The certified aircraft technician/engineer is the person qualified and authorized, according to his/her certificate approvals, to take care about aircraft (airplanes and helicopters) maintenance.

Taking care about aircraft maintenance  means to do the required/mandatory maintenance and to sign the Certificate of Release to Service (CRS). CRS has to be signed by a certified aircraft technician/engineer before any flight at the completion of any maintenance.

The certified aircraft technician/engineer is working into an approved/certified company, Aircraft Maintenance Organisation (AMO) or Part-145.

Certification is divided into categories (A and B) and sub-categories (according to the aircraft type, the engine system, etc).


High-school Diploma or equivalent (e.g. High-School/Vocational Diploma)

Basic knowledge of English language

Category A

Line Maintenance

Category B

Base Maintenance

more details from aviation people

Hello I'm John and I'm A.1 certified technician. Line maintenance is the one that is carried out in the ramp and only small or fast maintenance actions are mainly carried out. The main purpose of the line maintenance is to keep the aircraft serviceable at all times so it can perform the scheduled flights. Daily checks are usually carried out during the night for short and medium range aircraft and at random time of the day for long range aircraft, time when the aircraft rests for around 4 to 6 hours depending on the company and the flights it his doing. During this daily check a walk around is done to take a look at the aircraft looking for damage, leaks, wheels, brakes, engine oils are serviced, struts are cleaned… also the cabin and the cockpit are checked. In the line maintenance the weather and time are very important factors affecting the work of the engineer.
John White
A1 Certified Technician
Hi, I'm Isabelle and I'm a B1.1 certified engineer. My main commitment is to perform Base Maintenance. The aircraft enters the hangar and it stays inside for a longer period of time. Base maintenance is where the bigger checks take place, like A, C and D checks. In this checks the aircraft is stripped partly or completely, depending the check, to inspect the different parts of the aircraft. Landing gear, engine, windshield and other big components are also replaced inside the hangar. The time the aircraft remains AOG (Aircraft On Ground) can range from some hours for an APU change to a month for the bigger checks.
Isabelle Smith
B1.2 Certified Engineer


A.1 – B1.1

Airplanes turbine

A2 – B1.2

Airplanes piston

A3 – B1.3

​Helicopters turbine

A4 – B1.3

Helicopters piston




Airplanes piston, non- pressurized < 2000 Kg


The following main elements are required:

  • Basic knowledge
  • Basic experience
  • Type Rating (TR)
  • On Job Training for the first TR


The basic knowledge can be achived by attending a Basic Integrated Course, by examinations or by credits.

The basic experience can be achived by working into any Aircraft Maintenance Organisation (AMO) or Part 145.

The Type Raiting (TR) can be achived by attending a Type Ratining Course (airplane or helicopter), theory and examinations.

The On Job Training (OJT) can be achived by performing maintenance tasks, as for the specific TR, into any  Aircraft Maintenance Organisation (AMO) or Part 145.


A Basic Integrated Course is from 800 (cat A) up to 2400 (cat B) hours. You can also get the basic knowledge module by module (examinations) or by school credits (subject to Authority approval).

After a Basic Integrated Course it is required a 1 (cat A) up to 2 (cat B) years minimum experience into a Part145. If the basic knoledge has been achived module by module or by credits, it is required a 3 years minimum experience.

A Type Rating Course is about four weeks. It depends on aircaft type (airplane or helicopter) and on aircraft complexity.

After the first TR a minum period of On-Job-Training is required. Duration depends on Type Rating type. For any additional TR only Practical Element training is required.

Step 1 & Step 2

After basic knowledge and basic experience you can get a Aircraft Maintenance License (AML). It is blank because you have not a type rating. You should complete this step within 10 years.


Step 3 & Step 4

After the Type Rating training (TR) and the On-Job- Training (OJT), your AML is endorsed with the type rating.You should complete this step (TR and OJB) within 3 years.


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