Northrop delivers jam-resistant LN-351

Northrop Grumman has delivered the first production LN-351, a jam-resistant navigation system slated for the Air Force’s F-22 Raptor and the Navy’s E-2D Advanced Hawkeye. (airandspaceforces.com) (northropgrumman.com) The unit is the modernized Embedded Global Positioning System/Inertial Navigation System, or EGI-M, which Northrop said is built for GPS-contested and GPS-denied environments. Northrop announced the delivery on April 17 from Woodland Hills, California. (airandspaceforces.com) (insidegnss.com) In plain terms, the system mixes two ways of knowing where an aircraft is: GPS signals from space and inertial navigation, which tracks motion internally with onboard sensors. If the GPS piece is jammed or spoofed, the inertial side keeps calculating position, heading and timing. (insidegnss.com) (northropgrumman.com) Northrop says the LN-351 uses fiber-optic inertial navigation and an embedded Military GPS User Equipment receiver that can track M-code, the encrypted military GPS signal. The company says that combination improves resistance to jamming and spoofing over older sets. (northropgrumman.com) (insidegnss.com) The first two aircraft named for fielding are the F-22, the Air Force’s air-superiority fighter, and the E-2D, the Navy’s carrier-based airborne early-warning and battle-management aircraft. The E-2D directs air defense and command-and-control missions for carrier strike groups, making reliable navigation and timing central to its job. (airandspaceforces.com) (navair.navy.mil) Northrop’s product page says the LN-351 is the successor to the LN-251 and uses a tightly coupled design, meaning the GPS and inertial pieces work together inside one integrated unit. The company also says the receiver has 24 channels and can track M-code, P(Y) code and civilian C/A code. (northropgrumman.com) The timing matters because U.S. forces have spent years warning that future operations may involve heavy electronic attack against satellite navigation. Northrop’s assured-navigation division describes its products as meant to preserve positioning, navigation and timing when GPS is compromised or unavailable. (northropgrumman.com 1) (northropgrumman.com 2) For the Navy, the E-2D already serves as an all-weather airborne early-warning and command-and-control platform with the AN/APY-9 radar and carrier strike group mission set. For the Air Force, the F-22 is one of the service’s core fighters for penetrating contested airspace, where navigation backups matter if satellite signals degrade. (navair.navy.mil) (airandspaceforces.com) This delivery was described as the first production unit, not a fleetwide rollout. The next measure will be how quickly LN-351 sets move from initial fielding into operational aircraft on both services’ flight lines and carrier air wings. (airandspaceforces.com) (insidegnss.com)