Part 21J Design


The EASA Mandate for compliance with ADS-B Out operation in all European Airspace is due by 7th June 2020. (Automatic Dependant Surveillance – Broadcast) The countdown has begun, time IS running out, don’t leave it too late and unable to operate…… This requirement is mandated by EASA and can be summarised as follows; Mandated by EU Regulation No 1207/2011 of 22nd November 2011 and amended by EU Regulation No 1028/2014 of 26th September 2014. It lays down the requirements for the performance and interoperability of surveillance for the single European Sky and states that;

Operators shall ensure that by 7th June 2020, all fixed wing aircraft (5,700Kg or > 250Kts), with an individual C of A first issued before 8th June 2016 are equipped with secondary surveillance radar transponders having the capabilities set out in Annex II (ADS-B Additional Surveillance Data). (Further in-depth details can be supplied upon request).

Our Part 21J EASA Approved Design Organisation is pleased to offer a survey and assessment of your aircraft to determine your best route to an EASA Approved ADS-B Out certification solution. The Modification could be embodied during your next Heavy Maintenance visit to Medavia by our Part 145 Maintenance and Installtion team or could be suppled as a STC Kit for in-house embodiment.

Our ADS-B Out ‘Aircraft Survey’ form below will enable us to assess your equipment upgrade requirements and assist us in providing the best possible solution.

WHAT’s it all ABOUT ?

Mandated by 7th June 2020, applicable to all a/c of 5,700Kg & above and greater than 250Kts. The requirement; to automatically transmit, up to 25 different aircraft data parameters to ATC, via the ATM ground stations throughout Europe. Why; to achieve a European ‘Open Skies’ traffic management system to reduce departure, enroute and arrival delays and cater for future air travel growth.


From an engineering perspective new certification requirements have been mandated and are required for compliance, e.g EASA CS.25 & CS.ACNS. In summary, various avionic system upgrades are required to satisfy the certification requirements in terms of capability, performance and compliance. The main systems needed for ADS-B Out compliance are as follows;

  1. Mode S (Extended Squitter) Transponder (dual recommended) – Transponder/s must be RTCA DO-260B, ETSO-C166b & EASA ETSO-C112d qualified.
  2. FMS/GPS/SBAS system – FMS/GPS system/s must be RTCA DO-229, ETSO-C129a or ETSO-C196 qualified.
  3. Second FMS/GPS (required to satisfy reliability requirements).
  4. GNSS/SBAS compatible antennae (2) – Antennae must be RTCA DO-301, TSO-C190 qualified.
  5. Txpndr L Band antenna diversity (2) – 1 top and 1 bottom antenna per transponder.
  6. ADS-B/Txpndr FAIL annunciators – in cockpit instrument Panel.


  • Your existing Transponder/s, GPS/FMS and antennae will not be compliant and will need to be replaced.
  • Your existing aircraft ‘air data’ system/s is/are unable to provide the required data parameters in ‘digital format’ and that the ‘ADC’ is not ETSO-C106 qualified.
  • In older aircraft this will normally require an ADC/DADC replacement or upgrade by the OEM if available.


  • A detailed review of the current aircraft systems interface wiring diagrams is required to ensure that all of the aircraft data parameters are actually available and digitally compatible. (Analogue to Digital converter/s may be required).
  • A full design & certification documentation package to embody the modification will be raised.
  • EASA have mandated the modification as an STC Major Change under current ruling, EASA fee is also applicable.


  • An Approved EASA STC certification package will be produced, generally comprised of the following documents;
  • Design Change Specification report, Design Change Classification Review, Design Change Certification Plan, Design Change Compliance Checklist report. Structural/Stress & Fatigue Analysis report, ELA report, Wt & Bal Report. Equipment Safety Assessment reports, System Functional Hazard Analysis report, Modification Certificate of Approval


  • Service Bulletin (embodiment instructions), Wiring Diagram interface drawings, Structural installation drawings, Ground Test Procedure report, EMI/EMC Test Procedure report, Instructions for Continued Airworthiness, Maintenance Manual Supplement and Flight Manual Supplement/s.


  • The overall costs can be categorised into equipment costs, design costs & certification costs.
  • Every aircraft configuration will have variations and it is imperative that we obtain a clear understanding of your current avionics configuration to enable us to provide accurate and cost-effective pricing.
  • We have provided our ADS-B Out website portal link where you can complete our ‘on-line’ survey and submit it with a click of a button.
  • Upon receipt and review of the survey form we will be able to provide you with a cost-effective solution for your aircraft upgrade.

Please, don’t leave it too late, 7th June 2020 is not that far away…

Medavia Technics

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