Endeavor CRJ900/700 SYSTEMS (workbook)
Hydraulics, Flight Controls, Landing Gear
How many hydraulic pumps exist on the CRJ 900? ✔️Ans - 6 pumps, 4
electric and 2 engine driven.
Arrange the hydraulic systems, in terms of size, from
largest to smallest. ✔️Ans - 3-2-1
Which components would you lose if you lost Hydraulic
System 1? ✔️Ans - Look at Hydraulic Synoptic Page
Which components would you lose if you lost Hydraulic
System 2? ✔️Ans - Look at Hydraulic Synoptic Page
Which components would you lose if you lost Hydraulic
System 3? ✔️Ans - Look at Hydraulic Synoptic Page
What would you be concerned about if you were to lose
Hydraulic System 2 & 3? ✔️Ans - Can't get the nose gear lowered
What effect on the braking system would be a loss of
Hydraulic system 3? ✔️Ans - 50% of your braking power is gone
How many brake applications would be possible following
system 2 & 3 failure? ✔️Ans - Up to 6 full applications
When will Hydraulic Pumps 1B & 2B turn on in the
"AUTO" position? ✔️Ans - Flaps moved out of 0 position (>= 8 selected)
When will Hydraulic Pumps 1B & 2B turn on in the "ON"
position? ✔️Ans - Cross-side AC bus
What is Hydraulic interlock? ✔️Ans - Removes the requirement of a
generator to be online, so the B pumps can
run on external AC for testing on the ground (don't care)
When will Hydraulic Pump 3B operate in the "AUTO"
, position? ✔️Ans - Flaps out of zero position (>= 8 selected)
What are the normal system pressures and quantity? ✔️Ans - 3000 PSI and
Green range (45% - 85%)
What temperature will solicit a HYD 1(2) HI TEMP
message? ✔️Ans - 96°C
When will Hydraulic Pump 3B operate regardless of switch
position? ✔️Ans - ADG Deployment (Emergency Power Only)
The aircraft is flying normally in cruise at FL 290, the right
engine flames out and cannot be re-started. What are all of
the hydraulic implications? Would you receive a HYD 2
LO PRESS message? ✔️Ans - Yes (Cruise = flaps up). Lost primary pump for
HYD 2. Checklist would lead to turning the 2B to the On position to
repressurize HYD 2
True / False, Hydraulic 1B, 2B, 3B, will turn on
automatically following a low pressure condition in their
respective system: ✔️Ans - False
You are following the HYD 1 LO PRESS checklist when
you receive a HYD 2 LO PRESS caution message, what will
you do? ✔️Ans - Stop and go to the Dual Failure checklist
After an engine failure, the checklist directs you to turn the
associated "B" pump to the "ON" position, why? ✔️Ans - Auto doesn't look
for low pressure
Which hydraulic systems power the primary flight
controls? ✔️Ans - All three systems.
Which hydraulic system powers the inboard multi-function
spoiler panels, and how many PCUs exist per panel? ✔️Ans - System 2. One
PCU per panel
Which hydraulic system powers the slats / flaps? ✔️Ans - None.
Slats/Flaps are electrically powered and actuated.
Hydraulics, Flight Controls, Landing Gear
How many hydraulic pumps exist on the CRJ 900? ✔️Ans - 6 pumps, 4
electric and 2 engine driven.
Arrange the hydraulic systems, in terms of size, from
largest to smallest. ✔️Ans - 3-2-1
Which components would you lose if you lost Hydraulic
System 1? ✔️Ans - Look at Hydraulic Synoptic Page
Which components would you lose if you lost Hydraulic
System 2? ✔️Ans - Look at Hydraulic Synoptic Page
Which components would you lose if you lost Hydraulic
System 3? ✔️Ans - Look at Hydraulic Synoptic Page
What would you be concerned about if you were to lose
Hydraulic System 2 & 3? ✔️Ans - Can't get the nose gear lowered
What effect on the braking system would be a loss of
Hydraulic system 3? ✔️Ans - 50% of your braking power is gone
How many brake applications would be possible following
system 2 & 3 failure? ✔️Ans - Up to 6 full applications
When will Hydraulic Pumps 1B & 2B turn on in the
"AUTO" position? ✔️Ans - Flaps moved out of 0 position (>= 8 selected)
When will Hydraulic Pumps 1B & 2B turn on in the "ON"
position? ✔️Ans - Cross-side AC bus
What is Hydraulic interlock? ✔️Ans - Removes the requirement of a
generator to be online, so the B pumps can
run on external AC for testing on the ground (don't care)
When will Hydraulic Pump 3B operate in the "AUTO"
, position? ✔️Ans - Flaps out of zero position (>= 8 selected)
What are the normal system pressures and quantity? ✔️Ans - 3000 PSI and
Green range (45% - 85%)
What temperature will solicit a HYD 1(2) HI TEMP
message? ✔️Ans - 96°C
When will Hydraulic Pump 3B operate regardless of switch
position? ✔️Ans - ADG Deployment (Emergency Power Only)
The aircraft is flying normally in cruise at FL 290, the right
engine flames out and cannot be re-started. What are all of
the hydraulic implications? Would you receive a HYD 2
LO PRESS message? ✔️Ans - Yes (Cruise = flaps up). Lost primary pump for
HYD 2. Checklist would lead to turning the 2B to the On position to
repressurize HYD 2
True / False, Hydraulic 1B, 2B, 3B, will turn on
automatically following a low pressure condition in their
respective system: ✔️Ans - False
You are following the HYD 1 LO PRESS checklist when
you receive a HYD 2 LO PRESS caution message, what will
you do? ✔️Ans - Stop and go to the Dual Failure checklist
After an engine failure, the checklist directs you to turn the
associated "B" pump to the "ON" position, why? ✔️Ans - Auto doesn't look
for low pressure
Which hydraulic systems power the primary flight
controls? ✔️Ans - All three systems.
Which hydraulic system powers the inboard multi-function
spoiler panels, and how many PCUs exist per panel? ✔️Ans - System 2. One
PCU per panel
Which hydraulic system powers the slats / flaps? ✔️Ans - None.
Slats/Flaps are electrically powered and actuated.
