TRIG AVIONICS Ltd. — Navigation — Transponders — Inspection / Modification
- Published
- Effective
- Deadline
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Operators must inspect affected transponder installations within three months of 27 November 2018 to confirm conventional orientation. If installations are non-conventional, the transponder must be removed before the next flight and sent to Trig Avionics for modification. From the effective date, no affected transponder may be installed unless the installation is conventional. Compliance with the specified Trig Avionics Service Bulletins is required.
Summary
EASA Airworthiness Directive 2018-0247 is an official regulatory document addressing inspection and modification requirements for TRIG AVIONICS Ltd. TT31, AXP340, and KT74 Mode S transponders installed on various Part 23 aeroplanes and Part 27 helicopters. The directive applies to specific serial numbers and part numbers of these transponders, including those supplied by Avidyne Corporation and BendixKing / Honeywell International. It mandates inspections and potential modifications to ensure compliance with crash safety standards.
What changed
This new Airworthiness Directive introduces a one-time inspection requirement to verify the installation orientation of affected transponders. If the installation is not conventional, the transponder must be removed from service and modified to meet crash safety criteria. The directive also prohibits installation of affected parts unless the installation orientation is conventional.
Why it matters
This directive is critical for aviation professionals because it addresses a safety risk where certain transponder retaining cams may fail under crash conditions if installed incorrectly. Compliance ensures the transponder remains securely mounted during emergency landings, preventing potential damage to fuel systems or evacuation equipment and reducing injury risk to occupants. Operators and maintenance organizations must verify installations and perform modifications to maintain airworthiness and regulatory compliance.
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