Running a practiced eye over the data, Ivaylo Krastev, engine engineer at MTU Maintenance Hannover, sees that an engine is experiencing a drop in efficiency while cruising. The outlet temperature has risen, the high-pressure spool is speeding up and the engine is consuming more fuel. A warning is immediately sent to the airline, which has its entire fleet of engines looked after by MTU Maintenance. At the aircraft’s next stop, the engine is examined while still on the wing by two of the airline’s maintenance mechanics using a borescope.
They discover that a foreign body has found its way into the compressor. The engine is immediately removed from the wing and sent to the MTU Maintenance shop for repair. There, the fears are confirmed: the foreign body has damaged several blades. Had this comparatively minor damage gone unnoticed, it could have caused major consequential damage to the engine and led to costly repairs— the airline is now spared both of these.