AD 2021-24-02 Prompted By Reports Indicating Incidents Of Wires Chafing

The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model MD-11 and MD-11F airplanes.

This AD was prompted by reports indicating incidents of wires chafing against the inboard upper corner of the observer station circuit breaker panel. This AD requires, depending on airplane configuration, doing a general visual inspection of the right observer station upper main circuit breaker panel and wiring for certain missing parts; doing an inspection of the right observer station upper main circuit breaker panel to determine if a certain bracket part number is installed; doing a general visual inspection of certain wire assemblies for any damage; modifying the observer station upper main circuit breaker panel; and applicable on-condition actions. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective February 1, 2022.

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 all The Boeing Company Model MD-11 and MD-11F airplanes.

The NPRM published in the Federal Register on August 18, 2021 (86 FR 46167). The NPRM was prompted by reports indicating incidents of wires chafing against the inboard upper corner of the observer station circuit breaker panel. In the NPRM, the FAA proposed to  require, depending on airplane configuration, doing a general visual inspection of the right observer station upper main circuit breaker panel and wiring for certain missing parts; doing an inspection of the right observer station upper main circuit breaker panel to determine if a certain bracket part number is installed; doing a general visual inspection of certain wire assemblies for any damage; modifying the observer station upper main circuit breaker panel; and applicable on-condition actions. The FAA is issuing this AD to address wire chafing and arcing on the panel, which could cause damage to equipment, and result in loss of electrical power and a possible in-flight fire.

FMI: www.regulations.gov