The airplane is considered the safest means of transport. Air passengers land safely at their destinations more than three billion times a year. To ensure that this remains the case, commercial aircraft are regularly subjected to intensive safety checks, maintenance and overhauls. Lufthansa Technik AG (LHT) is one of the companies that carry out such maintenance, repairs and overhauls. Founded in 1994 as a wholly-owned subsidiary of Deutsche Lufthansa AG, LHT is the parent company of the Lufthansa Technik business segment and the global Technik Group with a total of 53 companies. Contrary to what the name might suggest, the company does not only work for Lufthansa: its customers include almost 800 other airlines and other commercial aircraft operators.

The heart of the company is the overhaul, development and logistics center in Hamburg at the airport. Today, more than 7,500 people work here. They are responsible for the maintenance of engines, equipment and components and the outfitting of large business aircraft. Lufthansa Technik is one of the very few companies in the international group to have a simultaneous license as a manufacturing and development company. "Equipped in this way, we do pretty much everything on the aircraft - even the elaborate outfitting of VIP aircraft with live TV, Internet access, special equipment and other special requests," summarizes Thomas Erich from LHT Corporate Communications.

Phoenix pallet truck automatically retrieves a loaded roll pallet.

Airbus and Boeing are overhauled In Hamburg, it is mainly the larger long-haul aircraft such as the Airbus A330, A340 and Boeing 747 series that are overhauled. While the A-check, a routine maintenance check of technical systems that are important for safe flight operations, can be carried out overnight in the hangar, overhauls take considerably longer. Depending on the aircraft type, they are due every five to six years. Depending on the amount of work required, the aircraft is taken out of service for between 23 and 30 days. During this time, all cabin parts such as seats, galleys, toilets, luggage compartments, inner wall panels and the loading system on the lower deck are removed in a dock in Hamburg, Dock 10, loaded onto roller pallets (LHT pallets) and transported on these with the active assistance of an automated guided vehicle (AGV) from MLR to an interim storage facility, which at LHT is called a high-bay warehouse, with 260 spaces. Spare parts, equipment and tools are also stored here. The three automated guided vehicles (AGVs) also transport the material seven days a week in three shifts to the right workshops at the request of the employees working there. In the workshops, each individual part is thoroughly inspected, repaired if necessary and replaced if required. Once this work has been completed, the components on the roll pallets are returned to the interim storage facility by AGV at the behest of the workers and are kept there with the status "serviceable" until they are called up by a Dock 10 employee for installation in the aircraft.

Freely navigating radar forklifts on tour

The Phoenix R-0.3 MR battery-powered transport vehicles are three-wheel forklift trucks that can move forwards and backwards automatically at a maximum speed of 1.5 m/s. They have a lifting platform as a load handling device with a load capacity of 0.3 tons. They have a lifting platform as a load handling device with a load capacity of 0.3 tons. The load is picked up and dropped off at ground level and - in intermediate storage - up to a height of 5,400 millimetres. The vehicles navigate freely, i.e. they find their way without a guide wire in the floor. The vehicle computer uses the information from the magnetic navigation system to determine the current position and steers the vehicles along the routes generated by the CAD system. The length of the entire AGV route is around 500 meters. Each vehicle is equipped with all safety devices, namely a laser scanner at the front and rear as well as side safety edges. Armored plate lead batteries PzS 48 Volt / 270 Ah provide the energy supply for the vehicles. The battery capacity is designed for an operating time of 16 hours. This means that no battery charging is required during the main operating time. At the end of the late shift, the AGVs automatically drive to an automatic battery charging station. Recharging the batteries takes less than eight hours. To achieve one hundred percent of the transport capacity in the LHT center, two automatic pallet trucks would have been sufficient. The third vehicle is therefore a reserve vehicle, but is integrated into the daily process.

LogOS opens gates

The intelligent core of the system is the multifunctional Logistic Operating System "LogOS", MLR's own software for controlling complex material flow streams. In addition to the transport orders, the master computer also controls the AGVs. The autonomous vehicles have to pass through four roller shutters on their route. As soon as a vehicle approaches the gates, LogOS ensures that the gates open automatically. There is also an intersection with manned forklift trucks and pedestrians on the route set up for the vehicles. It goes without saying that the AGVs have priority over the forklift trucks in all driving course areas.

The driverless transport system from MLR has now been used by Lufthansa Technik employees for around four years. During this time, regular records are kept of the system's availability. Joachim Beck from the vehicle overhaul department at LHT, who knows the system 'like the back of his hand', says: "The availability of the AGV often reaches 99.6 percent every week." A very good value, as the expert confirms.

Wolfgang Degenhard

Contact:

Lufthansa Technik AG 22313 Hamburg Tel.: 0 40 / 5 07 00 E-Mail:

[email protected] www.lufthansa-technik.com

MLR System GmbH 71640 Ludwigsburg Tel.: 0 71 41 / 97 48-0 E-Mail: [email protected] www.mlr.de