Airworthiness Directive · Amendment 39-14710 · Boeing Model 747-200B, 747-200C, 747-200F, 747-300, and 747SR Series Airplanes
Boeing Model 747-200B, 747-200C, 747-200F, 747-300, and 747SR Series Airplanes
This AD applies to Boeing Model 747-200B, 747-200C, 747-200F, 747-300, and 747SR series airplanes, certificated in any category; as identified in Boeing Special Attention Service Bulletin 747-54-2223, dated January 26, 2006.
The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 747-200B, 747-200C, 747-200F, 747-300, and 747SR series airplanes. This AD requires doing repetitive inspections of engine struts 1 through 4, as applicable, for heat discoloration, cracking, buckling, or wrinkling. This AD also requires doing a conductivity test to detect the extent of the heat damage and an inspection to detect cracking of the heat-discolored, buckled, or wrinkled area; and repair; if necessary. This AD results from reports of heat damage and cracking of the skin and internal structure adjacent to and aft of the precooler exhaust vent on several engine struts. We are issuing this AD to detect and correct cracking, buckling, wrinkling, or heat damage of the skin and internal structure of the engine struts, which could result in extensive damage to the engine struts and consequent possible separation of an engine from the airplane during flight.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
The term “service bulletin,” as used in this AD, means the Accomplishment Instructions of Boeing Special Attention Service Bulletin 747-54-2223, dated January 26, 2006.
Within 18 months after the effective date of this AD, do a detailed inspection of engine struts 1 through 4, as applicable, for heat discoloration, cracking, buckling, or wrinkling, in accordance with the service bulletin. Repeat the detailed inspection thereafter at intervals not to exceed 18 months.
If any heat discoloration, buckling, or wrinkling is found during any detailed inspection required by paragraph (g) of this AD, before further flight, do a conductivity test to detect the extent of the heat damage and a penetrant inspection or high frequency eddy current inspection to detect cracking of the heat-discolored, buckled, or wrinkled area, in accordance with the service bulletin.
(1) If the conductivity test results are within the limits specified in the service bulletin and no cracking is detected, before further flight, repair any buckled or wrinkled area using a method approved in accordance with the procedures specified in paragraph (j) of this AD. Heat discoloration does not need to be repaired if the conductivity test results of the heat-discolored area are within the specified limits in the service bulletin.
(2) If the conductivity test results are outside the limits specified in the service bulletin or if any cracking is detected, before further flight, repair any cracking, heat discoloration, or buckled or wrinkled area using a method approved in accordance with the procedures specified in paragraph (j) of this AD.
(i) If any cracking is found during any detailed inspection required by paragraph (g) of this AD, before further flight, repair the cracking using a method approved in accordance with the procedures specified in paragraph (j) of this AD.
