AD 2020-26-08 Was Prompted By Reports Of Damage To The Inner Fixed Structure (IFS) Forward Upper Fire Seal

The FAA is adopting a new airworthiness directive (AD) for The Boeing Company Model 787-8, 787-9, and 787-10 airplanes powered by Rolls Royce Trent 1000 engines.

This AD was prompted by reports of damage to the inner fixed structure (IFS) forward upper fire seal and damage to thermal insulation blankets in the forward upper area of the thrust reverser (TR). This AD requires repetitive inspections of the IFS forward upper fire seal and thermal insulation blankets in the forward upper area of the TR for damage and applicable on-condition actions. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective January 27, 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 The Boeing Company Model 787-8, 787-9, and 787-10 airplanes powered by Rolls Royce Trent 1000 engines. The NPRM published in the Federal Register on June 16, 2020 (85 FR 36352). The NPRM was prompted by reports of damage to the IFS forward upper fire seal and damage to thermal insulation blankets in the forward upper area of the TR. The NPRM proposed to require repetitive inspections of the IFS forward upper fire seal and thermal insulation blankets in the forward upper area of the TR for damage and applicable on-condition actions.

The FAA is issuing this AD to address damage to the IFS forward upper fire seal and the thermal insulation blankets of the TR due to airflow through structural gapping that could occur at the interface between the leading edge of the IFS and the engine splitter structure during flight. Failure of the IFS forward upper fire seal could cause the loss of seal pressurization and degrade the ability to detect and extinguish an engine fire, resulting in an uncontrolled fire. Damage to the TR insulation blanket could result in thermal damage to the TR inner wall, the subsequent release of engine exhaust components, and consequent damage to critical areas of the airplane. Furthermore, damage to the TR inner wall and IFS forward upper fire seal could compromise the integrity of the firewall and its ability to contain an engine fire, resulting in an uncontrolled fire.

FMI: www.regulations.gov