Page 6 - Aeronca 7A Interactive Service Manual

RIGGING INSTRUCTIONS

LEVELING
Level in fore and aft direction by supporting tail on stand and placing bubble level on front window sill or
any portion of cabin floor. When bubble is centered in level, the aircraft is longitudinally level.

WING RIGGING
DIHEDRAL

The plus 2° angle of dihedral is fixed by the length of the front strut.

ANGLE OF INCIDENCE

The angle of incidence, which is plus 1° at the leading edge over the trailing edge through the five foot
chord of the wing, is fixed in the manufacture of the airplane at the wing root fittings on the fuselage.

The angle of incidence at the rib nearest the strut point attachment fitting of the wing may be corrected
to the corresponding angle of incidence at the root, by adjusting the screw adjustment at the lower end
of the rear strut where it attaches to the front strut.

RIGGING
For rigging purposes a bubble level should be laid along the bottom of the butt rib between the spars. The
level may be shimmed with a small block on the leading edge end of the level until bubble is centered. Tape
the shim in place and move level to the rib adjacent to the strut attaching points, parallel with the rib and
between the spars. This will offer a reference means of alignment. By adjusting rear strut lower end fitting
until bubble is centered in level, the proper angle of incidence along entire wing will be accomplished.

ADJUSTMENT

If after flight test the airplane has a tendency toward wing heaviness, the necessary wash in or wash out
may be secured by adjusting the rear strut at its lower attachment point.

CAUTION: Only a CAA licensed aircraft mechanic should attempt the assembly and
rigging of wings and struts.

CENTER OF GRAVITY LIMITATIONS

Datum line wing leading edge
M.A.C. 58.84 inches
Leading Edge M.A.C. plus .28 inches
Center of gravity range plus 10.9, (18.0% M.A.C.) most forward, plus 21.5 (36.0% M.A.C.) most rearward.

AIRSPEED LIMITATIONS
Do not exceed 129 M.P.H. true indicated airspeed at any time. This figure is derived from stress analysis
and flight testing at the factory and has been established with a reasonable margin of safety.

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