Airworthiness Directive · Amendment 39-21869 · Equipment/furnishings
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 747-400, -400D, and -400F series airplanes, certificated in any category, identified as Group 11, Configuration 2; Group 13 and 14, Configuration 4; and Group 16, 17, and 19, Configuration 5, in Boeing Special Attention Service Bulletin 747-25-3381, Revision 3, dated February 19, 2021.
The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-400, -400D, and -400F series airplanes. This AD was prompted by reports of burned Boeing Material Specification (BMS) 8-39 urethane foam, and a report from the airplane manufacturer that airplanes were assembled with seals throughout various areas of the airplane (including flight deck and cargo compartments) made of BMS 8-39 urethane foam, a material with fire- retardant properties that deteriorate with age. This AD requires replacing the system tube/wire seals made of BMS 8-39 urethane foam in certain areas of the airplane. The FAA is issuing this AD to address the unsafe condition on these products.
Within 72 months after the effective date of this AD: Replace the BMS 8-39 urethane foam seals in the forward cargo compartment system tube/wire (including doing a general visual inspection of the foam for any tube or wire penetrations and sealing any penetrations that go through the insulation blankets) with BMS 1-68 silicone foam rubber seals, as applicable, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 747-25-3381, Revision 3, dated February 19, 2021.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
