TM 55-1520-240-T
8 - 1 . 4 P I T O T S T A T I C S Y S T E M O P E R A T I O N A L C H E C K ( C o n t i n u e d)
8 - 1 . 4
T A S K
R E S U LT
PITOT SYSTEM CHECK
12.
13.
14.
Do not apply vacuum to pitot
lines. Damage to airspeed indica-
tors can result.
At both AFCS computers disconnect and cap
off both pitot tube compression sleeve fittings.
Connect tester (13) to both pitot masts (4 and
Airspeed shall not decrease more than 10 knots in 5
5) and adjust
of 150 knots
off pressure.
pressure for an airspeed indication
minutes. If it does leak, go to task 8-1.13.
on tester airspeed indicator. Shut
NOTE
Airspeed must be corrected for tes-
ter leak rate. Refer to TM 55-4920-
231-14.
If PITOT system does not leak and
there is a log book entry indicating a
pitot leak, check AFCS computer in
suspected system and replace AFCS
computer.
Disconnect tester (13) from both pitot masts (4
and 5). Remove caps and connect compression
sleeve fittings to their respective AFCS com-
puters.
8-8
Change 4
