Northrop Grumman Corp. has been awarded a contract by EADS Defence & Security, through its Military Air Systems business unit, to deliver 88 inertial measurement units (IMUs) for Tranche 3A of the Eurofighter Typhoon. The IMUs will be built by the company's German navigation systems subsidiary, Northrop Grumman LITEF, which also provided IMUs for Tranche 1 and Tranche 2 of the aircraft. Developed as part of the flight-control system of the Eurofighter Typhoon, the IMU system is the sole sensor that measures the motion of the aircraft and continuously provides motion data to the flight-control computer to drive the control systems and actuators. In a secondary function, the IMU provides backup navigation data. More than 400 LITEF IMUs have been delivered and are already in service on the Eurofighter in Germany, Spain, Italy, U.K., Austria, and Saudi Arabia.