T-45C TS, ADV & IUT ENG-27/ENG-28
Engineering Review
fixed displacement pump, emergency hydraulic
pressure will fluctuate between 2500 and 3000 psi
displayed on the HYD 2 gauge, whenever the RAT
is in operation
a.
Emergency hydraulic system components
(1) RAT
(a) Produces hydraulic pressure for
emergency hydraulic system in event
of HYD 2 EDP pressure loss
(b) Raised into airstream automatically
by hydraulic actuator when HYD 2
EDP pressure drops below 1500 psi
(c) Output volume and pressure vary
with pump speed (fixed displacement
pump)
(2) RAT accumulator
(a) Carries nitrogen preload and provides
hydraulic pressure to extend, and keep
fully extended, the RAT actuator when
HYD 2 EDP pressure drops below
1500 psi
(b) Regulator valve cycles pressure
between 2500 and 3000 psi, because
the RAT is a fixed displacement pump
whose output pressure is not internally
regulated
(c) Emergency package assembly
automatically deploys the RAT and
directs Emergency Hydraulic System
pressure to flight controls when HYD 2
pressure below 1500 psi
(9-98) Original
Page 27-55
Previous Page
