145.A.50 Certification of maintenance
(a) A certificate of release to service shall 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 non-compliances which are known to endanger flight safety.
(b) A certificate of release to service shall be issued before flight at the completion of any maintenance.
(c) New defects or incomplete maintenance work orders identified during the above maintenance shall be brought to the attention of the aircraft operator for the specific purpose of obtaining agreement to rectify such defects or completing the missing elements of the maintenance work order. In the case where the aircraft operator declines to have such maintenance carried out under this point, point (e) is applicable.
(d) A certificate of release to service shall be issued after the required maintenance on a component whilst off the aircraft has been carried out. 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 except if otherwise specified in point M.A.502 of Annex I (Part-M) or ML.A.502 of Annex Vb (Part-ML), as applicable. When an organisation maintains a component for its own use, a CAA Form 1 may not be necessary depending upon the organisation’s internal release procedures defined in the exposition.
(e) By derogation to 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 shall enter such fact in the aircraft certificate of release to service before the issue of such certificate.
(f) By derogation to points (a) and 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, it is permissible to temporarily fit a component without the appropriate release certificate 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, subject to the aircraft operator agreement and said component having a suitable release certificate but otherwise in compliance with all applicable maintenance and operational requirements. Such components shall be removed by the above prescribed time limit unless an appropriate release certificate has been obtained in the meantime under points (a) and 145.A.42.