Page 44 - Aeronca 7A Interactive Service Manual

SERVICE HELPS AND HINTS NO. 40

September 8, 1948

TO: All Aeronca Distributors and Dealers

SUBJECT: Oleos on models 7AC, 7BCM, 7CCM, 7DC, 11AC, 11BC and 11CC

There are going to be a great many embarrassed pilots when they land one of the subject airplanes and
find themselves with a folded-up landing gear. Why? It sure isn’t the pilot’s fault – it’s the fault of the person
owning the plane not seeing to it that the oleos received proper maintenance.

An aircraft engine won’t run long without oil – it’ll seize in no time. Oleos won’t stand up either without
fluid – they’ll break!

The landing load factor runs extremely high when the fluid gets low in the oleos – ¾ full is almost as bad
as no fluid at all! Oleos must be kept full of fluid, and – it must be proper fluid – NOT water – NOT grease
– but AN-VV-O-366 hydraulic fluid or equivalent.

Why? Oleos depend on fluid to dampen the loads on the integral parts of the oleo and attaching fittings on
either impact or rebound. The oleo spring alone is not enough – the lack of fluid results in a hammering
effect on the piston, piston tube, attaching fittings and fuselage.

Our oleos are strong and can take it – if – they receive proper maintenance. If they don’t get it – they’ll let
you down in one big hurry.

Sincerely yours,
AERONCA AIRCRAFT CORPORATION

/s/ W. B. Runyan, Jr.
Service and Operations Manager

WBR:rl

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