58-25-01: Elevator Torque Tube

58-25-01 CONVAIR: Applies to All Model 240 Series Aircraft. Compliance required as indicated. During a recent inspection of a Convair 240 aircraft, six rivets out of the total of eight attaching P/N 3540311 to the left-hand elevator torque tube were found sheared. In order to assure airworthiness of the aircraft, the following action is to be taken. (NOTE: A previous Convair service bulletin, issued as a result of a number of reports of rivet failures in this area, recommends replacement of the original rivets with steel rivets. This replacement had not been accomplished in the case mentioned above.) 1. Compliance required as soon as possible but not later than the next 25 hours of operation and every 300 hours thereafter until modified in accordance with item 2. Inspect the 240-3540311 flange fitting attachment to the elevator torque tube, left and right side, for looseness and sheared rivets. If looseness or any sheared rivets are found, compliance with item 2 required prior to further flight. 2. Compliance required not later than the next major overhaul. Replace the eight AN 470-D8 rivets attaching the flange fitting P/N 240-3540311 to the torque tube, left and right side, with eight Q4311-C9-12 steel, drilled shank, rivets or equivalent. Eight close tolerance corrosion resistant steel bolts or four close tolerance corrosion resistant steel bolts and four oversized rivets are acceptable equivalents. (Convair Service Bulletin 240-384 dated October 25, 1950, covers this same subject.)