145.A.50 Certification of maintenance

SI 2025 No. 1150

  1. A certificate of release to service must be issued by appropriately authorised certifying staff on behalf of the organisation when it has been verified that all maintenance ordered has been properly carried out by the organisation in accordance with the procedures specified in point 145.A.70, taking into account the availability and use of the maintenance data specified in point 145.A.45 and that there are no known non‑compliances which endanger flight safety.

  2. A certificate of release to service must be issued before flight at the completion of any maintenance.

  3. New defects or incomplete maintenance work orders identified during the above maintenance must be brought to the attention of the person or organisation responsible for the aircraft's continuing airworthiness for the specific purpose of obtaining agreement to rectify such defects or completing the missing elements of the maintenance work order. Where that person or organisation declines to have such maintenance carried out under this point, point (e) will apply.

  4. A certificate of release to service must be issued by appropriately authorised certifying staff on behalf of the organisation after the maintenance that was ordered has been carried out on a component whilst it was off the aircraft . The authorised release certificate ‘CAA Form 1’ referred to in Appendix II of Annex I (Part‑M) constitutes the component certificate of release to service unless otherwise specified in point M.A.502 of Annex I (Part‑M) or ML.A.502 of Annex Vb (Part‑ML). Where an organisation maintains a component for its own use, a CAA Form 1 may not be necessary if so provided in the organisation’s internal release procedures in its MOE.

  5. By way of derogation from point (a), when the organisation is unable to complete all maintenance ordered, it may issue a certificate of release to service within the approved aircraft limitations. The organisation must enter such fact in the aircraft certificate of release to service before the issue of such certificate.

  6. By way of derogation from point 145.A.50(a) and point 145.A.42, when an aircraft is grounded at a location other than the main line station or main maintenance base due to the non‑availability of a component with the appropriate release certificate, the organisation contracted to maintain that aircraft may temporarily fit a component without the appropriate release certificate and the aircraft may fly for a maximum of 30 flight hours or until the aircraft first returns to the main line station or main maintenance base, whichever is the sooner where:

      1. the person or organisation responsible for the aircraft’s continuing airworthiness has agreed to this,

      2. there is a suitable release certificate, and

      3. all other applicable maintenance and operational requirements have been met.

  7. All temporarily fitted components mentioned in point (f) must be removed by the end of the period of time specified in point (f) that the aircraft may fly for unless an appropriate release certificate has been obtained in the meantime under point 145.A.50(a) and point 145.A.42.