Aircraft maintenance at Lufthansa Technik

Отличный текст, чтобы разобрать основную лексику в разделе «техническое обслуживание ВС». Несложный, но крайне полезный. Оригинал взят с сайта Lufthansa Group, где можно почерпнуть по теме ещё много интересного (ссылка - https://www.lufthansagroup.com/en/themen/aircraft-maintenance-at-lufthansa-technik.html).

После текста можно проверить и закрепить «активную» лексику.

Only when the fleet is in a technically excellent state of care can the flying operations be run punctually and profitably. Lufthansa Technik is the world market leader in aircraft technical services, in which maintenance plays a central role.

Maintenance plan: Precise scope of work

The lowest-level maintenance event is the pre-flight check that precedes every flight and involves an inspection of the aircraft by the cockpit crew and, if necessary, by mechanics. This check for visible external damage or leaks lasts between 15 and 60 minutes, depending on the aircraft type.

The next maintenance event in the hierarchy is the ramp check, in which mechanics test individual functions of the aircraft, inspect the tires and brakes and replenish the oil and hydraulic fluids. A visual inspection of the aircraft is also carried out, both externally and in the cabin. 

The A- and C-checks are significantly more labor-intensive. The A-check is carried out every 350 to 750 flying hours. As well as general inspections of the interior and the aircraft hull, it also covers service checks as well as engine and function checks. If any extensive seat repairs are required, these are also carried out in this interval inspection.

Even more detailed is the maintenance work carried out in connection with the C-check, the biggest maintenance event before an overhaul (base maintenance). This entails thorough inspections inside and outside, along with meticulous examination of structures (load-bearing components on the fuselage and wings) and functions. For example, the technicians would use ultrasonic techniques to look for cracks in critical components. For the C-check an aircraft will spend up to five days in the maintenance hangar.

D-Check: The aircraft is taken apart completely

The D-Check is the most important aircraft maintenance event. The aircraft is taken apart completely and each part checked thoroughly. Here, the most modern methods for nondestructive material testing are used. For example, ultrasound and eddy current probes and magnetic field checks. These checks detect with the greatest possible reliability any material fatigue, hair cracks or any other damage. When the aircraft subsequently leaves the hangar after four weeks it is better than new: not only will everything have been repaired or exchanged that can wear in the slightest, moreover all product improvements in the technology and passenger comfort that have been launched by the manufacturers over the past years will have been installed. 

The classical IL-Check is carried out every four to six years, i.e., about halfway between the D-Checks.

What is the difference between aircraft line maintenance and overhaul (base maintenance)?

The maintenance of aircraft is differentiated into line maintenance and overhaul (base maintenance). The work that has to be done in the short term is called line maintenance. This means that the aircraft keeps to its usual schedule. The daily, weekly and monthly checks are, especially for short-haul flights, carried out over night. The next morning the aircraft goes back into scheduled service. Merely the C-Check that is carried out about every one and a half years takes somewhat longer. For an overhaul (base maintenance), called the IL and D-Check, the aircraft is taken completely out of service for several weeks.