In its standard use, the term TNA refers to a process aiming to identify the training gap of a person or a group of persons, in order to determine the related need of a training.
However we are here talking about aircraft and more specifically, about the future engineers who need to learn (within an approved Part 147 Training Organisation) how carrying out the high level of aircraft maintenance required by the EASA standard.

The TNA related to the Part-147 is indeed a requirement of the Part-66 (which is linked to the Part-147) aiming to ensure:

  • the coverage of the course syllabus (shown in the Appendix III of the Part 66) and ,
  • the correct duration for each (theoretical) element of such course.

In fact, the way of learning in an EASA environment is through a complete aircraft training, which is made of a theoretical part and a practical part. In our case (fulfilment of Part147/Part66 requirements) the TNA applies to the theoretical part only.

The elements that are object of this process and whose duration should be determined by the TNA, are listed in the Part-66 within a Table identifying them as specific “Chapters” (e.g. Hydraulic Power) to which a related “ATA Chapter” is also assigned (29 for the Hydraulic Power) along with the “Category” (B1, B2 or C) and the “Level” (from 1/low to 3/high depending on the level of detail required for that Category).

The complete table can be found in the “Appendix III of the Part 66 — Aircraft type training and examination standard — On the job training” and here is only reported a small piece of it (Table-1) as simple example:

Table-1: extract of “Airframe System” area

By means of the Training Needs Analysis (TNA)  the Organisation will  then determine the total amount of hours required for each course.
The Part-66 has a table (here Table-2) showing the minimum duration of the courses calculated for a generic aircraft (not a specific type) and in consideration of the estimated average duration of standard type courses imparted in Europe.

This is a quite misleading point of the Part 66 and it is important to highlight that such table (Table-2) should be taken as a reference only as each Organisation should develop its own TNA based on its specific needs.

Each Organisation will then determine whether the Table-2 figures should be extended (increased) or whether should be even reduced, depending on the justifications provided by the TNA.

Table-2: it does not include difference courses or combined courses (i.e. B1/B2).

The TNA should be adapted to the design of the specific aircraft type object of the course, it should take in account such aircraft maintenance needs and the type of operation.
A detailed analysis of the applicable chapters (some reported in Table-1) should be done with the TNA which should result in the insurance that the intended objective of the training is fully met, taking in account the intended Level (1, 2 or 3).

How to develop a TNA is mainly left to the Organisation, which makes things only apparently easy.
In fact the following points should be considered, according to the EASA requirements:

  • The TNA should provide with a reasonable understanding of which areas and elements constitute the course in order to meet the learning objectives,
  • For each Chapter of the theoretical element (a small sample is given in Table-1), the corresponding training time should be recorded,
  • The Aircraft Maintenance Manual, the MRB report, the CMRs, the airworthiness limitations, the Troubleshooting Manual, the Structural Repair Manual, the Illustrated Parts Catalogue, the Airworthiness Directives and the Service Bulletins related to the aircraft object of the course are the typical documents to be used in order to identify the areas and elements where there is a need for training,
  • The above mentioned documents should be subject to TNA in order to determine the impact on the course’s contents of the following activities: “Activation/reactivation tasks”, “Removal/installation tasks”, “Testing”, “Servicing”, “Inspection, check and repairs”, “Troubleshooting/diagnosis”,
  • For the purpose of identifying the specific elements of the course, a filtering method may be used if based on; “Frequency of the Task”, “Difficulty of the Task”, “Human Factor issues associated to the task”, “Criticality and safety impact of there task”, “In-Service Experience”, “Unusual design features”, “Similarities with other aircraft”, “Special tests and tools/equipment”,
  • An approach based on “task/group of tasks” or “systems or subsystems or components” may be also used.

Further details, such as those related to the logical organisation of the aircraft type course and the learning objective, can be found in the AMC to point 3.1(d) of Appendix III to Part 66.
Eventually, it is worth to mention that the Organisation may use in its TNA any analysis done by the Type Certificate Holder (e.g. Airbus or Boeing).