AD 2022-26-04 Prompted By A Report Of An Oxygen-Fed Ground Fire Event...

The FAA is adopting a new airworthiness directive (AD) for all MHI RJ Aviation ULC Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. 

This AD was prompted by a report of an oxygen-fed ground fire event potentially caused by electrical arcing from a faulty surround light wire on the third crew member's (observer) oxygen mask. This AD was also prompted by the determination that additional inspections and a bracket trim are needed to address the unsafe condition. This AD requires an inspection for discrepancies of the observer's oxygen mask stowage box and stowage compartment, oxygen hose connections and routing, and the associated electrical harness, and corrective actions if necessary; and modifying the oxygen mask flexible lamp harness, mounting plate, and compartment panel, including rerouting the electrical harness and applying protective sealant. This AD also requires an inspection for correct installation of the flexible lamp assembly; trimming and reidentifying a bracket; and for certain airplanes, an inspection for damage of the wire harness assembly; and applicable corrective actions. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective February 2, 2023.

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 MHI RJ Aviation ULC Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. The NPRM published in the Federal Register on February 25, 2022 (87 FR 10752). The NPRM was prompted by AD CF-2021-32, dated September 17, 2021, issued by Transport Canada, which is the aviation authority for Canada (Transport Canada AD CF-2021-32). Transport Canada AD CF-2021-32 states that an oxygen-fed ground fire event was potentially caused by electrical arcing from a faulty surround light wire on the third crew member's (observer) oxygen mask. An investigation determined that the oxygen supply hose connecting to the rear of the observer oxygen mask box assembly could be subject to chafing damage.

In the NPRM, the FAA proposed to require an inspection for discrepancies of the observer's oxygen mask stowage box and storage compartment, oxygen hose connections and routing, and the associated electrical harness, and corrective actions if necessary; and modifying the oxygen mask flexible lamp harness, mounting plate, and compartment panel, including rerouting the electrical harness and applying protective sealant.

The FAA issued a supplemental notice of proposed rulemaking (SNPRM) to amend 14 CFR part 39 by adding an AD that would apply to all MHI RJ Aviation ULC Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. The SNPRM published in the Federal Register on October 21, 2022 (87 FR 63970). The SNPRM was prompted by Transport Canada AD CF-2021-32R1, dated July 25, 2022 (also referred to as the MCAI). The MCAI states that since Transport Canada AD CF-2021-32 was issued, an operator reporting a fouling condition between the power feed wires for the stowage box light strip and an existing aluminum bracket in the entrance monument mask stowage compartment. The SNPRM was also prompted by the determination that additional inspections and a bracket trim are needed to address the unsafe condition. In the SNPRM, the FAA again proposed to require an inspection for discrepancies of the observer's oxygen mask stowage box and storage compartment, oxygen hose connections and routing, and the associated electrical harness, and corrective actions if necessary; and modifying the oxygen mask flexible lamp harness, mounting plate, and compartment panel, including rerouting the electrical harness and applying protective sealant. In the SNPRM, the FAA further proposed to require an inspection for correct installation of the flexible lamp assembly; trimming and reidentifying a bracket; and for certain airplanes, an inspection for damage of the wire harness assembly; and applicable corrective actions. The FAA is issuing this AD to address possible damage to the observer oxygen mask supply hoses and a potential for an oxygen-fed fire in the vicinity of the observer oxygen mask storage compartment.

You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2022-0141.

FMI: www.regulations.gov