Propeller Owner's Manual
115N
TESTING AND TROUBLESHOOTING
61-00-15
Page 4-11
Rev. 24 Dec/20
H. Vibration
CAUTION 1: ANY VIBRATION THAT OCCURS
SUDDENLY, OR IS ACCOMPANIED BY
UNEXPLAINED OIL LEAKAGE SHOULD
BE INVESTIGATED IMMEDIATELY
BEFORE FURTHER FLIGHT.
CAUTION 2: VIBRATION PROBLEMS BECAUSE OF
PROPELLER SYSTEM IMBALANCE ARE
NORMALLY FELT THROUGHOUT THE
RPM RANGE, WITH THE INTENSITY OF
VIBRATION INCREASING WITH RPM.
VIBRATION PROBLEMS THAT OCCUR
IN A NARROW RPM RANGE ARE A
SYMPTOM OF RESONANCE THAT
IS POTENTIALLY HARMFUL TO THE
PROPELLER. AVOID OPERATION UNTIL
THE PROPELLER CAN BE CHECKED
BY A CERTIFIED PROPELLER REPAIR
STATION WITH THE APPROPRIATE
RATING.
(1) Check:
(a) Control surfaces, cowl flaps, exhaust system,
landing gear doors, etc. for excessive play, that may
be causing vibration that is unrelated to the propeller
(b) Isolation of engine controls and lines
(c) Engine mount wear
(d) Uneven or over-lubrication of the propeller
(e) Proper engine/propeller flange mating
(f) Blade track:
1 Refer to the section, "Blade Track" in the
Inspection and Check chapter of this manual.
