T-45A UJPT, E2-C2, ADV, & IUT Eng-17
ECS/Pressurization System & OBOGS
C.
Oxygen monitor (fwd cockpit only): continuously
Sg 7, fr 4 (1 overlay)
samples oxygen-enriched air for proper
concentration level
D.
OBOGS BIT
1.
OBOGS pneumatic BIT button, when
pressed and held, activates BIT operation;
releasing the button deactivates BIT circuit
OXYGEN MONITOR
a.
Oxygen warning light illuminates within
65 seconds holding test button down
b.
Oxygen warning must go out within
60 seconds after releasing test button
c.
Test is performed at idle RPM
NOTE: Do not rotate the SSOM pneumatic
BIT button during actuation to prevent
engagement of the locking slot.
2.
OBOGS BIT on the solid-state oxygen
monitor (SSOM)
a.
Power-up BIT: conducted when
electrical power is initially applied to
verify SSOM operability and to warm
Overlay 1
SSOM Electrical Bit Button
up the oxygen sensor
b.
Periodic BIT: automatically performed
every minute during both normal
operation and after a fault is detected
c.
Electrical BIT: used by maintenance
personnel to manually initiate a BIT,
equivalent of periodic BIT
Warning: Testing the OBOGS above 9,000 ft
MSL shuts down the OBOGS.
(8-03) Original
Page 17-19
Previous Page
