TM 10-1670-300-20&P
TO 14D1-2-469-2
NAVAIR 13-1-42
2-14.
ALTIMETER
This task covers:
a.
Inspect
b.
Test
c.
Service
d.
Repair
e.
Replace
INITIAL SETUP
Tools:
Screwdriver, cross tip (Appendix B, Section III, Item 3)
Sewing machine, light duty
Shears
Materials/Parts:
Altimeter, parachutists
Battery, Nickel-Cadmium
Fastener tape, hook (Appendix D, Item 10)
Fastener tape, loop (Appendix D, Item 9)
Thread, Nylon
INSPECT
Inspect altimeter in accordance with Table 2-1 and paragraph 2-10
TEST
a.
Functional Test. Free-fall parachutist's pressure altimeter shall be tested every 90 days, or whenever accuracy
is doubtful.
(1)
Set the master altimeter in the vacuum test chamber at 29.92 inches.
(2)
Observe the indicated altitude on the master altimeter in the test chamber and set the test altimeter at the
same altitude.
(3)
Place the test altimeter in the test chamber in a manner that will allow test altimeter and master altimeter
to be observed simultaneously
(4)
Close the chamber and evacuate to an altitude of 30,000 feet. As the chamber is evacuated, check the
test altimeter against the master altimeter at indicated altitudes of 2500, 5000, 10,000, 15,000, and 30,000
feet When compared to the master altimeter the test altimeter should read within the tolerances for the
cited altitudes listed in Table 2-3. The altimeter shall remain at each altitude for not less than one minute
before the reading is taken.
NOTE
When reducing altitude m the test chamber, tap the master altimeter lightly with finger
tips frequently to prevent lag.
(5)
Stop the chamber at 30,000 feet and allow the test altimeter to be equilibrated. Reduce altitude at a rate of
180 to 250 feet per second and observe both altimeters.
2-27
