B check: This check is conducted about every 6-8 months. It takes about 160-180 person-hours, depending on the type of aircraft and its condition. It is generally completed within 1–3 days at an airport hangar.
C check: The C check is conducted approximately every 20–24 months, or after a specified number of flight hours, or as specified by the manufacturer. This maintenance check is much more thorough and comprehensive than the B check and requires all the aircraft components to be inspected. This type of check puts the plane out of service for 1–2 weeks. It also requires more space and is therefore performed in an airport hanger or maintenance base.
