Aircraft Trivia: Airframe Maintenance

 Airframe Maintenance

Usually referred to as a preflight inspection (T-maintenance), this includes a visual inspection of the entire aircraft, refueling, and checking the aircraft for departure readiness. There are four levels of aircraft maintenance: A maintenance, B maintenance, C maintenance, and D maintenance.

Since A maintenance is performed every 300 to 400 hours of flight time and takes into account the number of takeoffs and landings, it is performed approximately once a month, at night in the hangar, and the aircraft is ready for operation the next day. A maintenance focuses on replenishment of engine oil, hydraulic oil, oxygen, etc., as well as the moving blades, tires, brakes, engine, etc.

B maintenance is performed in addition to A maintenance and includes a detailed inspection, especially of the engine.

C maintenance is performed every 3,000~4,000 hours of flight time and takes approximately one week. During this period, operations are suspended and a spare aircraft is used as a replacement. Because of the downtime period, the schedule is adjusted to avoid overlap with the peak season. In addition to A and B maintenance, the maintenance includes careful inspection of piping, wiring, engines, and landing gear, inspection of the fuselage structure, refueling of various parts, and time replacement of equipment. Larger airlines can perform this maintenance in-house, but smaller airlines may outsource it to a company specializing in airframe maintenance.

D maintenance is performed once every 4~5 years on a large scale, taking about one month. The aircraft's paint will be removed and it will be reborn as new. Since the aircraft will be out of service for a month, it will affect the operation of the aircraft, and companies that lease their aircraft generally take this opportunity to lease a new one.

The large companies may also sell their aircraft to the used aircraft market during this period.