Time of starts and stops, and total time
22.214.171.124 Overspeed feather test. The pro-
peller shall be subjected. to an overspeed feather
Total test time.
test consisting of 25 cycles of operation of the
Engine speed, rpm.
control mechanism. The propeller shall be as-
Engine actual shaft horsepower.*
resembled with counterweighted blades and the
test cycles shall consist of the following:
Engine case or gearbox vibration at points
Initiation of feathering action shall be ac-
shown on installation drawing, mils.
complished at 141 percent of maximum
Fuel flow, lbs/hr.*
rated rpm from the low pitch stop blade
Specific fuel consumption.
angle. The rpm shall be reduced at a linear
Fuel inlet pressure, psi.
rate from 141 percent at the low-pitch stop
M a i n or manifold pressure, psi or inches -
blade angle to 120 percent at 45-degree
blade angle. The rpm shall be maintained
P r i m a r y pump pressure, psi.
at 120 percent for the remainder of the
Transient recovery time.*
Engine bleed opening point.x
The propeller shall demonstrate that feathering
Secondary pump pressure, psi.
can be accomplished at the above conditions to
Oil inlet pressure, psi.
overcome the encountered maximum centrifugal
Engine or gearbox oil outlet pressure, psi.
twisting moment in normal and emergency op-
Engine or gearbox main oil pressure, psi.
Engine case vent pressure, psi.
4.5.2 50-hour engine test.
Compressor inlet and discharge pressure,
126.96.36.199 Test conditions.
188.8.131.52.1 Test apparatus The following test
0il inlet temperature, °F.
apparatus shall apply for all 50-hour engine
Engine or gearbox oil outlet temperature,
tests, as applicable.
184.108.40.206.1.l Engine test stand. The 50-hour
Torque bearing temperature, oF.
engine test of the propeller shall be conducted
Turbine inlet temperature, oF.*
on the model of the engine specified in the con-
Compressor inlet and discharge tempera-
tractor's model specification, in an engine test
ture, oF .
stand, unless otherwise approved by the procur-
Condition or power lever positions, degrees.
ing activity. The stand shall include provisions
to mount the engine and accurately control en-
gine temperatures, pressures, speed, and fuel
rates, so that desired power conditions may be
Negative torque signal operation.
maintained during propeller testing.
Ambient temperature, oF.
220.127.116.11.1.2 Automatic recording equipment.
Measured recording-oscillograph stress
Automatic recording equipment shall be used
to record data during the execution of that part
Propeller pitch pressure, psi.
of the 50-hour engine test requiring the evalua-
Propeller speed, rpm.*
tion of time versus propeller and engine vari-
Propeller operating fluid temperature, oF.
ables. Other recording apparatus, if used, shall
Blade angle, degrees.*
be capable of synchronization with the auto-
matic recording equipment.
*Note: For steady-state and transient calibra-
tions, items marked with an asterisk, as appli-
18.104.22.168.2 Test propeller. The same test pro-
cable, need be recorded and such other data as
peller shall be used for the entire 50-hour test.
may be pertinent to the installation.
22.214.171.124.3 Test data. During the 50-hour en-
126.96.36.199 Instrumentation. The instrumenta-
gine test, the following data shall be recorded,
tion and techniques used for the required vibra-
where applicable, at intervals not greater than
tory stress survey of the 50-hour engine test
Time of day.
shall be as specified in 188.8.131.52. Instrumentation