74-08-12 BELL: Amendment 39-1815. Applies to Model 206A and 206B helicopters, serial numbers 1 through 944, certificated in all categories.
Compliance required within 50 hours time in service after the effective date of this A.D., unless already accomplished within the last 50 hours time in service, and thereafter at intervals not to exceed 100 hours time in service from the last inspection.
To detect loose rivets in the tail boom skin splice from Station 300 to Station 341 on the left-hand side of the boom and cracked tail boom skin in the same area, accomplish the following:
(a) Inspect visually the rivets for looseness or working in the skin splice and inspect the tail boom skin for cracks using a three power or higher magnifying glass.
(b) Replace loose rivets with AN470AD5-2 or CR2249-5-2 or equivalent rivets before further flight.
(c) Replace cracked tail booms before further flight with a serviceable tail boom in accordance with Section VIII of the Model 206A/B Maintenance and Overhaul Instructions or repair cracked tail booms in accordance with FAA or FAA DER approved repair data.
(d) The repetitive inspections are still applicable for the noted helicopters after replacement of loose rivets or repair of cracked booms.
(Bell Helicopter Co. Service Bulletin No. 206-01-73-4, Revision B, dated October 16, 1973 pertains to this subject.)
This amendment becomes effective May 14, 1974.