(g)
Attach trim tab rod assemblies to trim actuator withappropriatebolts, washers, nuts, and cotter pins.
(h)
Adjust cable tension and trim tab travel using specification in Figure 501.
16.Rigging of Elevator Trim
(a) Complete the following steps during installation or as a preadjustment check to adjust elevator trim:
(1.) Remove accesspanels on left and right side of fuselage aft of pressure bulkheadatF.S. 339.50,accesspanels on vertical fin, and bullet assembly on vertical stabilizer. Carefully removeaccess panel in control pedestal floor.
(2.) Ensure trim cablesare properly wrapped.
(3.) Ensure trim cable tension is set according to specifications in Figure 501.
(4.) Ensure actuating screws are positioned to anti-rotation bushingsare at midpoint of slots.
(b) Rotate trim control wheel in cockpit to full nose up position. Ensure tumbuckleterminaldoes not strike pulley.
NOTE: If turnbuckle terminal does strike center pulley before actuating screwsare at their stops, disconnect trim tab rods and rotate screwsin drums until screwsare at stops before terminal of tumbuckle strikescenter pulley. It may be necessary to back off trim wheel to reinstall trimtab rods and anti-rotation bushings.
(c)
Adjusttrim tab rods so tabs are properly positioned with elevators in neutral.
NOTE: Rig elevators with elevators in neutral (pinned at aft sector) and ensure RH elevator trailing edge is aligned with LH elevator trailing edge. Adjust length of trim tab for 0.12 ± 0.12 inch trailing edge up from RH tab, as measured oninboard trailing edge of tab.
(d)
Checkrod ends for proper thread engagement.
(e)
Withelevator rigging tool (P/N 72046) installedon left stabilizerand elevator in neutral, rotate trimwheel in cockpit for tab travels specified in Figure 501.
(f)
Coordinatetrim wheel indicatorwith tab position.
(g)
Use tool L73035 and a dial torque wrench to check trim system friction at pedestal by removing trim wheel and attaching tool and torque wrench to splined shaft. Friction must not exceed 9 inch-poundswhentested in either direction, at any point between limits.
EFFECTIVITY:
040-999
PAGE12 27-30-00
Jan10/90
PIPERAIRCRAFT
PA-42-720(AdvancedTrainer)
MAINTENANCEMANUAL
A. Elevatorand Tab (continued)
17. ElevatorTrimSystemFrictionCheck
(a)
Removeelevatortrim control wheelfromelevatortrimactuatorshaftin control pedestal(Figure 601).
(b)
AttachPAC tool number 73035and a dial torque wrenchto splined shaft of elevatortrim actuator.
(c)
Moveelevatortrimactuatorto its travel limits, in both up and the down directions,usingtorque wrench.Frictionmust not exceed 9 inch-pounds atany point
whentested in either direction, betweenlimits.
(d) Locate problem area. Repairorreplacedefectivepartsif friction exceeds9 inch-pounds at any
point.
18.Free Play Check of Elevator Tabs
(a)
Ensuretrim tab is in neutral.
(b)
Ensuretotaltabfree play, withtab neutral, does notexceed0.126inchmaximummeasuredat tab trailing edge.
19. Inspectionof Aft Elevator Trim Actuator
(a)
Ensurebearingsinstalledin trim drum move freely.
(b)
Ensureendplay on trim drumis0.001to 0.003 inch. Use oneof the followingmethodsto ensureproper end play:
(1.) Placewasher 49981-9, or washer 59486-2,-3, or -4, as required, betweenbearingand drum. (2.) Place laminated shim 70153-2, as required, betweentrim drum and trim drum bracket.
(c)
Ensure0.01inch minimum loosenessbetweenactuatorframe.Trimdrumbracketguide assembly.
(d)
Ensureforcerequiredto actuate unitat room temperature(60°F to 850F) does notexceed1.5 poundsbreak-outforceor1 pound pullon either cable throughoutstroke.At-40°F, these forcesmust not exceed4.5poundsand3 pounds, respectively.
20.Trim Systems' Controls and Indicators
Thetrim controls for aileron, rudder,and elevator trim systems are mounted in the control pedestal. Theaileron and ruddertrimcontrolsare connected to cabledrumsby shafts with aileron trim drum mountedinpedestal,andrudder trim drumon a channel platemountedunderpedestal.The elevatortrim control drumismounteddirectlyto elevator controlassemblyand must be removed alongwith the assembly.
21. Removalof Trim Controls (Figure 402)
(a)
Removeflushheadset screw retainingcontrolknobor wheel to splinedshaft.Carefullypull wheel/knobfrom shaft.
(b)
Removeand install elevatortrimcontrolas follows:
(1.) Removecontrolwheeland remove six retaining screwsholdingindicatorplateto the controlhubassembly.
(2.) Block,disconnect,andpullforwardcablesystemthroughaircraft(describedin paragraph onRemovalof the Forward ElevatorTrimSystem).Removefour mounting screwsand pull control assemblyfromcontrolpedestal.
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