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

Page: 1466 / 1956

PAGE 8
Feb 28/07
7H20
77-20-00
PIPER AIRCRAFT, INC.
PA-46-350P, MALIBU MIRAGE
MAINTENANCE MANUAL
4. Cylinder Head Temperature Indicator Calibration Check
(PIR-PPS60182, Rev. A.)
( S/N’s 4636021 thru 4636374. )
All equipment necessary for the proper operation of the CHT, including the CHT/VAC Dual Analog
Module Indicator, the cylinder head temperature scanner, and all six CHT probes with proper harnesses,
must be installed in the aircraft and be operational prior to the test, adjustment, and validation described
below.
A. Testing
(1) Remove CHT probe from #1 cylinder.
(2) Disconnect harness from probe for #1 cylinder.
(3) Connect test box (see Figure 4, construct locally if required) to the two leads removed from
probe for #1 cylinder.
(4) Turn switch on test box to 100° F and turn on aircraft power. The CHT indicator should read
100° F ± 10° F. Record displayed value.
NOTE: Engine temperature must be less than 100° F. If temperature is higher than 100° F,
press CHT scanner cycle switch repeatedly until lamp for #1 cylinder on instrument
panel is illuminated. Hold switch in until temperature is displayed on Quad Digital
Indicator (QDI) / Enhanced Digital Indicator (EDI) (see 77-40-00).
(5) Turn switch on test box to 450° F. The CHT indicator should read 450° F ± 10° F. Record
displayed value.
NOTE: CHT scanner must be operating during these tests.
(6) If the CHT indicator meets the specified limits, go to Securing the System, below. If the CHT
indicator does not meet the specified limits, proceed to Adjustment or Validation, below,
depending on aircraft serial number.
B. Adjustment (P/N 599-588 only - original equipment in S/N’s 4636021 thru 4636131 only. )
NOTE: P/N’s 602-299 or 602-247, installed as original equipment in S/N’s 4636132 thru 4636374
are backward compatible and may be encountered in S/N’s 4636021 thru 4636131 as
service spares. They can be identified by the lack of potentiometers and are not adjustable.
If encountered, validate per paragraph C, below.
(1) With test box connected per Testing steps (1) - (3), above, select 100° F on test box. Remove
CHT/VAC dual analog module indicator from the instrument panel far enough to remove foil
sticker from the side of the CHT indicator. Adjust (z) zero potentiometer so that the QDI
displays 100° F.
(2) Select 450° F on test box. Adjust (s) span potentiometer so that the QDI displays 450° F.
(3) Return test box switch to 100° F setting and check that CHT indicator reads 100° F ± 10° F. If it
does not, readjust the (z) zero potentiometer.
(4) Set switch on test box to 450° F setting and check that CHT indicator reads 450° F ± 10° F. If it
does not, readjust the (s) span potentiometer.
(5) Repeat steps (3) and (4) until no adjustment is required to repeat 100° F and 450° F readings
when the test box is set to the corresponding switch position.