Hydraulics

Question 1

When will RMPs be commanded on?

Answer 1

HSC to manual
ASE
Any N2<45% during taxi, TO, or landing
Both EDPs unable to maintain pressure during critical phase

Question 2

When will RMPs be commanded off?

Answer 2

Reservoir less than 1 gallon
ADG released in HYD mode (trying to retain sys 3 pressure for flight controls)
Not required for phase of flight

Question 3

RMP phase of flight logic

Answer 3

Requires 3 hyd systems if BLO FL180 and dirty. Clean or above FL180 requires 2 systems.

Question 4

What do the NRMPs power?

Answer 4

2-1 powers upper rudder and stab trim

3-2 powers lower rudder

Question 5

What is the purpose and operation of the Sioux City valve?

Answer 5

Valve will close with 4.75 gallons in sys 3. Shuts off fluid to the sys 3 elevators and 3-2 NRMP. Preserves fluid for stab trim and ailerons.

Question 6

When will HSC shut off EDPs?

Answer 6

Less than 2.5 gallons

Will not shut down if in critical phase (dirty below FL180)

Question 7

What does ADG power in HYD mode?

Answer 7

AUX pump 1, which will power HYD sys 3