AD 59-04-01

59-04-01 AERO COMMANDER: Applies to Models 500, 560, 560A, 560E, 680, 680E, and 720, Serial Numbers 151 Through 710 Inclusive.

Compliance required as indicated.

Rivets have been inadvertently omitted, at the factory, from the rear spars of the vertical and horizontal stabilizers on some of the aircraft listed above. The rivets involved are the four web splice rivets on the vertical stabilizer rear spar approximately 4 1/2 inches below the center hinge bracket, and either one or two of the normal three web splice rivets on each horizontal stabilizer rear spar just inboard of the center hinge bracket as shown in Figures 1 and 2 respectively. (NOTE: Figure 2 shows four rivets in the reworked web splice. In the normal web splice, which does not require rework, there is one rivet on the centerline and one each through the top and bottom spar cap.)

An inspection should be made immediately to determine if any of the above rivets are missing. If any or all of these rivets are missing the following rework should be accomplished as soon as possible but not later than March 31, 1959.

(1) Vertical Stabilizer - Rear Spar - In the locations shown in Figure 1 drill four holes using a number 20 drill bit and install four cherry rivets, P/N CR163-5-4.

(2) Horizontal Stabilizer - Rear Spar - In the locations shown in Figure 2 install two CR163-5-4 rivets on each stabilizer. In the event the spar web lap extends less than 1/2-inch inboard of the forward flange on the center hinge bracket (see Figure 2) the Service Department, Aero Design and Engineering Company, Bethany, Oklahoma, should be contacted for instructions for installation of a spar web doubler.

(Aero Design and Engineering Company Service Bulletin No. 50, dated December 17, 1958, also covers this subject.)

Service Bulletin No. 50