Piper Comanche PA-24 Service Manual page 149

H. Time - as used in this manual.
(1) Time-in-service for aircraft components, unless otherwise specified, is a cumulative total of
flight hours or calendar time calculated from the time a new or overhauled component was first
installed in any aircraft, and including:
(a) the aircraft time that elapses from the initial installation to the first removal, if any; and,
(b) the aircraft time that elapses from each subsequent installation to each subsequent
removal, if any; or,
(c) the calendar time elapsed since the installation.
NOTE: Dates stamped on individual components at the time of manufacture are typically
applied to determine shelf life - i.e. the maximum time allowed from manufacture/
assembly/cure until actually installed in an aircraft and are not relevant.
Do not, however; ignore markings applied to life-limited parts when removed with
time and/or cycles remaining on them.
(2) Aircraft time, flight hours, or aircraft hours are the "Hobbs Time" shown on, or calculated
from, the installed "Hour Meter."
04/01/09
PIPER COMANCHE SERVICE MANUAL
1D11
III - INSPECTION