Page 7 - Aeronca 7A Interactive Service Manual

PROPELLER LIMITS
Static R.P.M. at full throttle setting not more than 2200 R.P.M., not less than 2010 R.P.M.

DIAMETER
Not more than 72 inches.
Not less than 70 inches.

EXPORT OR FOREIGN

CAA has approved left windows as emergency exit. Defined in C.A.R. 04.462 for export particularly
Canada. Tests have been run and it has been found that by pushing from the inside, either one or both of
the windows may be removed in an emergency and only a nominal amount of pressure is required.

WING FRAME

The wing frame consists of laminated spruce spars reinforced at the butt and strut attachments with three
ply spruce pads. All ribs are one piece hydro-formed aluminum reinforced at the spar openings bottom,
with spot welded aluminum gussets. The butt and inner aileron bay ribs are .040 – 52 S ½ H. aluminum
alloy, and the main, tip and aileron bay ribs are .020 – 52 ½ H. aluminum alloy.

Spar butt attachment and strut attachment fitting holes are reinforced with micarta bushings pressed and
glued into the spar blank. Kem wood primer is applied to the spar as a protective coating, and should be
reapplied to any exposed wood after splicing or repairs. Methods of splicing and repair are covered in Civil
Aeronautics Manual 18.

Spar butt fittings are X4130 steel, clevis type. Damaged or worn spar butt fittings should never be welded
or bushed but should be replaced complete and may be ordered by giving the number shown on the
accompanying drawing.

The wings are attached to the fuselage with AN6-24 bolt, AN310-6 nut, rear spar, and AN5-14 bolt,
AN310-5 nut, front spar.

These bolts pass through the spar butt clevis type fittings and fuselage spar attachment fittings. The spar
butt attachment fittings are designed to fit snugly to the fuselage fittings and should not be bushed or
shimmed. The front spar strut attachment fittings include tie down rings as an integral part of the fittings.
The rear strut is attached with a bolt through the spar and the strut upper end fitting.

Bellcrank and bracket assembly is cast aluminum. The counter-balanced bellcrank and ball bearings
provide ease of aileron control and is another new feature incorporated in the control system to insure
smooth positive control action.

Two .125 – 24 St Alclad aluminum brackets bolted to the rear spar support the aileron in conjunction with
the aileron bellcrank assembly, which incorporates an aileron bearing support on the bellcrank bracket.

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