EASA AD CF-2023-76
Electrical Power — Air Driven Generator (ADG) — Locking Cam Screw and Cam Nut Assembly Production Installation Deficiency
Summary
The Electrical Power — Air Driven Generator (ADG) — Locking Cam Screw and Cam Nut Assembly Production Installation Deficiency is a Canadian Airworthiness Directive (CF-2023-76) issued by Transport Canada. It applies to Mitsubishi Heavy Industries RJ Aviation ULC (MHIRJ) CL-600-2D15 and CL-600-2D24 aircraft with serial numbers 15476 to 15499. The directive addresses a production installation defect involving the locking cam screw and cam nut assembly of the ADG mechanism.
What Changed
This new directive requires the replacement of the locking cam screw and cam nut assembly on the ADG due to a supplier quality issue where torque wrenches were miscalibrated, causing over-torque during initial installation. The over-torque condition could lead to failure of the screw and cam, potentially resulting in loss of ADG locking mechanism functionality during landing.
Why It Matters
This directive is critical for aviation professionals because failure of the ADG locking mechanism could compromise the electrical power system during critical phases of flight, such as landing. Operators, maintenance organizations, and compliance teams must ensure timely corrective action to maintain aircraft safety and regulatory compliance.
What To Do
Operators of affected MHIRJ CL-600-2D15 and CL-600-2D24 aircraft must replace the locking cam screw and cam nut assembly within 2900 flight hours or 18 months from the directive's effective date, whichever occurs first. The replacement must follow the procedures specified in section 2.B. of revision A of MHIRJ Service Bulletin 670BA-24-040 dated November 7, 2023, or any later approved revision. Aircraft already modified per the initial issue of the service bulletin dated September 26, 2023, comply with this directive.
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