Northrop Grumman said the first unit of its fiberoptic gyro inertial navigation system — the LN-260 — has been delivered to the U.S. Navy for flight testing on the F-5 Tiger II Adversary Fleet Support Fighter. The F-5N/F is a twin-engine, tactical fighter commonly used for adversary combat tactics to simulate enemy aircraft in aerial combat training exercises. Flight testing of the upgraded F-5 is to begin in October; the aircraft will be operational next year. The F-5 Navigation/Radar Display kit replaces five legacy components comprising the navigation, navigation controls and radar display functions with two line replaceable units. The kit includes the LN-260 INS, which has an embedded GPS receiver, an integrated Control Display Unit and a radar display designed and developed by Interface Displays and Controls in Oceanside, Calif. Kits will be integrated into F-5 aircraft at Northrop Grumman's facility in St. Augustine, Fla.