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

Page: 1460 / 1956

PAGE 2
Feb 28/07
7H14
77-20-00
PIPER AIRCRAFT, INC.
PA-46-350P, MALIBU MIRAGE
MAINTENANCE MANUAL
(5) Make sure that the adjustment screw, located at the rear of the instrument case, is in the
center of its travel. If this screw has been turned to either end of full travel, it will shut the
instrument off and no indication will be shown on the pointer. With the leads connected to
instrument, heat probe using an Alcor testing unit. The meter should read up to the fourth
graduation of approximately 1,500° F. If meter still does not read, replace it.
D. Gauge
(1) Removal
(a) Disconnect wires from the gauge at the instrument panel.
(b) Remove four screws which secure the gauge to the instrument panel and remove the
gauge.
(c) Remove wires from the wire harness going to the gauge.
(2) Installation
(a) Route the thermocouple wires along with the existing wire harness to the instrument
panel.
(b) Install the gauge into the instrument panel and secure it with four screws.
(c) Connect the thermocouple wires to the rear of the gauge.
F. Probe Replacement (See Figure 1.)
NOTE: The normal service life (limit) for the T.I.T. probe is two hundred-fifty hours time in service.
NOTE: If the probe time is unknown, initial replacement should occur within the next one hundred
hours time in service. If system inaccuracy is suspected, the probe should be replaced
immediately.
(1) Remove the engine cowling as required to expose the exhaust transition.
(2) Remove the existing T.I.T. probe mounted in a boss welded to the upper portion of the exhaust
transition.
(3) Install a new T.I.T. probe into the hole in the waste gate transition assembly and tighten.
(4) Run the aircraft and operationally check for a proper T.I.T. reading.
(5) Re-install the engine cowling.
G. System Calibration and Test
This procedure is applicable to the Lewis T.I.T. Indicators, either the standard analog P/N 471-008
or the optional digital P/N 548-811, and is required each time a T.I.T. Indicator is replaced or if
system error is suspected. It should be noted that T.I.T. probe replacement must occur at cylinder
changes, engine overhauls or should other T.I.T. system maladies become apparent.
EQUIPMENT REQUIRED: A variable D.C. millivolt power supply and a digital volt-ohm meter. If a
millivolt power supply is not available the following items will be required. One 5K Potentiometer
JS1N056S502UA (Allen-Bradley part number 481-239) or equivalent. One 27K OHM Resistor ±
10% 1/2 Watt. (See Figures 2 & 3.)
(1) Place the aircraft in an enclosed hanger where the temperature may be stabilized between 50
- 90° F. (Please take note that the successful completion of this calibration procedure is
dependent upon stabilizing the aircraft temperature prior to starting calibration.)
(2) Disconnect the leads of the existing T.I.T. probe which is mounted in a boss welded to the
exhaust transition. (See Figure 1.)