFCM may be below -6C.
Fluid below temp where rudder effectiveness may be degraded
At what temps in hydraulic system should takeoff never be attempted - Answer- Below
7C bc may be insufficient rudder deflection in engine fail on TO
How can you control transfer pump if switch light failed - Answer- From aft LM panel
How many hydraulic systems power each primary flight control - Answer- 2
What would happen to primary flight controls if one of the associated sys failed -
Answer- Would still operate but at a slower rate
When will aux pump automatically shut down? - Answer- Low quantity (0.4) or high
temp (>135)
How would aux pump fail be indicated - Answer- Low px light
How can failure of engine driven pump be indicated? - Answer- Low pressure or hot
light
How should you handle hot light on the ground? What should you do if you get a hot
light in flight? - Answer- Cycle flight controls but in flight turn of system
How can you tell transfer pump has failed - Answer- abnormal pressure in system being
pressurized
If you suspect transfer pump fail what should you do - Answer- Turn off the pump
What will happen if low quantity in sys 2/3 - Answer- Affected aux pump + Xfer pump
shut off
How are aux pumps driven - Answer- Electrically via an AC motor
How are HSCs powered - Answer- 1- bat bus 2-Dc bus 3
What is the EDV for? How does it work? - Answer- Depressurizes pump. Blocks pump
outlet and commands min flow (1100 psi)
Questions And Correct Answers A+
Pass
How many hydraulic systems are there - Answer- 4
How much pressure does each system provide? - Answer- 4000 psi
When is any hydraulic system pressurized - Answer- When any system pump is
operating
What powers the primary and secondary hydraulic pump - Answer- Engine driven
When does secondary hyd pump go active - Answer- When the primary pump px falls
below 3400
When is aux activated - Answer- When both primary and secondary pump px falls below
3400
Where is No 1/2 Aux pump located - Answer- Left wheel well
Where are 3/4 aux pump - Answer- Right wheel well
What does the Hyd Xfer Pump do? - Answer- Permits mechanical transfer of pressure
between no. 2/3 systems
What function does the Xfer pump mainly serve? Where is it located? - Answer-
Ensures ability to gear retract or raise cargo door/ramp if lose engine 2/3. In right wheel
pod
What hydraulic system incorporates the RAT? - Answer- 4
What is function if RAT - Answer- Pressurizes system 4, located in right gear pod,
develops pressure to control aircraft in 4 engine flameout
On ground, what systems does LM functions require - Answer- 2/3
What does HSC do? How many HSCs are there? - Answer- Monitor temps/quantity
Monitor pump temps/pressure
Selects pumps
2 HSCs
HYD RES TEMP X - Answer- Above 121C
, Hot light - Answer- Case drain temp above 135C
HYD QTY X LOW - Answer- Qty falls below 3.3/6.4/3.9/3.3 when at or above 27C or
1.2/3.3/1.2/1.2 below 27C
HSC INOP - Answer- One of 2 HSCs failed. No auto sequencing of engine driven pumls
RUD TEMP LOW - Answer- Hyd reservoir indicates rudder IFCM may be below -6C.
Fluid below temp where rudder effectiveness may be degraded
At what temps in hydraulic system should takeoff never be attempted - Answer- Below
7C bc may be insufficient rudder deflection in engine fail on TO
How can you control transfer pump if switch light failed - Answer- From aft LM panel
How many hydraulic systems power each primary flight control - Answer- 2
What would happen to primary flight controls if one of the associated sys failed -
Answer- Would still operate but at a slower rate
When will aux pump automatically shut down? - Answer- Low quantity (0.4) or high
temp (>135)
How would aux pump fail be indicated - Answer- Low px light
How can failure of engine driven pump be indicated? - Answer- Low pressure or hot
light
How should you handle hot light on the ground? What should you do if you get a hot
light in flight? - Answer- Cycle flight controls but in flight turn of system
How can you tell transfer pump has failed - Answer- abnormal pressure in system being
pressurized
If you suspect transfer pump fail what should you do - Answer- Turn off the pump
What will happen if low quantity in sys 2/3 - Answer- Affected aux pump + Xfer pump
shut off
How are aux pumps driven - Answer- Electrically via an AC motor
How are HSCs powered - Answer- 1- bat bus 2-Dc bus 3
What is the EDV for? How does it work? - Answer- Depressurizes pump. Blocks pump
outlet and commands min flow (1100 psi)
