Hydraulics Flashcards
Accumulators provide enough pressure for a minimum of
Seven full brake applications
If green system hydraulic pressure fails, the blue system automatically takes over and powers the brakes. Antiskid remains
Available and nosewheel steering is lost.
When the antiskid and nosewheel steering switch is OFF, the
Blue hydraulic system powers the brakes. Antiskid is deactivated.
The bottom arcs of the triple indicator shows
Blue hydraulic system pressure delivered to the brakes on each side measured upstream of
Autobrake armed, blue ON. Autobrake activated DECEL
In green
When temperature of any brake exceeds
300ºC it is displayed solid amber. The arc above the hottest wheel becomes solid amber.
Tire pressure indicating system
TPIS
With parking brake on – crew is able to check
Brake wear indicators during exterior inspection
If during an engine start with the PARK BRK ON, aircraft begins to move due to a parking brake failure, immediately
Release the PARK BRK handle to restore braking via the pedals.
Safety exterior inspection, check condition of wheels and tires,
Hydraulic lines, brakes and brake wear indications
Preliminary – check – PRK BRK on, gear lever down,
Accumulator and brake pressure
Before pushback or engine start, check the
Memo display for N/WS DISC green
After landing, autobrake should be disengaged prior to reaching
20 kt,
Land gear down locked – extra fuel consumption
2.8
If there is a problem with landing gear not up – locking, maintain speed no greater than
250kt
LDN gear down, fuel consumption increases. Multiply it by
2.8 and disregard flight management computer fuel predictions.
To extend LDG gear, reduce to
200kt, first, then extend. LDG gear by gravity extension
Hydraulic three areas:
System overview, generation systems, distribution systems
Hydraulic pressure
3,000 psi (+ - 200psi); RAT 2,500psi
Hydraulic system monitoring units controls
3 systems
Note: yellow electrical pump does not operate if
Green is operating landing gear
Green system electric pump can be controlled
Manually or automatically
Normal system operating pressure is
3,000psi and RAT 2,500psi
Engine hydraulic pump 1 or 2 fault light illuminates amber if
reservoir low air pressure and or low level.
In the event of engine failure, green system electric pump runs for
25 seconds when landing selector lever is selected up and aircraft speed is above 100 kt
In AUTO mode, HSMU automatically controls
Hydraulic pumps.
In the event of a failure of engine 2, with flaps not at 0, yellow electric pump
remains running until the last engine shutdown
When leak measurement valves pb are OFF,
Primary flight controls are affected
RAT may be extended automatically in flight if
Both engines fail, GREEN and BLUE hydraulic reservoirs indicate low level or GREEN and YELLOW hydraulic reservoir indicate low level
When one of the three electric pumps in running HYD ELEC PUMP appears
In green on the memo display
Before raising a guarded button
Confirm the selection with PF and then raise the guard
The RAT has been deployed on ground and maintenance must be called to
Re stow the RAT
Yellow electrical hydraulic pump runs automatically if
Engine 2 fails in flight and flap lever is not at 0
