Aircraft maintenance is the overhaul, repair, inspection or modification of an aircraft or an aircraft component. Usually, the maintenance work of an aircraft includes the installation or removal of a component from an aircraft or an aircraft subassembly and may include tasks such as ensuring compliance or agreement with Airworthiness Directives or Service Bulletins.
Aircraft maintenance does not include:
1. Elementary work which include removing and replacing tires, inspection plates, spark plugs, and checking cylinder compression etc.
2. The servicing work such as refueling, washing windows etc.
3. Any work done on an aircraft or aircraft component as part of the manufacturing process, in order to issue a certificate of airworthiness or other certification documents.
With the exception of certain homebuilt and ultra light planes, all aircraft must carry a valid Certificate of Airworthiness to be legally allowed to fly.
After the completion of any maintenance task, a person authorized by national airworthiness authority signs a release which states that “The described maintenance has been performed according to the applicable airworthiness requirements.” For a certified aircraft the release may be given by Aircraft Maintenance Engineer or Aircraft Maintenance Technician, whereas in the case of amateur-built aircraft, release may be given by owner or builder of the aircraft.
Aircraft maintenance checks are periodic checks that have to be done on all aircraft after certain amount of time or usage. Usually, these checks are of 4 types: A check, B check, C check, D check of which A and B checks are lighter checks and C and D checks are heavier checks.
This check is performed every month or after 500 flight hours and is done overnight usually at an airport gate.
This check is performed every 3 months and it’s also done overnight usually at an airport gate.
This check is performed approximately between 12 – 18 months or a specific amount of actual Flight Hours as defined by the manufacturer. It is usually done at a hangar at a maintenance base as it requires lot of space and usually puts the aircraft out of service for short amount of time.
This check is the heaviest check done on an airplane, also known as heavy maintenance visit or HMV. This check occurs usually every 4 – 5 years. This check must be performed at a maintenance base as it requires even more space and time than all the other types of checks.