FINAL ENGINE TEST
This chapter provides instructions for con-
ducting fuctional tests following repair or re-
placement of parts.
10-2. Preparation for Test.
Engine testing maybe accomplished with
the engine installed in the airframe or on a
mobile engine test stand.
a. Engine Installation in Airframe. Install
the engine in the airframe as outlined in the ap-
plicable aircraft maintenance manual TM 55-
b. Engine Installation on Test Stand. In-
stall the engine on the mobile engine test
stand, Part No. LTCT10465-02 (NSN 4920-00-
167-9178), as outlined in TM 55-4920-328-13.
10-3. Instrumentation Requirements.
Engine testing may be accomplished using
no more than standard aircraft instrumentation
to monitor the following parameters.
a. Turbine Outlet Temperature (0-1000°C)
b. Output Shaft Torque (0-110 psi)
c. Oil Pressure (0-150 psi)
d. Gas Producer (N1) Speed (0-110%)
e. Power Turbine (N2 Speed (0-120%)
10-4. Engine Motoring Procedure.
a. Engine Installed in Airframe.
(1) Disconnect the power input lead from
the ignition exciter or pull IGN ENG circuit
(2) Ensure that the throttle (twist grip) is in
the FUEL CUTOFF position.
(3) Ensure that the collective pitch control
is at the minimum position.
(4) Press and hold the starter-ignition but-
ton to motor the engine. Release the button to
b. Engine Installed on Test Stand.
(1) Prepare the test stand for operation as
outlined in TM 55-4920-328-13.
(2) Place the N1 throttle lever to the zero
degree position as indicated on the throttle
(3) Place the governor lever to the mini-
Do not press the ignition switch.
Ensure that lubricating oil is avail-
able at the engine oil inlet port.
Damage to the engine could result
if lubricating oil was not available
at the oil inlet port at the start of the
(4) Press the start switch to motor the en-
gine. Press the start switch a second time to
10-5. Engine Operating Procedures.
Refer to applicable TM 55-1520-
228-10 for starting, operating, and
shutdown procedures when the en-
gine is to be tested in the airframe.
The following operating procedures apply
when the engine is installed on the test stand.