Engine Rigging Checks And Adjustments; Ground Idle Adjustments; Flight Idle Adjustments; Propeller Governor Check - Thrush Aircraft S2RHG-T65 TURBO THRUSH Maintenance Manual

THRUSH AIRCRAFT, INC – MODEL S2RHG-T65 TURBO THRUSH
B. Move the propeller control lever in the cockpit to FEATHER and ensure that the
skirt below the governor speed set lever (Fig. 4-2, Item 9) fully depresses the
feathering valve plunger.
Upon completion of rigging and prior to engine running, a functional check of the
system's operation should be carried out. This check should include the operation of all
controls throughout their entire operating range and checking for freedom of all
movement, freedom from binding, security and safety.

ENGINE RIGGING CHECKS AND ADJUSTMENTS

This section details various engine and propeller functional checks, which are
performed after engine control rigging and engine run up.
GROUND IDLE ADJUSTMENTS (Ref. Fig. 4-7)
A. Run engine to bring oil temperature within normal operating ranges (38° C
minimum).
B. Set condition lever to LOW-IDLE. and power control lever in IDLE. Check Ng
tachometer for a reading of 59% Ng for PT6A-45A, -45B, -45R and PT6A-65AG, -
65AR, -65B or 62% Ng for PT6A-60AG. If it is not, proceed as follows:
1. Loosen FCU lever clamp screw (Detail A) then loosen the upper low idle
adjustment screw and tighten the lower low idle screw by an equal number
of turns to INCREASE idle speed. One flat allen head screw will change idle
speed 4%.
2. Tighten the FCU lever clamp screw.
After adjusting idle, MAX FORWARD and MAX REVERSE
settings may require readjustment.
A. Set condition lever to HIGH-IDLE. Condition lever (Fig. 4-3, #8) must contact
HIGH-IDLE stop screw (Fig. 4-7). An angle of 42 degrees ± 4 degrees
represents the angle formed between the CUT-OFF and HIGH-IDLE positions at
the lever.
B. Set HIGH-IDLE to 69% Ng. For the PT6A-60AG, adjustments can be made by
turning nuts on the cam follower assembly (Fig. 4-7). Adjusting the nuts out will
rotate the FCU lever (Fig. 4-3, Item 10) in a clockwise direction and increase Ng
and conversely, turning the nuts in will rotate the FCU lever in a counterclockwise
direction and decrease Ng. Turning the nut one turn will increase or decrease
HIGH-IDLE speed by 1.5%. (Note: PT6A-45A, -45B, -45R and PT6A-65AG, -
65AR, -65B High-Idle is adjusted by turning High-Idle Stop in to increase, out to
decrease RPM.)
A. Set power lever to IDLE.
Effective: 9/16/05
AIRCRAFT MAINTENANCE MANUAL
*NOTE*

FLIGHT IDLE ADJUSTMENTS

PROPELLER GOVERNOR CHECK

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