Cessna 150M - Indefinite Storage; Inspection During Storage; Returning Aircraft to Service

NOTE
Corrosion preventive mixture consists of one
part compound MIL-C-6529, Type I, mixed
with three parts new lubricating oil of the
grade recommended for service. Continental
Motors Corporation recommends Cosmoline
No. 1223, supplied by E. F. Houghton & Co.,
305 W. LeHigh Avenue, Philadelphia, Pa.
During all spraying operation corrosion mix-
ture is pre - heated to 221 ° to 250 ° F .
c. Immediately after filling the oil sump with cor-
rosion preventive mixture, fly the aircraft for a
period of time not to exceed a maximum of 30 min-
utes.
d. With engine operating at 1200 to 1500 rpm and
induction air filter removed, spray corrosion pre-
ventive mixture into induction air box, at the rate of
one-half gallon per minute, until heavy smoke
comes from exhaust stack, then increase the spray
until the engine is stopped.
ICAUTION\
Injecting corrosion-preventive mixture too
fast can cause a hydrostatic lock.
e. Do not rotate propeller after completing step
"d."
f. Remove all spark plugs and spray corrosion-
preventive mixture, which has been pre-heated to
221 ° to 250°F, into all spark plug holes to thorough-
ly cover interior surfaces of cylinders.
g. Install lower spark plug or install solid plugs,
and install dehydrator plugs in upper spark plug
holes. Be sure that dehydrator plugs are blue in
color when installed.
h. Cover spark plug lead terminals with shipping
plugs (AN4060-1) or other suitable covers.
i. With throttle in full open position, place a bag
of
desiccant in the carburetor intake and seal open-
ing with moisture resistant paper and tape.
j. Place a bag of desiccant in the exhaust tail-
pipe(s) and seal openings with moisture resistant
tape.
k. Seal cold air inlet to the heater muff with mois-
ture resistant tape.
1. Seal engine breather by inserting a protex plug
in the breather hose and clamping in place.
m. Seal all other engine openings exposed to atmos-
phere using suitable plugs or non-hygroscopic tape.
NOTE
Attach a red streamer to each place plugs or
tape is installed. Either attach red streamers
outside of the sealed area with tape or to the
inside of the sealed area with safety wire to
prevent wicking of moisture into the sealed
area.
n. Drain corrosion-preventive mixture from engine
sump and reinstall drain plug.
NOTE
The corrosion-preventive mixture is harmful
to paint and should be wiped from painted sur-
faces immediately.
o. Attach a warning placard on the throttle control
knob, to the effect that the engine contains no lubri-
cating oil. Placard the propeller to the effect that it
should not be moved while the engine is in storage.
p. Prepare airframe for storage as outlined in
paragraph 2-10 thru step Iff. " •
NOTE
As an alternate method of indefinite storage,
the aircraft may be serviced in accordance
with paragraph 2-10 providing the aircraft is
run-up at maximum intervals of 60 days and
then reserviced per paragraph 2-10.
2-14. INSPECTION DURING STORAGE. Aircraft
in indefinite storage shall be inspected as follows:
a. Inspect cylinder protex plugs each 7 days.
b. Change protex plugs if their color indicates an
unsafe condition.
c. If the dehydrator plugs have changed color in one
half of the cylinders, all desiccant material in the
engine shall be replaced with new material.
d. Every 6 months respray the cylinder interiors
with corrosion-preventive mixture.
NOTE
Before spraying, inspect the interior of one
cylinder for corrosion through the spark
plug hole and remove at least one rocker box
cover and inspect the valve mechanism.
2-15. RETURNING AmCRAFT TO SERVICE. After
indefinite storage, use the following procedure to
return the aircraft to service.
a. Remove aircraft from blocks and check tires for
correct inflation. Check for correct nose gear strut
inflation.
b. Check battery and install.
c. Remove all materials used to seal and cover
openings.
d. Remove warning placards posted at throttle and
propeller.
e. Remove and clean engine oil screen, then re-
install and safety. On aircraft that are equipped
with an external oil filter, install new filter element.
f. Remove oil sump drain plug and drain sump.
Install and safety drain plug.
NOTE
The corrosion-preventive mixture will mix
with the engine lubricating oil, so flushing
the oil system is not necessary. Draining
the oil sump will remove enough of the cor-
rosion-preventive mixture.
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