How Aircraft Maintenance Services Are Performed


Commercial airplanes facilitate the daily lives of thousands of people who need to travel from one point to another in the world quickly. These powerful machines carry hundreds of passengers on each flight, so they must undergo complete control and maintenance to ensure the safety of every one of the passengers, including, of course, the crew.

Aircraft maintenance services consist of a series of periodic inspections that must be carried out on all commercial/civil aircraft after a specific period or after a particular period of use. Airlines and other commercial aircraft operators are governed by a continuous inspection program approved by the European Aviation Safety Agency (EASA) in Europe and by the Federal Aviation Administration (FAA) in the United States.

Aircraft maintenance services include inspection and repair of aircraft structures and aircraft coatings and systems in hangars or at the airport. Good training and good work practices ensure the safety of the worker and the aircraft.

Aircraft maintenance services or MRO (Maintenance, Repair, and Overhaul) has always been one of the most delicate points in aviation, both when an aircraft flies due to high operating costs and when it fails for lack of a spare part, making it inoperative. In both cases, very high fixed charges are incurred.

There are different types of aircraft maintenance services overhauls performed on a scheduled basis according to plan to keep the aircraft in the best possible shape. Similarly, unscheduled overhauls will be carried out whenever any breakdown or problem is detected in the machine.

In-transit checks

These are carried out before each flight or stopover to check general aspects of the aircraft, such as the condition of the tires, oil level, etc.

Daily checks

Each day the oil level is checked about 15 to 20 minutes after the engines are shut down, at which time the reading will be more accurate.

48-hour checks

Every 48 hours, general issues in the aircraft condition are checked, such as checking wheels and brakes, replenishing fluids, inspecting the airframe and interiors, etc.

Time-limit checks

When an aircraft flies for too many hours, reaching almost the limit of its capabilities, it is necessary to check engines and other systems and controls operating continuously.

Operating Limit Cycle Checks

Some aircraft elements are inspected depending on the number of cycles performed (set of takeoffs and landings) because they are used. These overhauls include the landing gear, turbine blades, engine components, etc.

PS Overhaul

This is a periodic overhaul service carried out by some airlines. In this overhaul, the aircraft is visually inspected to rule out other maintenance needs.

Letter overhauls

This maintenance program is performed at the most appropriate times for the system or equipment. It aims to ensure passenger safety and guarantee the perfect condition of all aircraft components.

Overhaul A

It is performed approximately every 400 flight hours or every 200 cycles. The duration of this overhaul is about 10 hours, and between 50 and 70 operators are needed to complete it.

Overhaul B

It complements overhaul A to check other elements in depth. It is performed every 4 to 6 months and lasts from one to three days.

Revision C

This overhaul is performed every 20 to 24 months or when the aircraft reaches a certain number of flight hours, generally set by the manufacturer. It is an in-depth overhaul, which takes about one or two weeks of work, and is performed in a vast hangar, leaving the aircraft inoperative during that time.

Overhaul D

This is the most specific type of overhaul on an aircraft, performed approximately every six years. Each part of the aircraft is revised, changing all the necessary elements, including the paint and the fuselage. It lasts two months, so it is scheduled well in advance.

The stipulated time intervals between the different maintenance inspections depend on the aircraft manufacturer and the aircraft operator. These checks usually rely on the aircraft’s total number of flight hours and aircraft cycles (number of landings).