SECTION IV. SPECIAL PROCEDURES - TM-55-1510-218-MTF0123

TM 55-1510-218-MTF

SECTION IV. SPECIAL PROCEDURES

General. This section contains the special procedures

that were referenced in section II.

*A. Pressurization and Oxygen System. Check as

follows:

1. Bleed air valve switches (2) - OPEN.

2. After takeoff - Establish a climb.

3. Cabin altimeter - After takeoff the cabin altime-

ter needle should stabilize at selected altitude

250 feet and the cabin differential pressure

needle should continue climbing. The cabin al-

timeter 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.

a. Cabin pressurization leak rate - Check with-

in limits as follows:

b. Level off aircraft when pressure differential

reaches 60.1.

c. Bleed air valve switches (2) - ENVIRO OFF.

* 4. 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. Re-

establish 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 pres-

sure differential at 6.0+1. N1 should not exceed

85%. and the minimum desirable N1 is 80%.

8. Left bleed air valve switch - OPEN.

9. Right bleed air valve switch - ENVIRO OFF.

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