In general the ETSO authorization needs to be in place for continued airworthiness purposes. Even if your company might have stopped production a long time ago there could still be units in service.
In order to have an ETSO certificate surrendered please send an e-mail request (application form not available) to new [dot] applications [at] easa [dot] europa [dot] eu . State the approval number and the reason for the surrender. You will receive a confirmation e-mail containing the next steps, which are usually:
- allocation of the surrender exercise to EASA PCM or NAA
- notification of all ICAO states about the intended surrender
- analyse the comments of this notification
- accept or refuse the requested surrender
- revoke the certificate
- update the list of EASA products
- notification of the revocation to the public.
Following this, a PCM would check the issue and if found o.k. we would issue a Certification Information with comment period and following the feedback received, later the final Certification Information. The PCM will also decide if it is necessary to have a comment period or if the issue can go right to the decision and the final certification information. Once the surrender has been decided you will receive a decision letter and you will have to return the original certificate to EASA.
The Certification Information is published on the EASA website on the latest news page and also under the Type Certificates Information page.