TM 55-4920-328-13
Section II. ENGINE TEST PROCEDURES
3-6. Use of Test Procedures.
The test procedures provided in this section are
intended for use at the intermediate support level of
maintenance. The accomplishment of the complete test
of an engine is left to the discretion of the Maintenance
Officer. Selection of only that portion of the applicable
test procedure will tend to isolate the reported
malfunction. Additional testing of the engine may be
made to ensure that all operating parameters fall within
acceptable limits. In many cases, a partial test which
will diagnose a reported malfunction will provide
sufficient information to accomplish the required repair
at the intermediate level. This action will allow the
engine to be returned to service and preclude the
necessity for premature overhaul of the unit.
3-7. Typical Engine Test Procedures
WARNING
Ensure that personnel and unneeded
equipment are removed from the
plane of rotation of the gas producer
and power turbine rotors of an
engine during a test. Ensure that
personnel and equipment are denied
access to the vicinity of the exhaust
stream of the engine during a test.
Failure to observe this warning may
result In damage to the equipment
and
serious
or
fatal
injury
to
personnel.
The following procedures provide the information for
METS operation during test of a typical gas turbine
engine. Refer to the applicable engine technical manual
for information of specific operating parameters.
Proceed as follows:
a. Install the applicable engine accessories on the
engine in accordance with the procedures specified in
chapter 2 of this manual. Recheck all installation points
for security of attachment.
b. Install the engine in the engine test dolly assembly
as outlined in chapter 2. When required, complete the
installation of the engine accessories and dress
hardware.
c. Tow the engine test dolly assembly to the test site
and disconnect and remove the vehicle.
d. Use the crane assembly and a suitable sling, to lift
the engine test dolly assembly and engine to a position
above the forward end of the test trailer assembly.
Lower the units and secure the engine test dolly
assembly to the test trailer assembly as outlined in
chapter 2. Remove the sling and rotate the crane
assembly out of the way.
e. Interconnect the engine and data acquisition
assembly as outlined in chapter 2.
f. Interconnect the control cab assembly and the data
acquisition assembly as directed in chapter 2.
g. Interconnect the water brake assembly water
system as specified in chapter 2.
h. Interconnect the fuel system, air system, and oil
system as outlined in chapter 2.
i. Accomplish the instructions specified in paragraph
2-9, Preliminary Checkout Prior to Test. At the
conclusion of this step, leave all systems energized.
NOTE
A minimum of two technicians are
required to accomplish the test of al,
engine. One technician will perform
the procedural steps; the other will
record the results of each step on the
engine inspection test log.
j. Energize the AUTO FUEL/EMERG FUEL
switchlight unit (25, figure 1-24) on the operator's panel
assembly 3A3 (34) to the position required by the
applicable engine test procedure.
k. Energize the ENGINE FUEL SOLENOID
switchlight unit (30).
I. If required, momentarily depress the TIMER
'RESET switchlight unit (36) to reset the elapsed time
indicator (37) to zero.
m. Manually pre-set the NI throttle lever on the
engine fuel control quadrant to the specified percent of
Ground Idle to be displayed on the THROTTLE
POSITION indicator M2 (8). For T73 engine test only,
retract the NI master control unit to the fully closed (aft)
position.
n. Manually pre-set the overspeed governor on the
engine to the minimum position.
3-7
