Manufacturing and mainte- nance Manufacturing processes An excellent example of MTU’s capabilities is the manufacture of compressors in blisk design, where disk and blades come as one piece. One of the techniques used in the man- ufacture of these high-tech components is linear friction welding, a process that reduces the consumption of raw material while at the same time ensuring a high-strength welded joint between the precision-forged airfoils and the disk body. The patented linear friction welding technique has been developed by MTU in Munich. Other processes used in blisk manufacturing are high-speed milling and electro-chemical machining, which have also been developed or matured for this particular application by MTU. The individual blisk stages are joined by inertia friction welding. MTU’s Munich location boasts a highly advanced inertia welding machine. It is 20 meters long and produces upsetting forces of up to 1,000 metric tons. It joins components together to tolerances of ten hundredths of a millimeter. Inspection engineering and metrology Products used in aviation must be flawless. To make sure they are, MTU is continuously improving its inspection methods along the entire supply and manufacturing chain. It uses highly advanced computer tomography and ultrasonic inspection to reveal flaws in cast materials of sizes 30 percent smaller than de- tectable otherwise. While it helps to detect flaws, it is even more desirable to prevent them. This is where on- line in-process inspection takes center stage. On critical components, quality-relevant man- ufacturing process data is captured digitally to immediately and reliably alert engineers to process deviations. Maintenance Whether airline or leasing company, cus- tomers are all pursuing the same objective of minimizing engine maintenance costs with- out violating specified safety standards. The largest single item in maintenance is material cost. It amounts to as much as 70 percent of the layout for a shop visit. MTU’s strategy is that “repair beats replace- ment”. In the development of new repair tech- niques, MTU can draw on its unique expertise derived in the development and production of numerous engine programs. Typical examples are the patch repair technique for blisk airfoils, or blade tip repair by laser powder cladding. Thus, the company achieves levels of restora- tion that are unique worldwide. 15 MTU boasts the world’s most precise inertia welding machine. Turbine center frames are being produced in a dedicated shop at MTU’s Munich location. MTU is the only company worldwide that repairs blisk airfoils by patching.