B787 hydarulic system-operation sequence

[forevermyth]

hello, bros.
I'm a pilot just transit to B787.
I have a question for the operation of hydraulic system.
The question is similar to the a B777 HYDRAULIC SYSTEM,
B777 Hydraulic System [Archive] - PPRuNe Forums (http://www.pprune.org/archive/index.php/t-533649.html)

For 787. In FCOM NP, to pressurize hydraulic systems before engine start ( and to depressurize after engine shutdown) is still has a sequence to operate the hydraulic pumps.

SOP describe the sequence like this :

Before Start Procedure
HYDRAULIC panel....................................................... . Set F/O
WARNING: If the tow bar is connected, do not pressurize the hydraulic systems until the nose gear steering is locked out. Unwanted tow bar movement can occur.
RIGHT ELECTRIC DEMAND pump selector ..................AUTO
Verify that FAULT light is extinguished.
CENTER 1 and CENTER 2 ELECTRIC pump selectors .. AUTO
Verify that the FAULT lights are extinguished.
LEFT ELECTRIC DEMAND pump selector .................... AUTO
Verify that the FAULT light is extinguished.

Shutdown Procedure
HYDRAULIC panel ........................................................Set F/O
LEFT ELECTRIC DEMAND pump selector ........................ OFF
CENTER 1 and CENTER 2 ELECTRIC pump selectors ...... OFF
RIGHT ELECTRIC DEMAND pump selector ..................... OFF

I don't know what the sequence use for? just like the B777, to prevent fluid transfer between systems?

B787 uses the electrical brake system ,so it doesn't need hydraulic, right?


I hope I can get a certain answer, it's better let me know it has a record from some materials.

BEST WISHES FOR YOU.

[eckhard]

I think the 787 has kept as many procedures as possible the same as the 777 to comply with the 'common type rating' philosophy.

A training captain told me that the Hydraulic Pump switching that you describe is not strictly necessary on the 787 but it is important on the 777. Boeing has kept the same procedure to avoid confusion.

[Manual Reversion]

There's no connection between hydraulic systems. It's purely for 777 commonality