Propeller Owner’s Manual
139
INTRODUCTION
61-00-39
Page 1-11
Rev. 17 Apr/20
9. Component Life and Overhaul
(Rev. 1)
WARNING:
CERTAIN PROPELLER COMPONENTS
USED IN NON-AVIATION APPLICATIONS
ARE MARKED WITH DIFFERENT PART
NUMBERS TO DISTINGUISH THEM
FROM COMPONENTS USED IN AVIATION
APPLICATIONS. DO NOT ALTER THE PART
NUMBERS SHOWN ON PARTS DESIGNATED
FOR NON-AVIATION APPLICATIONS OR
OTHERWISE APPLY THOSE PARTS FOR USE
ON AVIATION APPLICATIONS.
A. Component Life
(1) Component life is expressed in terms of hours of service
(Time Since New, TSN) and in terms of hours of service
since overhaul (Time Since Overhaul, TSO).
NOTE: TSN/TSO is considered as the time
accumulated between rotation and landing,
i.e., flight time.
(2) Time Since New (TSN) and Time Since Overhaul
(TSO) records for the propeller hub and blades must be
maintained in the propeller logbook.
(3) Both TSN and TSO are necessary for defining the life of
the component. Certain components, or in some cases
an entire propeller, may be “life limited”, which means
that they must be replaced after a specified period of use
(TSN).
(a) It is a regulatory requirement that a record of the
Time Since New (TSN) be maintained for all life
limited parts.
(b) Refer to the Airworthiness Limitations chapter in the
applicable Hartzell Propeller Inc. Owner’s Manual for
a list of life limited components.
(4) When a component or assembly undergoes an overhaul,
the TSO is returned to zero hours.
(a) Time Since New (TSN) can never be returned to
zero.
(b) Repair without overhaul does not affect TSO or TSN.
