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

Page: 596 / 1956

PAGE 4
Feb 28/07
3F4
27-60-00
PIPER AIRCRAFT, INC.
PA-46-350P, MALIBU MIRAGE
MAINTENANCE MANUAL
5. Asymmetric Logic Switching
The Asymmetric Logic Switching Unit (which is located under the rear co-pilot floor closeout) monitors
SpeedBrake Cartridge position and will cut power to both SpeedBrake Cartridge clutches causing
instant blade retraction. This happens for two conditions:
A. Both SpeedBrake Cartridge fails to extend completely within four (4) seconds, or
B. One SpeedBrake Cartridge is contacted after extension (birdstrike, large hail etc).
NOTE: The gearmotors will continue to run after clutch power has been disconnected, with the
SpeedBrake switch in the ON position.
6. SpeedBrake Switch
The control yoke-mounted SpeedBrake Switch controls SpeedBrake extension and retraction.
7. SpeedBrake Annunciator
The SpeedBrake Annunciator is mounted (separately) on the instrument panel above the pilot’s airspeed
indicator. It illuminates after both SpeedBrakes are extended and extinguishes after both SpeedBrakes
are stowed.
8. Testing
A. Basic Functional Test
A properly operating SpeedBrake system should function as specified below:
(1) Turn on aircraft power.
(2) Switch SpeedBrakes ON. Full deployment should occur in no more than 2.5 seconds.
WARNING: DO NOT PUT FINGERS IN HOLES OF EXTENDED SPEEDBRAKE BLADES. IF
POWER TO THE SYSTEM IS INTERRUPTED, THE SPEEDBRAKE BLADES
WILL CLOSE WITH SUFFICIENT FORCE TO AMPUTATE FINGERS.
(3) Verify motor stop. Verify full blade extension. Proper blade position is 87° ± 2°.
CAUTION: DO NOT PUSH SPEEDBRAKE BLADES DOWN, IF THEY FAIL TO RETRACT.
FORCING SPEEDBRAKE BLADES DOWN WILL DAMAGE THE UNIT.
(4) Switch SpeedBrakes OFF. Full retraction should occur in no more than 2.0 seconds.
(5) Verify motor stop. Verify full blade retraction. Proper blade position is 0° ± 2°.
(6) Repeat steps (2) thru (5) several times to verify proper operation.
(7) Turn off aircraft power.
B. Speedbrake Cartridge Tester
Precise Flight offers a speedbrake cartridge test connector which is used to conduct a more precise
functional test. The cartridge test connector is available from your Piper Distributor as P/N 762-138
and is used as follows:
(1) Turn aircraft power OFF.
(2) Remove left speedbrake access panel.
(3) Disconnect left speedbrake cartridge from wiring harness.
(4) Connect the cartridge test connector to the left speedbrake wiring harness.