EASA AD 2026-0163
Navigation – GLU-2100 Global Navigation Satellite System Clock Oscillator – Operational Limitation
Summary
EASA Airworthiness Directive 2026-0163 is an operational limitation directive affecting Airbus A350-941 and A350-1041 aeroplanes. It addresses issues with the GLU-2100 Global Navigation Satellite System Clock Oscillator, specifically certain units with untested oscillators that may cause erroneous position information. The directive prohibits operation and installation of affected GLU-2100 units unless modified according to Collins Aerospace instructions.
What Changed
This new directive introduces an operational limitation prohibiting the use and installation of specific GLU-2100 units with certain serial numbers on Airbus A350 aircraft. It requires identification and modification of affected parts as per Collins Aerospace Vendor Service Bulletin GLU-2100-34-B. No affected parts are currently installed on any aircraft, so no retroactive compliance time is required.
Why It Matters
This directive is critical for aviation professionals because the affected GLU-2100 units can cause inaccurate aircraft position data without warning, potentially compromising flight safety. Operators and maintenance teams must ensure that no affected parts are installed or operated to maintain compliance and airworthiness. It also impacts maintenance planning and parts inventory control to avoid installation of non-compliant units.
What To Do
From 19 August 2026, operators must not operate any Airbus A350 aircraft with an affected GLU-2100 unit installed and must not install any affected parts. Replacement of affected parts with compliant units following the aircraft maintenance manual is acceptable to meet the directive's requirements. Stakeholders should refer to Collins Aerospace VSB GLU-2100-34-B Revision 1 for modification instructions.
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