AD 2013-11-04 Airworthiness Directives; The Boeing Company Airplanes

Models named: 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to The Boeing Company airplanes, certificated in any category, identified in paragraphs (c)(1), (c)(2), and (c)(3) of this AD. (1) Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes, as identified in Boeing Special Attention Service Bulletin 747-25-3381, Revision 1, dated May 17, 2012. (2) Model 767-200, -300, -300F, and -400ER series airplanes, as identified in Boeing Special Attention Service Bulletin 767-25-0381, Revision 1, dated September 17, 2012. (3) Model 777-200, -200LR, -300, and -300ER series airplanes, as identified in Boeing Special Attention Service Bulletin 777-25-0362, dated August 19, 2010.

Comply with this AD within the compliance times specified, unless already done.

Within 72 months after the effective date of this AD, do the actions specified in paragraph (g)(1), (g)(2), or (g)(3) of this AD, as applicable. (1) For Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes: Replace the BMS 8-39 urethane foam seals (including doing a general visual inspection of the airplane sidewalls for air baffles, and of the BMS 8-39 urethane foam for penetrations (e.g., wire penetrations)) with BMS 8-371 insulation foam or BMS 1-68 silicone foam rubber seals, as applicable, in accordance with the Accomplishment Instructions and Appendix A, as applicable, of Boeing Special Attention Service Bulletin 747-25-3381, Revision 1, dated May 17, 2012. (2) For Model 767-200, -300, -300F, and -400ER series airplanes: Perform a general visual inspection for the presence of BMS 8-39 urethane foam, cover the BMS 8-39 foam with cargo liner joint sealing tape in certain areas, replace certain BMS 8-39 foam pads with Nomex felt in certain areas, and replace BMS 8-39 urethane foam seals with BMS 8-371 insulation foam or BMS 1-68 silicone foam rubber seals, as applicable, in accordance with the Accomplishment Instructions and Appendix A, as applicable, of Boeing Special Attention Service Bulletin 767-25-0381, Revision 1, dated September 17, 2012. (3) For Model 777-200, -200LR, -300, and -300ER series airplanes: Replace BMS 8-39 urethane foam seals with BMS 1-68 silicone foam rubber seals in the forward and aft cargo compartments of the airplane, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 777-25-0362, dated August 19, 2010.

This AD was prompted by reports of burned Boeing Material Specification (BMS) 8-39 urethane foam, and a report from the airplane manufacturer indicating that airplanes were assembled, throughout various areas of the airplane (including flight deck and cargo compartments), with seals made of BMS 8-39 urethane foam, a material with fire-retardant properties that deteriorate with age. We are issuing this AD to prevent the failure of urethane seals to maintain sufficient Halon concentrations in the cargo compartments to extinguish or contain fire or smoke, and to prevent penetration of fire or smoke in areas of the airplane that are difficult to access for fire and smoke detection or suppression.

None.