66-14-01: Wing Main Spar

66-14-01 AERO COMMANDER (SNOW): Amdt. 39-246 Part 39 Federal Register June 3, 1966. Applies to Models S-2A, S-2B, S-2C, and 600 S-2C Airplanes. Compliance required as indicated, unless already accomplished. To prevent fatigue cracks in the lower spar cap of the wing main spar, accomplish the following: (a) For Model S-2A airplanes with 1,400 or more hours' time in service on the effective date of this AD - (1) Comply with (k) within the next 100 hours' time in service and comply with (l) within the next 1,500 hours' time in service after complying with (k); or (2) Comply with (l) within the next 100 hours' time in service. (b) For Model S-2A airplanes with less than 1,400 hours' time in service on the effective date of this AD - (1) Comply with (k) before the accumulation of 1,500 hours' time in service and comply with (l) within the next 1,500 hours' time in service after complying with (k); or (2) Comply with (l) before the accumulation of 1,500 hours' time in service. (c) For Models S-2B and S-2C airplanes, Serial Number 1189 and below, powered by 450 hp. engines, with 900 or more hours' time in service on the effective date of this AD - (1) Comply with (k) within the next 100 hours' time in service and comply with (l) within the next 1,000 hours' time in service after complying with (k); or (2) Comply with (l) within the next 100 hours' time in service. (d) For Models S-2B and S-2C airplanes, Serial Number 1189 and below, powered by 450 hp. engines, with less than 900 hours' time in service on the effective date of this AD - (1) Comply with (k) before the accumulation of 1,000 hours' time in service and comply with (l) within the next 1,000 hours' time in service after complying with (k); or (2) Comply with (l) before the accumulation of 1,000 hours' time in service. (e) For Model S-2C airplanes, Serial Numbers 1190 through 1231, powered by 450 hp. engines, with 900 or more hours' time in service on the effective date of this AD, comply with (l) within the next 100 hours' time in service. (f) For Model S-2C airplanes, Serial Numbers 1190 through 1231, powered by 450 hp. engines, with less than 900 hours' time in service on the effective date of this AD, comply with (l) before the accumulation of 1,000 hours' time in service. (g) For Models S-2C and 600 S-2C airplanes, Serial Number 1189 and below, powered by 600 hp. engines, with 600 or more hours' time in service on the effective date of this AD - (1) Comply with (k) within the next 100 hours' time in service and comply with (l) within the next 700 hours' time in service after complying with (k); or (2) Comply with (l) within the next 100 hours' time in service. (h) For Models S-2C and 600 S-2C airplanes, Serial Number 1189 and below, powered by 600 hp. engines, with less than 600 hours' time in service on the effective date of this AD - (1) Comply with (k) before the accumulation of 700 hours' time in service and comply with (l) within the next 700 hours' time in service after complying with (k); or (2) Comply with (l) before the accumulation of 700 hours' time in service. (i) For Models S-2C and 600 S-2C airplanes, Serial Numbers 1190 through 1231, powered by 600 hp. engines, with 600 or more hours' time in service on the effective date of this AD, comply with (l) within the next 100 hours' time in service. (j) For Models S-2C and 600 S-2C airplanes, Serial Numbers 1190 through 1231, powered by 600 hp. engines, with less than 600 hours' time in service on the effective date of this AD, comply with (l) before the accumulation of 700 hours' time in service. (k) Install modified wing center splice in accordance with Snow Service Letter No. 29 or an equivalent approved by the Chief, Engineering and Manufacturing Branch, FAA Southwest Region. (l) Install wing lower steel spar caps in accordance with Snow Drawing No. 5-1089, Revision D, or an equivalent approved by the Chief, Engineering and Manufacturing Branch, FAA Southwest Region. (Snow Service Letter No. 36 pertains to this subject.) This directive effective July 5, 1966.