(b)
Ensure lift transducervane, located in leading edge of outboard lift wing, moves forwardand stall warning and stall recognition (stall warning annunciator) activate. Release test switch.
CAUTION: STALLWARN HEAT MUST BE OFF.
(c) Manually move lift transducer forward (up). Ensure horn and light do not operate.
(1.) With lift transducer held forward, place left main gear squat switch to IN-FLIGHT position. Ensure stall warningand stall recognitionactivate. (2.) Release left main gear squat switch and lift transducer vane.
(d)
Perform same test for right wing installation.
(e)
Activate left and right pitot/stall heat switches located on overhead switch panel.
(1.) Ensure lift transducer vane and mounting plate on both wings become warm and ensure stall heat indicator (blue) located on upper portion of the left circuit protection panel illuminates.
CAUTION: DO NOT ACTIVATE Q OVERRIDE SWITCH.
(2.) Turn off both pitot and stall heat switches.
EFFECTIVITY:
040-999PAGE16
Jan10/9027-30-00
PIPER AIRCRAFT
PA-42-720 (Advanced Trainer)
MAINTENANCEMANUAL
A. Elevatorand Tab (continued)
27. Force Applicator Kit Test
The lift computer adjustment potentiometersare factory set to nominal values for activating the pre-stall horn, and the stall recognition light and horn. Actual values for these settings have been determined during flight test of the aircraft and are recorded in the aircraft flight logbook at the time of certification.
Upon replacement of the lift computer or lift transducer, the computer settings must be adjusted, if
different, to the logbook values. To make these adjustments, use Safe Flight Instruments
Corporation Force Application Kit (P/N 1952-3) as follows;
(a)
Attach position bracket to lift transducer cavity.
(b)
Attach proper gauge to positioner for each of the next two setups.
(c)
Check tip gram setting at which the pre-stall warning occurs. If different than the logbook valve, adjust screw #1 (under top cover of lift computer) for proper value of tip grams.
(d)
Check tip gram setting at which the pre-stall recognition light and horn activates. If different than the logbook value, adjust screw #2 (under top cover of lift computer) for proper value of tip grams.
(e)
Remove force application kit.
(f)
Reinstall all panels removed for this test.
EFFECTIVITY:
040-999
27-30-00PAGE17
Nov1/90
PIPERAIRCRAFT
PA-42-720(Advanced Trainer)
MAINTENANCEMANUAL
A. Flaps
1. DescriptionandOperation
Thewingflapcontrolsystemprovidescontinuouscontrolandmonitoringof flappositionand conditionover itsfull range. In additionto limitingbothup anddownovertravel,the systemwill
°
shutoffthe drivingmechanismin the eventof a 5 differentialbetweenrightand leftflapposition, andwill self-monitorand reactappropriatelyduringa criticalcomponentfailurein the control circuitry.
Preselectionof anydesiredflappositionfromfull up (0 °) to full down(30 °) is possibleby
positioningtheselectorcontrol.Theselectorincorporatesafrictiontypedragbraketo holdthe
leveratanydesiredintermediateposition,aswellasballlockdetenteat0°,10°, and30° offlap
extension.Flapsaredeployedmechanically
byasinglemotordrivethruflexibleshaftsconnected to individualballscrewactuators.
Selectionof flap positionmovesthe controlrheostatrelativeto the leftwing flaprheostat,with a
resultantamplifieroutputwhichoperatesflap motorthroughcontactorsK1 and K2, and movesthe
leftandrightflapsto the desiredposition. If at anytime,the amplifiersensesa differentialvoltage
in excessof 0.5 Vdcbetweenleftwingrheostatand rightwingrheostat,the amplifierwill shutthe
°
systemoff. Thisconditioncorrespondsto a maximumdifferentialof 5 offlap position.
A flapfaulttest switchisprovidedto checkcontrolcircuitryfor asymmetricalflap protection,as well
as operationofthe faultlampswitchingtransistor.Activationof this switch,whileflaps arein
motion,givesa falsesignaltothe rightsidefollowerpotentiometer,simulatinganout-of-sync
conditionand causingthe amplifierto shutthe systemoff andilluminatethefault light. Releaseof
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