49-15-01 AERONCA: Applies to All Models 11AC, S11AC and 11BC Aircraft.
To be accomplished not later than July 1, 1949.
In order to prevent the seat belt anchorage from failing during crash landings, it has been found necessary to modify the seat installation as follows:
1. If there is no need for an adjustable seat, the rear sliding lugs on each side of the seat should be bolted to the slide tube using 3/16- or 1/4-inch diameter AN bolts.
2. If the seat is to remain adjustable, two 1/8 7 x 19 steel snare cables looped around each end of the seat frame cross tube and the lower end of the vertical slide fuselage tube located aft of the seat should be installed so that they will be taut with the seat in the most forward position. Any approved type cable clamp may be used for joining the ends of the cable.
(Aeronca Helps and Hints No. 42 covers this same subject.)
This supersedes AD 49-13-01.