FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 8. Engines, Fuel, Exhaust, and Propellers | 5. Inspection of Propellers | 8-95. Tachometer Inspection
AC 43.13-1B
9/8/98
torquing procedures require all bolt threads to
be dry, clean, and free of any lubrication be-
fore torquing.
b. Controllable Pitch.
(1) Inspect controllable pitch propellers
frequently to determine that all parts are lubri-
cated properly. It is especially recommended
that all lubrication be accomplished in accor-
dance with the propeller manufacturer’s in-
structions.
in the manner specified by the propeller manu-
facturer. On makes and models with a grease
fitting on the hub, before greasing the hub re-
move the grease fitting opposite the one to
which you are going to add grease. This will
allow the excess grease and pressure to exit
through the grease fitting hole rather than the
hub seal.
(6) Fiber-block, pitch-change mecha-
nisms should be inspected for deterioration, fit,
and the security of the pitch-clamp forks.
(2) Complete inspection/servicing re-
quires the removal of the spinner for examina-
tion and servicing of the propeller hub and
blade clamp area. All inspections and servic-
ing of the pitch control mechanism should
follow the recommendations of the propeller,
engine, and airframe manufacturers. Propel-
lers must be in compliance with applicable
AD’s and manufacturer’s SB’s.
(3) The hub, blade clamps, and pitch
change mechanisms should be inspected for
corrosion from all sources, including rain,
snow, and bird droppings that may have en-
tered through the spinner openings. Examine
the hub area for oil and grease leaks, missing
grease-fitting caps, and leaking or missing
grease fittings.
(4) Propeller domes should be checked
for leaks, both at the seals and on the fill valve
(if so equipped). The dome valve may be leak-
tested by applying soapy water over the fill
valve end. Domes should be serviced only
with nitrogen or dry air in accordance with the
manufacturer’s recommendations. When pro-
peller domes are inspected and found filled
with oil, the propeller should be removed and
inspected/repaired by an appropriately-rated
repair facility.
(7) Certain models of full-feathering
propellers use spring-loaded pins to retain the
feathered blade position. Spring and pin units
should be cleaned, inspected, and relubricated
per the manufacturer’s recommendations and
applicable AD’s.
(8) Pitch change counterweights on
blade clamps should be inspected for security,
safety, and to ensure that adequate counter-
weight clearance exists within the spinner.
8-95. TACHOMETER INSPECTION.
Due to the exceptionally high stresses that may
be generated by particular propeller/engine
combinations at certain engine revolutions per
minute (RPM), many propeller and aircraft
manufacturers have established areas of RPM
restrictions and other restrictions on maximum
RPM for some models. Some RPM limits do
not exceed 3 percent of the maximum RPM
permitted, and a slow-running tachometer can
cause an engine to run past the maximum
RPM limits. Since there are no post-
manufacture accuracy requirements for engine
tachometers, tachometer inaccuracy could lead
to propeller failure, excessive vibration, or un-
scheduled maintenance. If the tachometer ex-
ceeds 2 percent (plus or minus) of the tested
RPM, replace it.
(5) It is especially recommended that all 8-96.8-106. [RESERVED.]
lubrication be accomplished at the periods and
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