Hydraulics Flashcards
How is hydraulic quantity displayed on the status display?
In percentages (1.0 is full)
How many hydraulic systems are there ?
3
How can you tell if hydraulic needs refilling ?
Numbers turn amber on status & RSVR light on overhead panel illuminates
What does RSVR light on hydraulic overhead panel mean?
Low quantity or pressure
Does the 757 have demand pumps (hydraulic)?
No only 767
What does the air driven hydraulic pump on the 767 supplement ?
Gear and flaps hydraulics
When do command pumps come on?
When primary pump pressures are low - center ADP - when high load items selected (gear & flaps)
What does the reserve brakes & steering do on the 767?
Isolates the center #1 electric pump to provide hydraulic press to the reserve brakes & steering system if system quantity is low
Whats the main difference between 757 200 & 757 ER HYDRAULIC system?
ER has HDG
What hydraulic system is the HDG on (757 ER). How does the HDG work if you lose that hydraulic system?
1. PTU supplies HDG through system 3 if #1 fails
What system is the HDG on in the 767 ? What comes on automatically if HDG comes on?
Center - ADP operates continuously if HDG operating
Which demand pump is inhibited during engine start on the ground (767)
Left
How is the hydraulic reservoir pressurized?
Bleed air system
What does RF display on the status page mean?
Hydraulic reservoir needs refilling
What does pulling the fire switch do to the hydraulic system?
Shuts off fluid to the engine driven pump & depressurizes the pump
What is the critical system on the 767? 757?
What are some of the important items?
767- CENTER
757 - LEFT
Nose wheel steering, alt brakes, landing gear, HDG.
What is the reserve hydraulic fluid used for on the 757?
For use of the PTU in case of LEFT system hydraulic leak
What does the PTU do on the 757 - when does it activate?
When is PTU inhibited?
Transfers power from the RIGHT to LEFT system if L engine fails or L engine driven pump pressure is low (supplements L elec motor pump)
PTU is inhibited if right engine not operating
When does the RAT automatically deploy?
What does it power?
RAT deploys automatically when both engines fail.
It powers the flight control portion of the center hydraulic system
