TM 55-1520-240-23-7
8-35
TEST AIRSPEED INDICATOR RESTRICTOR
(Continued)
8-35
3.
Connect hose (5) of tester (6) to tee (3).
4.
Connect external case leak valve (7) to tee (3).
Make sure valve is closed.
NOTE
External case leak valve is part of
tester.
5.
Check that indicator (2) reads 0.
6.
Adjust tester (6) until indicator (2) reads 250
knots (TM 55-4920-231-14).
7.
Close external case leak valve (8). Check that
indicator (2) reading does not change.
8.
Open valve (7) and record time for indicator (2)
reading to drop to 20 knots. Use stopwatch.
Elapsed time shall be 3.5 to 4.0 seconds.
9.
Open valve (8) and close valve (7).
10.
Repeat steps 5 thru 8 twice. Adjust restrictor if
recorded times are not 3.5 to 4.5 seconds (Task
8-37).
11.
Disconnect hose (5) from tee (3).
12.
Shut down tester (6) (TM 55-4920-231-14).
13.
Remove valve (7), tee (3), and coupling (4) from
restrictor (1).
14.
Remove restrictor (1) from airspeed indicator (2).
FOLLOW-ON MAINTENANCE:
None
END OF TASK
8-117
