Northrop Grumman recently delivered the first production-version of a new upgraded, jam-resistant airborne navigation system for the Air Force’s F-22 Raptor and Navy’s E-2D Advanced Hawkeye aircraft.
The Embedded Global Positioning System/Inertial Navigation System Modernization (EGI-M) is designed for missions into GPS-contested and GPS-denied environments, according to a Northrop release on April 17. Its official military designation is LN-351.
EGI-M uses M-code, the military-only GPS signal from the most advanced GPS III satellites using high-gain directional antennas. These signals are less vulnerable to jamming than standard GPS signals.
The encrypted M-code signals also enable blue force tracking systems to follow U.S. military aircraft through GPS-jammed areas. All military GPS gear acquired after fiscal 2017 must be M-code-capable.
In a Northrop release, Lt. Col. Christopher Grover, the PNT program office materiel leader at the Air Force Life Cycle Management Center, said the new “receiver allows our U.S. military assets the ability to go where we want to, with the capability we need, at the time of our choosing.”
Ryan Arrington, Northrop Grumman’s vice president for navigation and cockpit systems, said in the release that “EGI-M enhances operational effectiveness and is built with the flexibility to defeat today’s threats and adapt to future mission demands.”
In addition to providing jam-resistant navigation, the new system also has:
- Flexible software: The system can host third-party PNT applications tailored to specific navigation functions, enabling EGI-M to integrate with other sensors and track non-GPS satellites.
- Modular design: It can integrate with an aircraft’s existing platform navigation systems and is designed to allow for future advanced technology upgrades.
- Production: Upgraded from the existing LN-251 navigation system, EGI-M has already completed necessary technical and performance testing and is set for full-scale manufacturing.
Northrop began engineering and manufacturing development of the EGI-M in 2018 and completed critical design review in 2020.
In May 2023, the company successfully tested the system aboard a Cessna Citation 560 aircraft. And in February 2025, EGI-M was one of three variants tested in six performance evaluation flights by the Air Force Life Cycle Management Center.
Northrop has said that while the EGI-M is slated for initial fielding in the F-22 and E-2D Advanced Hawkeye, other fixed- and rotary-wing assets could also adopt the system as an upgrade in the future. Among those systems that could upgrade from the current LN-251 to EGI-M are the RQ-4 Global Hawk and MQ-4C Triton remotely piloted aircraft, the P-8 Poseidon maritime patrol aircraft, and the CH-53K King Stallion helicopter.
Back in 2019, the Air Force awarded Northrop a contract worth up to $1.39 billion over 13 years to produce and sustain next-generation navigation systems for USAF and foreign military sales customers.