TM 55-1510-219-MTF
SECTION IV. SPECIAL PROCEDURES
GENERAL. This section contains the special procedures that were
referenced in section II.
*A. PRESSURIZATION SYSTEM.
Check as follows:
1.
Bleed air valve switches (2) - OPEN.
2.
After takeoff- Establish a climb.
3.
Cabin altimeter After takeoff the cabin altimeter needle should
stabilize at selected altitude ±
250 feet and the cabin
differential pressure needle should continue climbing. The
cabin altimeter needle should remain at selected altitude until
the maximum pressure differential of 6. 0±.1 is reached. At
this point (approximately 16, 600 feet pressure altitude) the
cabin altitude should increase while the differential pressure
remains constant.
4.
Cabin pressurization leak rate - Check within limits as follows:
a.
Level off aircraft when pressure differential reaches
6.0±1.
b.
Bleed air valve switches (2) - ENVIRO OFF.
c. Cabin rate-of-climb indicator Read and record cabin rate of
climb. Cabin rate of climb (cabin pressurization leak rate)
should not exceed 2200 feet per minute.
5.
Bleed air valve switches (2) - OPEN. Reestablish 6.0±.1 PSI
cabin pressure differential.
6.
Left bleed air valve switch - ENVIRO OFF.
7.
Slowly retard the right power lever and record the minimum
N1 speed that the right engine must be operated at to maintain
the cabin pressure differential at 6.0±.1. N1 should not exceed
85%, and the minimum desirable N1 is 80%.
8.
Left bleed air valve switch - OPEN.
4-1
