51-08-03 TEMCO: Applies to Models GC-1A and GC-1B Aircraft - All Serial Numbers.
Compliance required at next periodic inspection but not later than May 1, 1951.
Inspect the horizontal stabilizer front spar attachment to the fuselage bulkhead for looseness. First remove all fairing or interfering items. Support the horizontal stabilizers on the fuselage so that their position cannot change; remove the four AN 3 bolts which attach the front stabilizer spar to the fuselage bulkhead. If there is no deformation or elongation of these bolt holes and if the holes in the stabilizer spar and the fuselage bulkhead are in correct alinement the AN 3 bolts should be reinstalled, torquing them to 25-30 inch-pounds.
If there is deformation or elongation of the attach bolt holes, a repair can be accomplished by reaming these 3/16-inch holes to 1/4-inch diameter with the stabilizers firmly blocked in the proper position with the fuselage. The AN 3 bolts, nuts, and washers are to be replaced with AN 4 bolts, nuts, and washers, and they should be torqued to 80-90 inch-pounds in reassembling the stabilizer front spar attachment. The empennage and fairing which were removed for this inspection and repair are then reassembled on the airplane.
If the AN 3 attachment bolts are retained, this inspection should be repeated at each periodic or annual inspection. If the AN 4 attachment bolts are installed, only the normal inspections of this attachment need be made.