Regulation (EU) 2019/1383
ED Decision 2020/002/R
Aircraft equipment should be declared to be defective if the pilot observed a malfunction during the flight, or if considered as faulty after inspection/test referred to in the maintenance data. This does not prevent the pilot from recording observations and comments on the performance of the aircraft equipment where this is not considered to constitute a defect.
ED Decision 2020/002/R
If appropriate certifying staff is readily available for consultation, the pilot should consider consultation with them before deferring any defect.
For balloons not operated under Subpart-ADD, sailplanes not operated under Subpart-DEC, or other aircraft operated under Part-NCO, the pilot may defer required equipment, regardless of whether or not a CAMO or CAO is contracted. However, if doing so, he or she has the obligation to receive the agreement of the owner, or the contracted CAMO or CAO.
The term ‘required’ refers to equipment that is required by the applicable airworthiness code (certification specification) or required by the relevant regulations for air operations or the applicable rules of the air or as required by air traffic management (e.g. a transponder in certain controlled airspace).
ED Decision 2020/002/R
All deferred defects should be made known to the pilot/flight crew, whenever possible, prior to their arrival at the aircraft.
Deferred defects should be listed on the current list of deferred maintenance (ML.A.305(d)(6)) and rectified at the next appropriate maintenance event and within the limit specified in the maintenance data. Any deferred defect that is not rectified during the next maintenance event, should be re- entered on the list of deferred maintenance and the original date of the defect should be retained.
→ ML.A.501