When aviation first began, pilots like J.A.D. McCurdy and Glenn Curtiss were their own maintenance technicians – they designed, built and flew the aircraft themselves. Once aircraft were mass produced during the First World War, aircraft engineers came into their own. Schools were opened where candidates with demonstrated technical expertise were apprenticed. Back then, the simplicity of early engines and air frames meant that the educational requirement for an Aircraft Maintenance Engineer (AME) was completion of high school. But today, preference is given to candidates who, in addition, have completed a technical course at a recognized institution, such as a Transport Canada approved school or a university degree.

A variety of skilled trades are involved in the maintenance of aircraft, especially those aircraft used in an airline.

• Aircraft Line Maintenance – Technicians diagnose and correct troubles on the aircraft, carry out minor and major aircraft checks and effect repairs. In order to be eligible for promotion above the level of Technician in this classification, a certificate of competence is required.
  
  
• Aircraft Engine Overhaul Maintenance – Technicians maintain aircraft engines, including dismantling, inspecting, assembling and testing.
  
  
• Aircraft Avionics involve the maintenance of electronic systems on the aircraft such as communications, navigation, autopilot and flight recording.
  
  
• Aircraft Sheet Metal and Plumbing Technicians maintain aircraft structural components and parts.
  
  
• Aircraft Electrical and Electronic Accessories – Technicians are engaged in the overhaul and assembly of electrical/electronic accessories, equipment and harnesses, and/or such reconditioning, repair and testing of electrical accessories and equipment as may be required.
  
  
• Trim Overhaul and Fabrication – Technicians are engaged in the overhaul and repair of all aircraft furnishing, fabric work (which includes chairs, carpets, drapes and panelling) and fabrication parts.
  
  
• Machining and Fitting – The trade of Machinist, as related to Aircraft Maintenance, covers the wide variety of machine tools working in fine tolerances.
  
  
• Aircraft Technician Systems Maintenance – Technicians perform shop maintenance functions on units and parts related to aircraft mechanical and fuel systems accessories, hydraulic, and pneumatic systems.
  
  
• Aircraft Instrument Maintenance – Technicians perform shop maintenance functions on aircraft instruments and related components. These are of a precise nature and are linked to many aircraft systems.
  
  
• Painting includes all paint work relating to the aircraft, engines, units and ground equipment.
  
  
• Welding refers to the welding of aircraft components, engine parts and related repair work.
  
  
• Aircraft Wheel and Rubber Unit Maintenance – Technicians maintain the aircraft wheels, brakes and tires. Other components, such as life preservers, rubber rafts and oxygen masks, are also maintained by this unit.
  
  
• Heat Treating and Processing concerns the heat treating techniques and plating of various metals.
  
  
• Aircraft Cleaning refers to the cleaning of aircraft exteriors (including furnishings) and other operational cleaning functions relative to aircraft, parts and associated equipment.
  
  
• Engine Parts Cleaning and Blasting – Technicians are engaged in the operation and servicing of blasting equipment and the cleaning of aircraft engine parts and associated equipment in the engine shop.
  
  
• Radio and Electronic Overhaul and Repair involves the overhaul and assembly of aircraft radio and electronic equipment (including radio communications and radio navigational aid equipment) and/or such reconditioning, repair and testing as may be required.