EASA AD CF-2020-33
Navigation - Flight Management System - Wrong Magnetic Heading Displayed due to Outdated Magnetic Variation Tables
Summary
Canadian Airworthiness Directive CF-2020-33 addresses an issue affecting Bombardier Inc. model BD-100-1A10 aeroplanes, serial numbers 20003 through 20407, equipped with FMC-5000 Flight Management Computers. The directive identifies that outdated magnetic variation tables in the Flight Management System can cause incorrect magnetic heading displays on flight instruments. This can compromise navigation accuracy and safety during flight operations.
What Changed
CF-2020-33 introduces a requirement to update the Airplane Flight Manuals (AFMs) with revised limitations related to the Flight Management System. The update specifically involves incorporating Transport Canada Civil Aviation approved revisions to Chapter 02 – Limitations – Systems Limitations – Flight Management System. This is a new directive mandating these changes to address the unsafe condition caused by obsolete magnetic variation data.
Why It Matters
This directive is critical for aviation professionals because inaccurate magnetic heading information can lead to navigation errors, potentially placing aircraft outside protected flight paths and increasing the risk of terrain or obstacle conflicts. Operators and maintenance teams must ensure compliance to maintain flight safety and regulatory adherence. Flight crews need to be informed of the AFM changes to operate the aircraft safely under the updated system limitations.
What To Do
Operators of affected Bombardier BD-100-1A10 aircraft must amend their AFMs by incorporating the specified revisions to the Flight Management System limitations within 60 days of the directive's effective date. After updating the AFMs, all flight crews must be briefed on the changes and operate the aircraft accordingly. Compliance with Canadian Aviation Regulation 605.84 regarding Airworthiness Directives is mandatory before conducting take-offs.
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