Turn And Bank Indicator; Troubleshooting - Piper Lance II Service Manual

Instrument malfunction.
LANCE II SERVICE MANUAL
10-58. REMOVAL AND REPLACEMENT. Refer to Paragraph 10-78 of this section.
10-59. TURN AND BANK INDICATOR.
10-60. GENERAL. The turn and bank indicator can be either vacuum driven or electric. The
turn portion of the indicator is a gyroscope, while the bank portion of the indicator is a ball
sealed in a curved glass tube filled with damping fluid. There are two styles of this unit, the
first is the old style with a vertical needle in the center of the dial. This instrument reads
only rate of turn, and unless the aircraft is turning, the needle will not move regardless of
bank angle. The other style is the turn coordinator which will also indicate rate of turn but
due to its construction will read rate of roll also, which means if the aircraft is rolled right
and left rapidly, the indicator will move, indicating a turn, but if the aircraft is held in a
bank, by applying rudder, the indicator will come back to zero indicating no turn.
10-61. TROUBLESHOOTING.
TABLE X-XII. TURN AND BANK INDICATOR
Trouble
Cause
Remedy
Pointer fails to
respond.
Incorrect sensitivity.
Incorrect turn rate
(vacuum style).
Foreign matter lodged in
instrument.
Out of calibration.
High or low vacuum.
Replace instrument.
Replace instrument.
Check vacuum and adjust.
Filter dirty.
Replace filter.
Incorrect turn rate
(electric)
(turn coordinator)
Ball sticky.
Ball not in center
when aircraft is
correctly trimmed.
Instrument will not
run (electric).
Out of calibration.
Aircraft not in
coordinated turn.
Flat spot on ball.
Instrument not level
in panel.
No power to instrument.
Replace instrument.
Center ball in turn.
Replace instrument.
Level instrument.
Check circuit and repair.
Replace instrument.
Isued: 1/3/78
INSTRUMENTS
2F3