AD 2021-13-02 Requires Installation Of An Insulation Blanket Assembly

The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777-300ER series airplanes.

This AD was prompted by a report that a production design change to certain insulation blankets inadvertently opened up leakage paths for halon and smoke to escape from the aft cargo compartment in the event of a fire. This AD requires installation of an insulation blanket assembly on top of existing insulation blankets in certain areas of the forward endwall in the aft cargo compartment. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective August 19, 2021.

Supplementary Information: The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain The Boeing Company Model 777-300ER series airplanes. The NPRM published in the Federal Register on December 29, 2020 (85 FR 85557).

The NPRM was prompted by report indicating that a production design change to certain insulation blankets inadvertently opened up leakage paths for halon and smoke to escape from the aft cargo compartment in the event of a fire.

In the NPRM, the FAA proposed to require installation of an insulation blanket assembly on top of existing insulation blankets in certain areas of the forward endwall in the aft cargo compartment. The FAA is issuing this AD to address increased leakage paths, which, in the event of a fire, could result in loss of fire suppressant in the cargo compartment, and could lead to an uncontained fire and subsequent loss of the airplane.

FMI: www.regulations.gov