HYDRAULICS Flashcards
L HYD SYSTEM PRESS lights ON
How can you tell the PTU is working?
pressure transmiter for the SYS PRESS light is upstream of the pressure transmiter for the EICAS hyd indication
normal PTU output cannot extinguish SYS PRESS
EICAS must be checked to confirm PTU operation
RAT UNLKD means?
RAT is NOT stowed and locked
What is RAT?
Ram Air Turbine
the RAT supply power to what system?
Center Hydraulic system
When does the RAT activate?
Air/ground switch in air mode and
AIS>80Kts and
Both engine fails
At what speed does the RAT operate?
above 130Kts
What are the source of power of the RAT? auto and manual?
BAT Bus power auto RAT deployement
HOT BAT BUS power manual RAT deployement
What does the PTU do?
Hyd motor pump
transfer hyd power from Right to Left
When is the PTU automatically activated? (2)
L eng fails (N2/N3<45%) or
L eng pump pressure low
What does the PTU powers?
Flaps and Slats
LG
NWS
HDG
if Right eng is not operating, PTU?
PTU is not working
POWER XFER UNIT message when? (3)
PTU is NOT producing press when demanded
PTU is producing press when NOT demanded
PTU is producing press when R eng is NOT running
What supply power to the HDG?
L HYD System
When does the HDG automatically activates?
When both L and R main AC BUS are unpowered
What does the HDG power? (6)
AC L/R TRANSFER BUS AC STANDBY BUS AC CAPTAIN FLIGHT INSTR TRANSFER BUS (FO on EK) DC BAT BUS DC HOT BAT BUS DC STANDBY BUS
