Airworthiness Directive · Amendment 39-15309 · Boeing Model 747-200B, 747-300, 747-400, 747-400D, and 747-400F Series Airplanes Equipped with General Electric CF6-80C2 Engines
Boeing Model 747-200B, 747-300, 747-400, 747-400D, and 747-400F Series Airplanes Equipped with General Electric CF6-80C2 Engines
This AD applies to Boeing Model 747-200B, 747-300, 747-400, 747-400D, and 747-400F series airplanes, certificated in any category, equipped with General Electric CF6-80C2 engines.
The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 747-200B, 747-300, 747-400, 747-400D, and 747-400F series airplanes. This AD requires repetitive inspections of the left- and right-hand flipper door assemblies of the engine core cowls for migrated pins and damaged flipper doors, and corrective actions if necessary. Modification of the hinge assemblies terminates the repetitive inspections. This AD results from two reports of missing flipper doors for the engine core cowls. We are issuing this AD to detect and correct migrated hinge pins and damaged flipper doors, which could allow the flipper door to fall off, resulting in the potential for an engine fire to propagate into the flammable leakage zone of the strut and for the amount of fire extinguishing agent reaching the fire to be diluted, and subsequent uncontained fire in the engine strut.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 24 months after the effective date of this AD: Do a general visual inspection for migrated hinge pins and damaged flipper doors of the left- and right-hand flipper door assemblies of the engine core cowls, and do all applicable corrective actions, by accomplishing all the actions specified in the Accomplishment Instructions of Boeing Special Attention Service Bulletin 747-71-2310, dated October 13, 2005. Do all applicable corrective actions before further flight. Repeat the inspection thereafter at intervals not to exceed 18 months for that flipper door assembly, until doing the actions specified in paragraph (g) of this AD.
Note 1: Boeing Special Attention Service Bulletin 747-71-2310, dated October 13, 2005, refers to Rohr Service Bulletin TBC/80C2-NAC-71-035, dated October 10, 2005, as an additional source of service information for accomplishing the actions specified in paragraph (f) of this AD.
Accomplishing the inspection and applicable modification of a hinge assembly of a flipper door assembly of the engine core cowl in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 747-71-2310, dated October 13, 2005; or Rohr Service Bulletin TBC/80C2-NAC-71-035, dated October 10, 2005; terminates the repetitive inspection requirements of this AD for that hinge assembly.
As of the effective date of this AD, no person may install, on any airplane, a hinge assembly, part number 224-2335-69, for the flipper door of the engine core cowl unless it has been modified in accordance with the requirements of paragraph (g) of this AD.
