Troubleshooting Vertical Speed Indicator - Piper CHEROKEE WARRIOR PA-28-151 1995 Maintenance Manual

PIPER CHEROKEE WARRIOR SERVICE MANUAL
10-29. VERTICAL SPEED INDICATOR.
10-30. GENERAL.
The vertical speed indicator measures r a t e of change in static pressure when the airplane is e s t a blished
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 i n s t r ument will continue to indicate a climb or descent after the airplane is level. Thus, the instrument is
u n r eliable in rough air. This lag is not considered a malfunction.
10-31. TROUBLESHOOTING
If any connections in static system are opened for mainten a n c e ,
the complete system must be rechecked per F.A.R. 23.1325.
TABLE X-IV. TROUBLESHOOTING VERTICAL SPEED INDICATOR
TROUBLE
Pointer does not set on zero
when airplane is in accelerated
level flight.
Pointer fails to respond.
Pointer oscillates.
Vertical Speed reads when
a i rplane is banked.
Pointer has to be set before each
flight.
Pointer cannot be reset to zero
Revised: February 28, 1995
NOTE
CAUSE
Aging of diaphragm.
Obstruction in static line.
Static vents frozen over.
Water in static line.
Obstruction in pitot head.
Leaks in static lines.
Defective mechanism.
Water in static line.
Temperature compensator
i n o perative
Diaphragm distorted.
2C7
Island Enterprises
REMEDY
Use set screw to reset pointer on
zero. Tap instrument g e n t l y
while resetting.
Disconnect all instruments con-
nected to static line.Clear line.
Check individual instrument for
obstruction in lines.
Clean lines and head.
Disconnect all instruments
c o nnected to static line. Check
individual instruments for leaks.
Connect instruments to static
line and test installation for
leaks.
Replace instrument.
Disconnect static lines and blow
out lines from cockpit out to
pitot head.
Replace instrument
Replace instrument
INSTRUMENTS