EASA Part-M
Regulation (EU) No 2042/2003
M.A.306 Operator’s technical log system

(a) In the case of commercial air transport, in addition to the requirements of M.A.305, an operator shall use an aircraft technical log system containing the following information for each aircraft:

1. information about each flight, necessary to ensure continued flight safety, and;
2. the current aircraft certificate of release to service, and;
3. the current maintenance statement giving the aircraft maintenance status of what scheduled and out of phase maintenance is next due except that the competent authority may agree to the maintenance statement being kept elsewhere, and;
4. all outstanding deferred defects rectifications that affect the operation of the aircraft, and;
5. any necessary guidance instructions on maintenance support arrangements.

(b) The aircraft technical log system and any subsequent amendment shall be approved by the competent authority.
(c) An operator shall ensure that the aircraft technical log is retained for 36 months after the date of the last entry.