Aircraft maintenance at Lufthansa Technik

For safe, reliable and profitable airline operations
World market leader in aircraft technical services

One of the most important factors influencing the success of an airline is the maintenance of its aircraft. Only when the fleet is in a technically excellent state of care can the flying operations be run punctually and profitably. Lufthansa Technik with its more than 22,000 mechanics and engineers in its international group of companies is the world market leader in aircraft technical services, in which maintenance plays a central role.

The maintenance of aircraft is differentiated into line maintenance and overhaul. 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 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 more than one day. For an overhaul, called the IL and D-Check, the aircraft is taken out of service for several weeks. With the overhaul, the D-Check, it is taken apart completely and put back together after every component has been checked, repaired or exchanged. 

Maintenance plan: Precise scope of work

The scope of work has been outlined in the maintenance plan for every check carried out on an aircraft. It starts with the Trip Check: before every take-off the captain or copilot checks the plane. If necessary the mechanics will change the wheels as part of the daily checks. They replace the brakes when the carbon disks have been overheated in a particularly hard braking maneuver. Moreover, they check the aircraft for cracks, corrosion or leakages and check that important systems work perfectly. The oil level in the engines, hydraulic fluid, water and tire pressure are checked every day, the cabin is thoroughly cleaned over night.

The D-Check is the most important aircraft maintenance event. When it comes for an overhaul, a Lufthansa Jumbo Jet has done at least six years of intercontinental service, over 30,000 flight-hours and the some 25 million kilometers that it has flown would be enough to fly more than 30 times from the earth to the moon and back. When the aircraft subsequently leaves the hangar after six 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.  

D-Check: The aircraft is taken apart completely

The D-Checks start with the stripping of the exterior paintwork. The aircraft is taken apart completely and each part checked thoroughly. The engines are put aside and the landing gear is removed. The aircraft is facked up on massive support brackets. Large parts of the outer paneling are removed, uncovering the airframe, supporting structure and wings for a meticulous check. Here, the most modern methods for nondestructive material testing are used. For example, X-rays, eddy current probes and magnetic field checks. These checks detect with the greatest possible reliability any material fatigue, hair cracks or any other damage.

The classical IL-Check is carried out every four to six years, i.e., about halfway between the D-Checks. It serves, in particular, to freshen up the cabin, as well as to check several components. However, recently it has lost in significance. The lifespan and reliability of the systems are continually improving. It is now possible, therefore, to distribute the elements of the IL-Check over several C-Checks or are delayed to the next D-Check. This has been conducted in this way for years with the "flagship" of the international airlines: the Boeing 747-400. The new long-distance aircraft of Airbus will follow this proven prodedure.