Piper Aircraft Corporation Malibu Mirage PA-46-350P, Airplane Maintenance Manual

Page: 1519 / 1956

PAGE 5
Feb 28/07 7K1
80-10-00
PIPER AIRCRAFT, INC.
PA-46-350P, MALIBU MIRAGE
MAINTENANCE MANUAL
E. Cranking Tests
WARNING: FAILURE TO CONSULT APPLICABLE VENDOR PUBLICATION(S), WHEN
SERVICING OR INSPECTING VENDOR EQUIPMENT INSTALLED IN PIPER
AIRCRAFT, MAY RENDER THE AIRCRAFT UNAIRWORTHY. (SEE INTRODUCTION
- SUPPLEMENTARY PUBLICATIONS.)
NOTE: NEVER USE JUMPER CABLES to test voltage to the starter. The "toothed" jaws of jumper
cables are meant to "bite" into soft, leaded terminals on car batteries, and simply WILL
NOT provide enough contact with the starter terminal to supply the needed amperage to
engage the starter properly.
NOTE: Use an analog voltage meter if you can. Digital meters take intermittent 'snap shots' of
voltage. In situations where voltage is being supplied intermittently (even in rapid cycles),
the digital meter will simply not provide the correct 'picture' of the aircraft's voltage
situation.
The starting circuit should be inspected at regular intervals. The frequency should be determined by
the type of starting conditions and the amount of starter usage. In any case, it is recommended that
the following tests be conducted each six months or every 100 hours time-in-service.
(1) Check the battery with a hydrometer to make sure it is fully charged and filled to the proper
level. A load test should be made on the battery to verify proper condition before proceeding.
(2) Check all starter circuit wiring, making sure all connections, including battery terminals, are
clean and tight and that all insulation is sound and complete.
(3) A voltage loss test should be made to locate any high-resistance connections that would impair
starting motor electrical efficiency. Using a low-reading voltmeter scale while cranking engine
(or at approximately 100 amperes current flow) measure for the following limits:
(a) Voltage loss from the insulated (positive) battery post to the starter motor terminal = 0.3
volt maximum.
(b) Voltage loss from the battery negative (ground) terminal to the starter motor frame = 0.1
volt maximum.
NOTE: If voltage loss exceeds the above limits, measure the voltage drops across all
connections to discover the faulty connection. When within the maximum limits
proceed to next step.
(4) The starter motor should be operated for several seconds with the ignition OFF. The starter
motor engagement should be prompt and the motor should turn freely at a uniform speed
without binding or producing unusual sounds.
(5) Re-engage the starter two or three times, listening for prompt engagement, without the
clashing of gears, and to determine that the pinion disengages properly when the starter
switch is released.