Aircraft Maintenance Checks Overview: A, B, C and D Checks Explained Aircraft maintenance is not performed randomly. Instead, it follows a structured and scheduled system known as maintenance checks . These checks ensure that aircraft remain safe, reliable, and airworthy throughout their operational life. Scheduled aircraft maintenance checks based on flight hours, cycles, and calendar time The most common scheduled maintenance checks are: A Check B Check C Check D Check Each check has a specific scope, frequency, and level of inspection. Basis of Maintenance Checks Aircraft maintenance checks are scheduled based on: Flight hours – Total hours the aircraft has flown Flight cycles – One takeoff and landing equals one cycle Calendar time – Daily, weekly, monthly, or yearly intervals These intervals are defined by the aircraft manufacturer and approved by aviation authorities such as FAA and EASA. A Check The A Check is a light and frequent ma...

Aircraft Maintenance Types & Checks Explained: Line, Base, A, B, C & D Checks Aircraft maintenance is a critical part of aviation safety. Every flight you see in the sky is made possible by a structured maintenance system designed to keep aircraft safe, reliable, and compliant with aviation regulations. This article explains the main types of aircraft maintenance and the commonly used maintenance checks (A, B, C, and D) in a clear and beginner-friendly way. It is ideal for aviation students, maintenance trainees, mechanical engineers, and aviation enthusiasts. What Is Aircraft Maintenance? Aircraft maintenance includes all actions required to ensure an aircraft remains airworthy . These actions include inspections, servicing, repairs, replacements, and checks performed according to approved maintenance programs. Maintenance is: Mandatory under aviation regulations Planned and documented Essential for flight safety Performed by licensed and approved pe...