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

Page: 574 / 1956

PAGE 12
Feb 28/07
3E6
27-30-00
PIPER AIRCRAFT, INC.
PA-46-350P, MALIBU MIRAGE
MAINTENANCE MANUAL
5. Stall Warning System
A. Description and Operation
WARNING: PHYSICAL MANIPULATION OF LIFT TRANSDUCER ON PA-46-350P AIRPLANES
MAY RESULT IN ERRONEOUS STALL WARNINGS NECESSITATING CALIBRATION
OF SYSTEM.
The stall warning system’s major components consist of a lift transducer located in the leading edge
of the left wing, the sensing source of the transducer protrudes into the air stream and during flight
is positioned by local airflow velocity and direction. By correlating lift with airflow characteristics at
the stagnation point on the wing, the lift transducer measures changes in angle-of-attack, or
airspeed deviations from an airspeed represented by a reference angle-of-attack.
The output signal, combining angle-of-attack and local dynamic pressure, enters the lift computer
which contains power regulators, signal processor and control circuitry. Provisions are included for
monitoring the entire stall warning system.
B. Lift Detector Assembly
(1) Removal
(a) Remove the four screws which hold lift detector to leading edge of wing.
(b) Pull lift detector partially out of opening in wing and disconnect wires at connector.
(c) Remove lift detector.
(2) Installation
(a) Connect wires from detector to harness.
(b) Position lift detector in the opening in the wing and secure with the four screws.
(c) Check lift detector for operation per Stall Warning Functional Test.
C. Dual Warning Unit (Horn)
(1) Removal
(a) Disconnect wires coming from warning unit.
(b) Remove the four screws and washers that secure the unit to the bulkhead.
(2) Installation
(a) Position dual warning unit on the bulkhead and secure with screws/washers.
(b) Connect electrical leads to unit (refer to electrical schematic in 91-27-30).
D. Stall Warning Functional Test
(PIR-PPS-60089-2, Rev. E)
(1) Locate the stall warning test switch on the pilot’s instrument panel and the lift transducer which
is located in the inboard left wing leading edge.
(a) Activate the test switch.
(b) Verify that the transducer vane moves forward (up); the stall warning activates.
(2) Locate the stall warn heat switch on the center instrument panel (if installed).
CAUTION: DO NOT ACTIVATE STALL WARN HEAT SWITCH FOR MORE THAN FIVE (5)
SECONDS.
(a) Depress left main gear uplock switch.
(b) Activate the stall warn heat switch.
(c) Check that the lift transducer vane and mounting plate become warm.