ML.A.401 Maintenance data

Regulation (EU) 2021/700 (EU) 2021/700

(a) The person or organisation maintaining an aircraft shall only use applicable maintenance data during the performance of maintenance.

(b) For the purposes of this Annex, “applicable maintenance data” means any of the following:

1. any applicable requirement, procedure, standard or information issued by the competent authority or the Agency;

2. any applicable AD;

3. the applicable ICA and other maintenance instructions, issued by the type-certificate holder, supplementary type-certificate holder and any other organisation that publishes such data in accordance with Annex I (Part 21) to Regulation (EU) No 748/2012;

4. for components approved for installation by the design approval holder, the applicable maintenance instructions published by the component manufacturers and acceptable to the design approval holder;

5. any applicable data issued in accordance with point 145.A.45(d).

GM1 ML.A.401(b) Maintenance data

ED Decision 2021/009/R

Similar provisions to those in GM1 M.A.401(b)(3) and (b)(4) and GM1 M.A.401(b)(4) apply.

ML.A.402 Performance of maintenance

Regulation (EU) 2019/1383

(a) Maintenance performed by approved maintenance organisations shall be in accordance with Subpart F of Annex I (Part-M), Annex II (Part-145) or Annex Vd (Part-CAO), as applicable.

(b) For maintenance not performed in accordance with point (a), the person performing maintenance shall:

(1) be qualified for the tasks performed, as required by this Annex;

(2) ensure that the area in which maintenance is carried out is well organised and clean with no dirt or contamination;

(3) use the methods, techniques, standards and instructions specified in the maintenance data referred to in point ML.A.401;

(4) use the tools, equipment and material specified in the maintenance data referred to in point ML.A.401. If necessary, tools and equipment shall be controlled and calibrated to an officially recognised standard;

(5) ensure that maintenance is performed within any environmental limitations specified in the maintenance data referred to in point ML.A.401;

(6) ensure that proper facilities are used in case of inclement weather or lengthy maintenance;

(7) ensure that the risk of multiple errors during maintenance and the risk of errors being repeated in identical maintenance tasks are minimised;

(8) ensure that an error-capturing method is implemented after the performance of any critical maintenance task;

(9) perform a general verification after completion of maintenance to ensure that the aircraft or component is clear of all tools, equipment and any extraneous parts and material, and that all access panels removed have been refitted;

(10) ensure that all maintenance performed is properly recorded and documented.

AMC1 ML.A.402  Performance of maintenance

ED Decision 2020/002/R

(a) Examples of acceptable methods to record and document the maintenance performed are the following:

               a copy of the 100-h/annual inspection checklist with ticks and signature; and

               a copy of the release to service indicating the tasks performed.

(b) Airborne contamination (e.g. dust, precipitation, paint particles, filings) should be kept to a minimum to ensure aircraft/components surfaces are not contaminated. If this is not possible, all susceptible systems should be sealed until acceptable conditions are re-established.

AMC1 ML.A.402(b)(7)  Performance of maintenance

ED Decision 2020/002/R

To minimise the risk of errors and to prevent omissions, the person performing maintenance should ensure that:

(a)  every maintenance task is signed off only after completion;

(b)  the grouping of tasks for the purpose of sign-off allows critical steps to be clearly identified; and

(c)  any work performed by personnel under supervision (i.e. temporary staff, trainees) is checked and signed off by an authorised person.

CRITICAL MAINTENANCE TASKS

The following maintenance tasks should primarily be reviewed to assess their impact on safety:

(a)  tasks that may affect the control of the aircraft’s flight path and attitude, such as the installation, rigging and adjustments of flight controls;

(b)  tasks that may affect aircraft stability control systems (autopilots, fuel transfer);

(c)  tasks that may affect the propulsive force of the aircraft, including the installation of aircraft engines, propellers and rotors; and

(d)  the overhaul, calibration or rigging of engines, propellers, transmissions and gearboxes.

ERROR-CAPTURING METHODS

Re-inspection, when only one person is available to carry out the task, or independent inspection, are possible error-capturing methods.

ML.A.403 Aircraft defects

Regulation (EU) 2019/1383

(a) Any aircraft defect that seriously endangers the flight safety shall be rectified before further flight.

(b) The following persons may decide that a defect does not seriously endanger flight safety, and may defer it accordingly:

(1) the pilot in respect of defects affecting non-required aircraft equipment;

(2) the pilot, when using the minimum equipment list, in respect of defects affecting required aircraft equipment — otherwise, these defects may only be deferred by authorised certifying staff;

(3) the pilot in respect of defects other than those referred to in points (b)(1) and (b)(2) if all the following conditions are met:

(i) the aircraft is operated under Annex VII to Regulation(EU) No 965/2012 (Part-NCO) or, in the case of balloons or sailplanes, not operated under Subpart-ADD of Annex II (Part-BOP) to Regulation (EU) 2018/395 or not following Subpart DEC of Annex II (Part-SAO) to Regulation (EU) 2018/1976;

(ii) the pilot defers the defect with the agreement of the aircraft owner or, if applicable, of the contracted CAMO or CAO;

(4) the appropriately qualified certifying staff in respect of other defects than those referred to in points (b)(1) and (b)(2), where the conditions referred to in point 3(i) and (ii) are not met.

(c) Any aircraft defect that does not seriously hazard flight safety shall be rectified as soon as practicable from the date on which the defect was first identified and within the limits specified in the maintenance data.

(d) Any defect not rectified before flight shall be recorded in the aircraft continuing airworthiness record system referred to in point ML.A.305 and a record shall be available to the pilot.

AMC1 ML.A.403  Aircraft defects

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.

GM1 ML.A.403  Aircraft defects

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).

AMC1 ML.A.403(d)  Aircraft defects

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.