Piper PA-28-161, Maintenance Manual

Page: 388 / 1104

PIPER AIRCRAFT, INC.
PA-28-161, WARRIOR III
MAINTENANCE MANUAL
PAGE 14
Nov 30/06
2I14
27-30-00
5. Stall Warning
The stall warning system consists of a lift detector electrically connected to a stall warning horn. As
stalling conditions are approached, the lift detector activates the stall warning horn.
The lift detector is on the leading edge of the left wing. A tab will extend beyond the leading edge at the
point where lift detector is mounted. With the master switch in the ON position, gently lift the tab; the stall
warning horn should sound.
The electrical circuit is protected by a 5 amp STALL WARNING circuit breaker mounted in the circuit
breaker panel on the lower right side of the instrument panel.
A. Removal
CAUTION: MASTER SWITCH MUST BE OFF BEFORE WORKING ON LIFT DETECTOR OR
WARNING HORN. WHEN INSTALLING WING, PLACE REFERENCE MARKS ON
HOLDING PLATE AND WING SKIN.
(1) Remove four screws holding plate around tab. Lift detector is fastened to the plate; remove unit
from wing.
(2) Mark electrical wires and terminals to aid installation. Remove electrical wires from lift detector;
remove lift detector from airplane.
B. Installation
NOTE: Refer to Chapter 91 for electrical schematic of stall warning system
(1) Attach electrical wires to their correct terminals on lift detector.
(2) Position lift detector with its mounting plate on wing, so sensor blade drops down freely; secure
in position with the four screws previously removed.
C. Adjustment
The lift detector switch is adjusted at the factory when the airplane is test flown, and should not
require further adjustment during normal service life of the airplane. If service on the wing requires
removing the switch, the following instructions will aid in proper switch positioning.
CAUTION: NEVER ADJUST SWITCH BY BENDING VANE.
(1) Loosen the two Phillips head screws; one on either side of vane. If stall warning sounds too
late, move switch up. If stall warning sounds too early, move switch down. Tighten screws after
adjustments.
(2) The only way to test accuracy of the setting is to fly the airplane into a full stall condition and
note speed at which the stall warning sounds. Stalls must be made with flaps up and power off.
It may be necessary to make several test flights and alternate adjustments before the desired
setting is obtained. The stall warning must sound not less than five mph, or more than ten mph
before the stall occurs.