Propeller Owner’s Manual
115N
INSPECTION AND CHECK
61-00-15
Page 5-12
Rev. 24 Dec/20
(2) Periodic Ground Idle RPM Check
NOTE: The accuracy of the tachometer is critical to
the safe operation of the aircraft. Refer to
the section, “Tachometer Calibration” in the
Maintenance Practices chapter of this manual
for important information.
(a) Perform the RPM check in accordance with the
Airplane Flight Manual or Airplane Flight Manual
Supplement.
1 Refer to the Airplane Flight Manual or Airplane
Flight Manual Supplement to determine if there
are any propeller RPM restrictions or limitations.
(b) Perform an engine run up and determine if the
engine and/or propeller rigging permits operation of
the propeller below the minimum specified propeller
idle RPM.
(c) If the propeller cannot be operated below the
minimum specified propeller idle RPM, no further
action is required.
(d) If the propeller can be operated below the minimum
specified propeller idle RPM:
1 Refer to Figure 5-1 for corrective action
requirements, and Figure 5-2 for an example of
a ground idle RPM check evaluation.
2 The corrective action is based on the amount the
RPM is below the minimum propeller idle RPM
and the total hours of operation the propeller has
accumulated.
a Figure 5-1 applies to an aircraft that is
operated in conventional service. “Hours
of Operation” refers to the total number
of hours the propeller is operated on an
engine that has an improper RPM setting. It
is not the number of hours the propeller is
operated in a restricted range, which will be
less than the total hours of operation.
