T-45A UJPT, E2-C2, ADV, & IUT Eng-09
Hydraulic System
SUMMARY
Sg 6, fr 1
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The T-45A has two hydraulic systems (HYD 1 and HYD
2) which operate independently of one another to power
the flight controls. Additionally, HYD 1 powers general
services. HYD 1 is the larger of the two and provides
hydraulic power to the flight controls (ailerons and
stabilator) and general services (flaps, slats, speed
brakes, NWS, landing gear/gear doors, wheel/parking
brakes, launch bar, arresting hook). HYD 2 supplies
hydraulic power to the flight controls and emergency
package assembly.
Both systems are powered by EDPs that produce a
constant output pressure of 3,000 psi. If either system
fails, the other system has enough hydraulic power to
operate the flight controls. Additionally, the emergency
hydraulic system acts as a backup to HYD 2 if the HYD 2
EDP is unable to maintain sufficient pressure. Because
the RAT is not designed to provide constant pressure
levels, control responses may be sluggish if only the RAT
is operating. If HYD 2 fails, HYD 1 will of course
maintain pressure to the flight controls and the general
services. However, if HYD 1 fails, HYD 2 is designed to
power only the flight controls. The general services will
rely on emergency backup systems, if available.
Because output pressure in both hydraulic systems is
continuously monitored, a malfunction in the hydraulic
system is relayed to the CWS, which then causes the
MSTR ALERT light to flash, sounds either the warning or
caution tone, and illuminates the appropriate warning/
caution lights on the WCP.
Cockpit controls and indicators include the HYD 1 and
HYD 2 pressure gauges, the BRAKE pressure gauge, the
brake pressure indicator lights, the HYD 2 RESET button,
and the following warning and caution lights on the WCP:
HYD 1 PRESS, HYD 2 PRESS, RAT EXTEND, and HYD
FAIL. Additionally, there are several indicators on the
exterior of the aircraft (the wheel brake/emergency flap
accumulator pressure gauge, HYD 1/HYD 2 FC
(8-03) Original
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