(2.) Determinethe following:
(a.) Pressurealtitude (PA).
(b.) Outsideairtemperature(OAT)in degrees Celsius(C).
(c.) Referto Chart 3. Using PA and OAT,find target torque.
(3.) Set propeller controlleverto maximum rpmposition.
(4.) Increase enginepoweruntil propeller rpm (Np) indicates 1900.
(a.) Checkthatindicatedtorqueis ± 30 foot-poundsof target torque.
(b.) Checkthattorquedifferencebetweenenginesdoesnot exceed 30 foot-pounds.
NOTE: Markall beta nutsand rodswith a marking penor pencilbeforemaking any adjustments.
(5.) Refer to Figure510. To adjust:
(a.) Removepropellerspinner.
(b.) Adjustbetanuts. One flatclockwiseturnresults in 30 foot-pounds torqueincrease.
(e) Reversemaximumpoweradjustment.
(1.) Location: Reversepowerstop on power controlcable(Figure406). (2.) Determine maximumreversepower:
(a.) Runengine.Placecockpit power leversinfullreverseposition. (b.) Notepropellerrpm(Np)and torque (Q) on eachengine. (c.) Findreversehorsepower(hp)by the equation:Npx Qx 0.00019.
1 Check that reversepoweris 180 ± 20 hp.
2 Checkthatreversepowerdifferencebetweenenginesisnot more than 20 hp.
(3.) Referto Figure406. Usereversepowerstopto adjust gapX. Increasinggap will increasetorque. (4.) CheckthatNpdoesnot exceed 1900± 10rpm. To adjust:
(a.) Location:Propellergovernorconstantspeedunit(CSU). Refer to Figure 511. (b.) Disconnectinterconnecting
rodfrom air bleedlinearm. (c.) Movearm rearward (awayfromstop) as far as possibleandsecure.
NOTE: Propellerconstantspeedunitcannotdiscriminatebetween1900rpmin forwardthrustor reverse thrust.
(d.) Startengine.Movecockpitpowerleverforwardto maximum powerstop.
EFFECTIVITY: 040-999
Jan 10/9076-10-00
PIPER AIRCRAFT
PA-42-720 (Advanced Trainer)
MAINTENANCEMANUAL
C. EngineRun Adjustments (continued)
3. Engine Running Adjustments(continued)
(e) Reversemaximumpower adjustment. (continued)
(4.) Check that Np does not exceed 1900 ± 10 rpm. To adjust: (continued)
(e.) Refer to Figure 511. Adjust constant speed unit pneumatic minimumadjustment screw in increments to obtain 1900 ± 10 rpm.
NOTE: Turning constantspeed unit pneumatic minimumadjustmentclockwisecould result in either decreasing or increasing propeller rpm. Same is true with counterclockwise
adjustment.
(f.) Attach interconnecting
rod to air bleed line arm.
(f) Maximumpropeller speed adjustment.
(1.). Location: Propeller governor(referenceFigure1 and Figure 511).
NOTE: Check that nothing interfereswith control linkage providing sufficienttravel to governorcontrolarm.
NOTE: Adjust one engine at a time
(2.) Start engine. Set cockpit propellercontrol lever full forward (high rpm). Check that lever
has a 0.06 inch spring back.
(3.) Advance power lever. Np should increase to, and stabilize at, 2000 rpm.
(4.) Refer to Figure 511. Adjust maximum rpm stop bolt as required. Clockwise adjustment
decreasesrpm.
(g) In flight maximum gas turbine speed (Ng) adjustment.
(1.) Location:
(a.) Woodward Type II fuel control unit: On right side of fuel control unit. See Figure 503. (b.) Woodward Type IIIfuel control unit: Top right of fuel control unit. See Figure 509.
CAUTION: DO NOT EXCEED ENGINE LIMITATIONS WHILE CHECKING MAXIMUM NG IN FLIGHT.
(2.) Obtain maximum cruise flight engine settings from Chart 1.
(3.) In flight, set engine controls for maximum cruise.
(4.) Check that Ng reads 104 percent. To adjust:
(a.) Check accuracy of 1900 rpm torque adjustment. (b.) Adjust maximum forward Ng stop on fuel control unit.
1 Woodward Type II fuel control unit: Refer to Figure 503. One 360°turn of stop bolt results in 0.9 percent Ng change. 2 Woodward TypeIIIfuel control unit: Refer to Figure 509. Ng will change 0.33 percent per flat adjustment.
EFFECTIVITY:
040-999 )76-10-00
PAGE29
Jan 10/90
PIPERAIRCRAFT
PA42-720(Advanced Trainer)
MAINTENANCEMANUAL
C. Engine Run Adjustments(continued)
3. EngineRunningAdjustments(continued)
(g) Inflightmaximumgas turbine speed(Ng)adjustment.(continued)
(5.) Tighten Ng adjustment locknutandsafety.
(h) Featheringdetent plate adjustment
NOTE: Do not permit propellerto feather whenadjustingfeatheringdetentplate.
(1.) Start engines.
(2.) Setpropellercontrolleversto full high rpm.
(3.) Movepower control leversforwarduntilpropellerrpm is 1900.
(4.) Refer to Figure512. Movepropellercontrolleversbackagainstfeather detent.
(5.) Adjust platepositiontoobtain 1500 to 1600propellerrpm.
(6.) Pull propellercontrolspastdetent into featherposition.Checkthat propeller is feathered.
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本文链接地址：夏延飞机维护手册 Cheyenne IIIA PA-42-720 AMM 2(154)
