Flight Controls
A. Descriptionand Operation
Theprimaryflight controls are conventionaltypeoperatedby dual control columns and rudder pedals.
The control columnsfunctionona lever arm principle attachedto a crossover shaft (torque tube) mountedunderthe cockpit floor. Thecrossovershaftacts as the axis of rotation for the two columns andhousestheroller chain that interconnects
the two control wheels.The control columns contain hardwarefor adjustment of control wheelsandaileronprimarydrivemechanism.Thelinkagesto the aileronandelevator control sectorsare contained underthe left side of the floor.
Theailerons are actuated by the pilot and copilot controlwheels through the roller chainwhich drives a lever located in the pilot's control column. This lever transmits the control wheelstravel to the aileron controlsectorthroughthe link, bellcrank, and anotherlink. Cables runfrom the sector to aileron
bellcranksin the wings.
Theelevatorsare controlled by control columnsthroughthe crossover shaft.An arm, extending from the pivot fitting located onthe left side of the crossovershaft,transmitscontrolcolumntravel through a linkto the forward elevatorcontrolsector.Thecontrol cables forthe elevator controlsystemrun from theforward control sectorat F.S. 93.30to the aft control sector atF.S. 373.10. The aft control sector is connectedto a long push-pulltubewhich reaches upthroughto the top of the verticalstabilizerwhere it bolts to the elevator controlhorn.
Attachedto the left set of rudder pedalarmsare tubes connectedto a bellcrank whichis attached to the pressure bulkheadat F.S. 57.00. The rudder controlsectorat W.L. 18.00is driven by a tube runningfromthe bellcrank. Controlcables run from the controlsectorto the rudder sector, whichis attacheddirectly to the rudder.
Theaileron,elevator,and rudder trimcontrolsaremountedon the pedestal alongwith position indicatorsforeachsystem. As each control ismoved,cablewrappeddrumsrotate,andin turn they actuatethe particular trim system being operated.
TheCalco type flap mechanism is described in detail in the 27-50-00ofthis chapter.
EFFECTIVITY:
040-999
27-00-00 Jan 10/90
PIPERAIRCRAFT
PA-42-720 (Advanced Trainer)
MAINTENANCEMANUAL
B. StandardProcedures
The following tips are helpful when removing and installing variousassemblies:
1.
Leveland place airplaneon jacks during riggingand adjustment of controls.
2.
Removeturnbucklebarrels from cable ends before withdrawing cablesthrough structures.
3.
Tiea cord to cable end before drawing cable throughstructuresto facilitate reinstallationof cable.
4.
Turnbucklestationsare given at neutral position.
5.
Beforedisconnecting,use a felt markerto mark cable ends, etc.
6.
Assembleand adjust tumbucklesto ensure each terminal is screwed in approximately equal distanceinto barrel. During adjustment, do not turn terminals so a permanent twist is put in cables.
7.
Whenturnbucklesare set to correct cable tension, nomore than three threads must be exposed from either end of turnbuckle barrel. Check locking clips for proper installation by removing clipsusing fingers only. Both locking clipscan be inserted in the same turnbucklebarrel hole or installedin opposite holes. Locking clips installedand removed must be scrapped.
8.
When push rods or rod ends are provided with an inspectionhole, the screw must be screwed in enoughto pass the inspection hole.This is determinedvisuallyorby inserting a piece of wire into the inspection hole.Whereno inspection holeis provided, a minimum 3/8 inch threadmust be engaged.
9.
Cabletension must be measured with appropriate surfacecontrolin neutral position.
NOTE: Perform a friction check of the system whenever elevator,rudder,or aileron control system is serviced.
NOTE: Cable rigging tensions specified in the following paragraphsmust be corrected to ambient temperaturein area where tension is being checked (referto Chart 1).
10.
Ensureall cable guard pins are installed properly and are not interfering with control cable travel.
CAUTION: WITH RIGGING PINS INSTALLED, CLAMP THE BELLCRANK, SECTOR,OR ASSEMBLY SO WHEN CABLES ARETIGHTENEDTHE LOAD IS NOT TAKEN UP BY THE PIN. ENSURE PIN IS FREE AT ALL TIMES. IT IS RECOMMENDED THAT CABLESARE CLAMPED NEARSECTOR, INSTEAD OF CLAMPING THE SECTOR. 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：夏延飞机维护手册 Cheyenne IIIA PA-42-720 AMM 1(96)
