Given how complex modern aircraft are, it’s only appropriate that inspections and maintenance procedures are exhaustive. With so many pieces of equipment, safety requires persistent vigilance from both the pilot and the technician. Routine check-ups can also ensure a properly functioning aircraft—avoiding costly repairs down the line.
The majority of an aircraft’s maintenance and inspections will revolve around the standards set by Title 14 in the Code of Federal Regulations, or 14 CFR. According to 14 CFR, there are three primary types of inspections: annual, 100-hour, and progressive. An annual inspection must occur once every year. 100-hour inspections are required of all aircraft that carry non-crew passengers. A progressive inspection is a special program where the requirements of the 100-hour inspection is broken up into multiple phases. For example, instead of one inspection every 100 hours, you could have five inspections over the same period of time, each one covering a portion of the 100-hour inspection. These progressive inspection plans require a special application and are typically utilized by owners of high-use aircraft fleets.
Components frequently inspected by the FAA in annual or 100-hour inspections include the altimeter, transponder, emergency locator transmitter, as well as the angle fuselage, engines, and propellers. Inspectors search for signs of wear and tear, malfunctioning components, and damage. This includes deterioration and loose fittings in the fuselage and wings, cracks and failed sealing in the windows, and any leakage in hydraulic lines for brakes and landing gear.
Before every flight, the pilot has to make a preflight inspection to ensure their aircraft’s integrity. This includes a cabin inspection, to make sure that the necessary paperwork is on hand (including airworthiness and registration certificates, operating handbook, weight and balance data, etc.), and ensuring that all electric switches and toggles are in the right position. It’s also important to clear the cockpit of loose trash and tools. Next is the exterior inspection, a walk-around where the pilot checks for loose rivets and bolts in the fuselage, making sure there are no leaks in the fuel reserves, checking the tires for wear and flats, and clean the windows. These tasks may seem minor, but each one is vital for a safe flight.
When it comes to maintenance there are two categories: preventative and progressive. Preventative maintenance involves tasks that don’t require a great deal of disassembly or complex repairs; small, easy procedures that a pilot or mechanic can perform to keep the aircraft working properly such as cleaning, replenishing engine fluids and sealing, or replacing small pieces of hardware. Under 14 CFR Part 61, these tasks can be performed by anyone holding a pilot certificate, as long as the aircraft is not used to carry non-crew passengers. Otherwise, a mechanic certified by the FAA must perform them.
The FAA classifies all repairs as minor or major. Which category a repair falls under depends on its complexity and how important it is to the aircraft’s critical systems. Both types must be performed by an FAA-approved mechanic; however, after minor maintenance an aircraft can return to the air with the approval of the mechanic or repair facility. Major maintenance requires inspection by a mechanic with an Inspection Authorization, or by a representative of the FAA.