Propeller Owner’s Manual
147
INSPECTION AND CHECK
61-00-47
Page 5-36
Rev. 17 Sep/20
C. Foreign Object Strike/Ground Strike
(Rev. 1)
(1) General
(a) A foreign object/ground strike can include a broad
spectrum of damage, from a minor stone nick to
severe ground impact damage.
1 A conservative approach in evaluating the
damage is required because there may be
hidden damage that is not readily apparent
during an on-wing, visual inspection.
(b) A foreign object/ground strike is defined as:
1 Any incident, whether or not the engine is
operating, that requires repair to the propeller
other than minor dressing of the blades.
a Examples of foreign object/ground strike
include situations where an aircraft is
stationary and the landing gear collapses
causing one or more blades to be
significantly damaged, or where a hangar
door (or other object) strikes the propeller
blade(s).
b These cases should be handled as foreign
object/ground strikes because of potentially
severe side loading on the propeller hub,
blades, and retention bearings.
2 Any incident during engine operation in which
the propeller impacts a solid object that causes
a drop in revolutions per minute (RPM) and
also requires structural repair of the propeller
(incidents requiring only paint touch-up are
not included). This is not restricted to propeller
strikes against the ground.
3 A sudden RPM drop while impacting water,
tall grass, or similar yielding medium, where
propeller blade damage is not normally incurred.
(c) In the event of a foreign object/ground strike, an
inspection is required before further flight.