Piper CHEROKEE WARRIOR PA-28-151 1995 Maintenance Manual page 277

PIPER CHEROKEE WARRIOR SERVICE MANUAL
8-50. STATIC RPM TEST PROCEDURE.
The maximum static rpm value for a fixed pitch propeller equipped aircraft provides an indication that
the engine/propeller combination is meeting rated power output.
Low static rpm indicates a low engine power or incorrect propeller (higher pitch/longer diameter)
while a high rpm indicates high engine power or incorrect propeller diameter), any of which is not desirable.
For this reason it is important that each propeller combination meets the criteria of this section. However,
many factors influence engine power and therefore the actual static rpm can change significantly. This section
provides a procedure whereby accurate and repeatable static rpm values may be obtained.
8-51. SCOPE.
This section describes the ground test procedure for determining the maximum static rpm value for
each fixed pitched propeller aircraft listed in Table VIII-III, Propeller Applicability.
8-52. EQUIPMENT.
The following equipment is required to accomplish this ground test procedure:
1. Vu-thru tachometer
2. Instrument or means to obtain outside air temperature and relative humidity or dew point.
The following list of instruments may be used, but are not the only means.
A ATIS
B. Calibrated Thermometer
C. Calibrated Psychrometer
D. National Weather Service
E. Omega Hand Held Hygrometers, models RH-201 and RH-30 or equivalent.
8-53. TEST PROCEDURE.
A simplified test procedure is provided to test static rpm under limited conditions. In the event that t h e
test conditions do not fall within the limits of Table VIII-III and VIII-IV, proceed to the expanded test proce-
dure.
8-54. SIMPLIFIED TEST PROCEDURE.
a. Obtain ambient outside air temperature and dew point.
b. Head aircraft into the wind.
c. Apply full throttle. Avoid prolong runs at full power.
d. Allow oil temperature to reach 180±10 degrees.
e. Record the test static rpm using the Vu-thru tachometer.
f. Using the outside air temperature and dew point enter table VIII-III or VIII-IV, as appropriate, for
the aircraft configuration you are testing and read the corresponding BASELINE rpm value. With baseline
value and tested static rpm, proceed to Paragraph 8-56, Test Results.
Use the temperature and dew point values on the table which
most closely correspond to the test condition. Interpolate base -
line rpm if temperature and/or dew point fall equally between
two or more blocks.
8-55. EXPANDED TEST PROCEDURE.
The worksheet found on the following page should be copied and the copy used to document the fol-
lowing expanded test procedure.
a. Obtain ambient outside air temperature and relative humidity.
Added: February 28, 1995
NOTE
1L13
Island Enterprises
POWER PLANT