EASA AD CF-2023-75
Oxygen — Crew Oxygen System — Oxygen Fitting Production Installation Deficiency
Summary
Canadian Airworthiness Directive CF-2023-75 addresses a production installation deficiency in the crew oxygen system fittings on MHI RJ Aviation ULC model CL-600-2D15 and CL-600-2D24 aircraft, serial numbers 15476 through 15499. The directive mandates replacement of certain oxygen line bulkhead fittings and fitting adapters due to over-torque installation during production. This ensures the integrity of the oxygen system and prevents potential oxygen leakage affecting flight crew safety.
What Changed
CF-2023-75 introduces mandatory replacement of bulkhead fittings on oxygen lines of the mask stowage boxes within 4000 flight hours or 24 months, and replacement of fitting adapters on oxygen pressure gauges within 8800 flight hours or 48 months. These actions address a supplier quality issue where torque wrenches were out of calibration, causing over-torqued fittings during initial production installation.
Why It Matters
This directive is critical for aviation professionals to prevent oxygen leakage that could go undetected and compromise flight crew oxygen supply during operations. Operators and maintenance teams must ensure compliance to maintain airworthiness and crew safety. Failure to address this issue could lead to in-flight oxygen system failures, posing serious safety risks.
What To Do
Operators of affected MHI RJ Aviation ULC CL-600-2D15 and CL-600-2D24 aircraft must replace the bulkhead fittings on oxygen lines within 4000 flight hours or 24 months from December 12, 2023, whichever occurs first. Additionally, the fitting adapters on oxygen pressure gauges must be replaced within 8800 flight hours or 48 months from the same date. Compliance must follow the instructions in MHIRJ Service Bulletin 670BA-35-018 or later approved revisions.
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