PIPER AIRCRAFT, INC.
PA-28-161, WARRIOR III
MAINTENANCE MANUAL
PAGE 3
Nov 30/06
3G11
34-10-00
2. V
ertical Speed Indicator
A. Description and Operation
The vertical speed indicator measures rate of change in static pressure when the airplane is
established in a climb or descent. A pointer and dial will show the airplane’s rate of climb or descent
in feet per minute. Due to instrument lag, the airplane will be climbing or descending before the
instrument starts to indicate. The instrument will continue to indicate a climb or descent after the
airplane is level. Thus, the instrument is unreliable in rough air. This lag is not considered a
malfunction.
B. Troubleshooting
See Chart 1.
NOTE
: If any connections in static system are opened for maintenance, the complete system must
be rechecked per F.A.R. 23.1325.
CHART 1
TROUBLESHOOTING VERTICAL SPEED INDICATOR
Trouble Cause Remedy
Pointer does not set on zero Aging of diaphragm. Use set screw to reset
when airplane is in accelerated pointer on zero. Tap
level flight. instrument gently while
resetting.
Pointer fails to respond. Obstruction in static line. Disconnect all instruments
connected to static line.
Clear line.
Static vents frozen over.
Check individual instrument
Water in static line. for obstruction in lines.
Obstruction in pitot head. Clean lines and head.
Pointer oscillates. Leaks in static lines. Disconnect all instruments
connected to static line.
Check individual instruments
for leaks. Connect
instruments to static line and
test installation for leaks.
Defective mechanism. Replace instrument.
Vertical Speed reads when Water in static line. Disconnect static lines and
airplane is banked. blow out lines from cockpit
out to pitot head.
Pointer has to be set before Temperature compensator Replace instrument.
each flight. inoperative.
Pointer cannot be reset to zero. Diaphragm distorted. Replace instrument.
Instrument reads much less Instrument case broken Replace instrument.
than actual rate during or leaking.
climb or descent.
To Next Page
Loading...
