46-23-04: Addition of Rivets in Wing Skin

46-23-04 GLOBE: (Was Mandatory Note 1 of AD-766-5.) Applies to Models GC-1A, GC-1B Aircraft Serial Numbers 33 to 54 Inclusive, Plus 54, 56, 57, 58, 60, 61, and 64. Due to an inadvertent error in the manufacture of these airplanes, the following reinforcement of the rivet seam attaching the upper skin of the outer wing panels to the main spar is to be accomplished as follows. In lieu of immediate accomplishment, the maximum weight may be reduced from 1,570 pounds to 1,490 pounds. This may require elimination of the baggage allowance. In any case, the reinforcement outlined below must be accomplished not later than September 1, 1946. After completion of the reinforcement, the placard may be removed and the weight increased to the maximum specified in the Aircraft Specification. In the length of the seam from 1 1/2-inches to 4 3/4-inches outboard of the outer panel attachment bolt, the number of rivets should be increased to not less than five. Since the heads of the bolt through the end fitting of the spar cause interference at the originally intended spacing, the rivets may be spaced unequally, but the minimum spacing may not be less than 3/8-inch. In the length of the seam from 4 3/4-inches to 11 1/2-inches outboard of the outer panel attachment bolt, sufficient rivets should be added to make the spacing approximately 3/8-inch. The added rivets may be either Cherry CR163-4-10 or AN 456-AD4. (Globe Customer Service Maintenance Bulletin No. 1 covers this same subject.)