TROUBLESHOOTING GUIDE B - INSTRUMENTS

TM 1-1510-223-MTF

A7. Engine fails to or is slow to accelerate propeller to

idle. speed.

a. Propeller oil transfer sleeve binding.

TROUBLESHOOTING GUIDE B - INSTRUMENTS

CONDITION

PROBABLE CAUSE

B1.

Airspeed indicator reading remains fixed.

a. Pitot pressure line clogged with ice or debris.

b. Defective indicator.

B2.

Vertical speed

indicator

inaccurate

inoperative.

a. Static line clogged.

b. Leak in line or instrument case or loose fittings.

c. Defective vertical velocity indicator.

B3.

Airspeed indicator reads

incorrectly

fluctuates excessively.

a. Pitot tube or pressure line partially restricted or

leaking.

b. Static port or line clogged or static line leaking.

c. Faulty airspeed indicator.

B4.

Magnetic compass inaccurate, sluggish, or

erratic.

a. Insufficient liquid.

b. External magnetic interference.

c. Defective compass.

d. Windshield heat on.

e. Air conditioner on.

f. Sun visors not stowed outboard.

g. EFIS power switches on.

B5.

Turn-and-slip indicator inoperative or erratic.

a. No pneumatic pressure.

b. Defective turn-and-slip instrument.

3-3