STUDENT GUIDE T-39N/G NATOPS
c. Aircraft ceiling is 45,000' MSL.
2. Dump valve prevents cabin pressure from exceeding 9.1 + .1 above outside pressure.
3. Cabin pressure dumps with weight on wheels.
4. AFT FUS HOT light if bleed air leak (135C).
-select RAM below 15K
-select EMER PRESS above 15K
5. CABIN AIR HOT light on if air downstream of mixing valve exceeds 130C - select MAN
NOTE: Expect this light if EMER PRESS is selected
6. Door seal will remain pressurized with dual gen fail (DC Essential power available); cabin
pressure will dump if TOTAL electrical failure.
7. Emergency pressurization from unconditioned RH bleed air; INOP ON DECK or if RH FIRE
handle pulled. Control air temperature with throttle position.
8. CABIN AIR SELECT switch controls bleed air valves
a. OFF - closes both shutoff valves.
b. BOTH ENG - Both bleed air shutoff valves open (normal position).
c. LH/RH ENG - single engine operations or contamination suspected.
d. RAM - closes both shutoff valves and opens ram air supply valve.
e. AM AND DUMP - same as RAM but dumps cabin pressure as well.
f. EMER PRESS - closes both shutoff valves and opens the emergency valve from RH
NOTE: In RAM or OFF, pressure will bleed off; RAM/DUMP = immediate depressurization.
9. CABIN TEMP switch/ AUTO CONTROL rheostat
a. OFF/AUTO/MAN HOT/MAN COLD (spring-loaded to OFF from MAN HOT or MAN
b. Rheostat only operative if BOTH or LH/RH ENG is selected on CABIN AIR SELECT
c. Auto temp range of 60-80F
10. CABIN PRESS FAIL red light if cabin altitude exceeds 10,000 + 400 feet. Will also get a
FASTEN SEAT BELT light.