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Aircraft technical log system

M.A.306

M.A.306(a) Contents

(a) In addition to the requirements of point M.A.305, for CAT, commercial specialised operations and commercial ATO or commercial DTO operations, the operator shall use a 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.

AMC M.A.306(a) Content of information on the ATLS

For CAT operations, commercial specialised operations and commercial ATO or commercial DTO operations, the aircraft technical log is a system for recording defects and malfunctions during the aircraft operation and for recording details of all maintenance carried out on an aircraft between scheduled base maintenance visits. In addition, it is used for recording flight safety and maintenance information the operating crew need to know.

Cabin or galley defects and malfunctions that affect the safe operation of the aircraft or the safety of its occupants are regarded as forming part of the aircraft log book where recorded by another means.
The aircraft technical log system may range from a simple single section document to a complex system containing many sections but in all cases it should include the information specified for the example used here which happens to use a 5 section document / computer system:

Section 1 should contain details of the registered name and address of the operator the aircraft type and the complete international registration marks of the aircraft.

Section 2 should contain details of when the next scheduled maintenance is due, including, if relevant any out of phase component changes due before the next maintenance check. In addition this section should contain the current certificate of release to service (CRS), for the complete aircraft, issued normally at the end of the last maintenance check.


NOTE: The flight crew do not need to receive such details if the next scheduled maintenance is controlled by other means acceptable to the competent authority.

Section 3 should contain details of all information considered necessary to ensure continued flight safety. Such information includes:

(i) the aircraft type and registration mark,
(ii) the date and place of take-off and landing,
(iii) the times at which the aircraft took off and landed,
(iv) the running total of flying hours, such that the hours to the next schedule maintenance can be determined. The flight crew does not need to receive such details if the next scheduled maintenance is controlled by other means acceptable to the competent authority.
(v) details of any failure, defect or malfunction to the aircraft affecting airworthiness or safe operation of the aircraft including emergency systems, and any failure, defect or malfunctions in the cabin or galleys that affect the safe operation of the aircraft or the safety of its occupants that are known to the commander. Provision should be made for the commander to date and sign such entries including, where appropriate, the nil defect state for continuity of the record. Provision should be made for a CRS following rectification of a defect or any deferred defect or maintenance check carried out. Such a certificate appearing on each page of this section should readily identify the defect(s) to which it relates or the particular maintenance check as appropriate.
In the case of maintenance performed by a Part-145 maintenance organisation, it is acceptable to use an alternate abbreviated certificate of release to service consisting of the statement ‘Part-145 release to service’ instead of the full certification statement specified in AMC 145.A.50(b) paragraph 1. When the alternate abbreviated certificate of release to service is used, the introductory section of the technical log should include an example of the full certification statement from AMC 145.A.50(b) paragraph 1.
(vi) the quantity of fuel and oil uplifted and the quantity of fuel available in each tank, or combination of tanks, at the beginning and end of each flight; provision to show, in the same units of quantity, both the amount of fuel planned to be uplifted and the amount of fuel actually uplifted; provision for the time when ground de-icing and/or anti-icing was started and the type of fluid applied, including mixture ratio fluid/water and any other information required by the operator’s procedures in order to allow the assessment on whether inspections for and/or elimination of de-icing/anti-icing fluid residues that could endanger flight safety are required.
(vii) the pre-flight inspection signature.
In addition to the above, it may be necessary to record the following supplementary information:
— the time spent in particular engine power ranges where use of such engine power affects the life of the engine or engine module;
— the number of landings where landings affect the life of an aircraft or aircraft component;
— flight cycles or flight pressure cycles where such cycles affect the life of an aircraft or aircraft component.


NOTE 1: Where Section 3 is of the multi-sector ‘part removable’ type, then such ‘part removable’ sections should contain all of the foregoing information where appropriate.
NOTE 2: Section 3 should be designed so that one copy of each page may remain on the aircraft and one copy may be retained on the ground until completion of the flight to which it relates.
NOTE 3: Section 3 layout should be divided to show clearly what is required to be completed after flight and what is required to be completed in preparation for the next flight.

Section 4 should contain details of all deferred defects that affect or may affect the safe operation of the aircraft and should therefore be known to the aircraft commander. Each page of this section should be pre-printed with the operator’s name and page serial number and make provision for recording the following:


(i) a cross reference for each deferred defect such that the original defect can be identified in the particular section 3 sector record page.
(ii) the original date of occurrence of the defect deferred.
(iii) brief details of the defect.
(iv) details of the eventual rectification carried out and its CRS or a clear cross-reference back to the document that contains details of the eventual rectification.

Section 5 should contain any necessary maintenance support information that the aircraft commander needs to know. Such information would include data on how to contact maintenance if problems arise whilst operating the routes etc.

M.A.306(b) Initial issuance, amendment control

(b) The initial issue of aircraft technical log system shall be approved by the competent authority specified in point CAMO.A.105 of Annex Vc (Part-CAMO), or point M.1 of this Annex (Part-M) or point CAO.1(1) of Annex Vd (Part-CAO), as applicable. Any subsequent amendment to that system shall be managed in accordance with point CAMO.A.300(c), or points M.A.704(b) and (c), or point CAO.A.025(c).

AMC M.A.306(b) ATLS format

The aircraft technical log system can be either a paper or computer system or any combination of both methods acceptable to the competent authority.
In case of a computer system, it should contain programme safeguards against the ability of unauthorised personnel to alter the database.

Updated on 12/05/2021

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