Hartzell HC-E4 3 Series Owner's Manual page 5

Propeller Owner's Manual
147
For operators of uncertified or experimental aircraft
an even greater level of vigilance is required in the
maintenance and inspection of the propeller. Experimental
installations often use propeller-engine combinations that
have not been test and approved. In these cases, the
stress on the propeller and, therefore, its safety margin is
unknown. Failure could be as severe as loss of propeller
or propeller blades and cause loss of propeller control
and/or loss of aircraft control.
Hartzell Propeller Inc. follows FAA regulations for propeller
certification on certificated aircraft. Experimental aircraft
may operate with unapproved engines or propellers or
engine modifications to increase horsepower, such as
unapproved crankshaft damper configurations or high
compression pistons. These issues affect the vibration
output of the engine and the stress levels on the propeller.
Significant propeller life reduction and failure are real
possibilities.
Frequent inspections are strongly recommended if
operating with a non-certificated installation; however,
these inspections may not guarantee propeller reliability,
as a failing device may be hidden from the view of the
inspector. Propeller overhaul is strongly recommended to
accomplish periodic internal inspection.
Inspect the propeller/blades in accordance with the
applicable operation/maintenance documents.
Page 3
61-00-47
MESSAGE
Rev. 17 Sep/20