The GE90 Growth at MTU Maintenance Hannover

Putting engines through their paces

The midday bells ring out on Hannover’s Markt­kirche (market church). Around ten kilo­meters further north, at MTU Main­tenance Han­nover in Langen­hagen, a GE90-115B is being rigged up in the test cell. This is the world’s biggest and most power­ful engine. MTU’s tech­nicians hook up the multi­coupling system, which allows the engine meas­uring points and test cell meas­ure­ment system to be con­nected with a single click. At the same time, they con­nect the control and supply lines. In the next step, the bolts of the engine mounting are passed through the openings in the thrust measuring bridge. MTU’s staff work fast and fully focused. While testing gets under­way in the test cell, the tech­nicians in the rigging center are get­ting the next engine ready. And next door, they are packing up the engine that has just come off the test cell.

During the test run, the GE90-115B is put through its paces. “We adapt the ac­cept­ance test run for each engine to the scope of the shop visit,” explains Thomas Michaelis, senior manager, engine testing. In the control center, the tech­nicians push the thrust lever and run the engine at full load. A 115,000-pound thrust is brought to bear on the test cell. The air­flow rate is more than 1.5 metric tons per second. A dozen monitors display all relevant infor­mation, graphi­cally en­hanced and collated in real time: exhaust tem­pera­ture, air­flow, generated thrust and fuel con­sumption. A test run takes around ten hours. However, if refine­ments are required, it can sometimes take considerably longer.

The GE90 Growth has been part of MTU Main­tenance Han­nover’s portfolio for more than seven years; Han­nover is one of the first main­tenance shops worldwide to obtain a license for the repair and complete over­haul of this engine family.