84-09-03: Fuselage Upper Longerons

84-09-03 AYRES CORPORATION: Amendment 39-4916. Applies to Model S2R-R1820 (S/N's R1820-001DC through S/N R1820-031DC) airplanes certificated in any category. Compliance: Required as indicated, unless already accomplished. To prevent failure of the fuselage upper longerons, accomplish the following: (a) Before further flight and thereafter at intervals not to exceed ten (10) hours time-in-service, visually check the forward fuselage upper longerons for cracks in accordance with the following: (1) Remove the fuselage side skins located between the wing upper surface and the hopper to obtain access to the upper longerons from the firewall to the cockpit. (2) Check the longerons in the following areas: (Same as shown in Figure 1 of Ayres Corporation Service Bulletin No. SB-AG-16 dated April 1, 1984.) (i) Area between upper engine mount and first hopper attachment bracket. (ii) Each vertical and diagonal tube intersection at the upper longeron.(iii) Each hopper attachment bracket. This check may be accomplished by the holder of at least a private pilot certificate issued under Part 61 of the Federal Aviation Regulations on any airplane owned or operated by that person. (b) If cracks are found as a result of any check required by paragraph (a), prior to further flight, install the tubular split-sleeve modification (P/N CK-AG-19) on both upper longerons in accordance with Ayres Corporation Service Bulletin No. SB-AG-16, dated April 1, 1984. (c) Within one hundred (100) hours time-in-service after the effective date of this AD, install the tubular split-sleeve modification (P/N CK-AG-19) on both upper longerons in accordance with Ayres Corporation Service Bulletin No. SB-AG-16, dated April 1, 1984. (d) The checks required by paragraph (a) may be discontinued when the tubular split-sleeve modification (P/N CK-AG-19) is incorporated. (e) Airplanes may be flown in accordance with FAR 21.197 to a location where the modification required by this AD may be accomplished. (f) An equivalent means of compliance with this AD may be used if approved by the Manager, Atlanta Aircraft Certification Office, FAA Central Region, telephone (404) 763-7428. This airworthiness directive becomes effective September 21, 1984, as to all persons except those persons to whom it was made immediately effective by priority letter AD 84-09-03, issued May 7, 1984.