TROUBLESHOOTING GUIDE B - INSTRUMENTS - TM-55-1510-218-MTF0090

TM 55-1510-218-MTF

TROUBLESHOOTING GUIDE B - INSTRU-

MENTS

CONDITION

PBOBABLE CAUSE

Airspeed indicator reading remains fixed.

B1.

a. Pitot pressure line clogged with ice or debris.

Vertical velocity indicator inaccurate or inopera-

B2.

tive.

a. Static line clogged.

b. Leak in line or instrument case or loose fit-

tings.

c. Defective vertical velocity indicator.

Airspeed indicator reads incorrectly or fluctuates

B3.

excessively.

a. Pitot tube or pressure line partially restrict-

ed or leaking.

b. Static port or line clogged or static line leak-

ing.

c. Faulty airspeed indicator.

B4.

Magnetic compass inaccurate, sluggish or errat-

ic.

a. Insufficient liquid.

b. External magnetic interference.

c. Defective compass.

d. Windshield heat on.

Turn-and-slip indicator inoperative or erratic.

B5.

a. Tripped turn-and-slip circuit breaker.

b. Defective turn-and-slip instrument.

B6.

Fuel quantity indicator fluctuates or reads low.

a. Defective pins in connector on harness that

mates with gage.

3-4