The Compass Call Rehost program is now in full swing, with at least five aircraft in production. L3Harris is the prime contractor for the effort to outfit G550 business jets for the communications disruption mission, in partnership with aircraft OEM Gulfstream and primary mission systems lead BAE Systems. The aircraft will be designated EC-37B in U.S. Air Force service.
Last week one of the initial batch paid a visit to Davis-Monthan Air Force Base in Arizona, affording the unit that will operate the EC-37Bs—the 55th Electronic Combat Group (ECG) of the 55th Wing—a chance to inspect their new aircraft. Ground testing of the system is scheduled to begin early next year, with the first five EC-37Bs expected to enter service later in 2023. The current requirement stands at 10 aircraft but is likely to grow to perhaps 14 to replace the EC-130Hs on a one-for-one basis. The 55th ECG has already started the process of phasing out the EC-130H, with five aircraft retired to date.
Compass Call EC-130Hs have been in full U.S. Air Force service since 1983 and have been highly active in virtually all U.S. campaigns since, albeit with little publicity surrounding their sensitive mission. The Air Force description notes that the system “disrupts enemy command and control communications and limits adversary coordination essential for enemy force management. [It] employs offensive counter-information and electronic attack capabilities.”
The capability remains critical to U.S. warfighting ability so as the C-130H platform neared the end of its useful life, the decision was taken to port the system into a younger and more capable airframe. In 2014 the Compass Call Rehost program was launched, with the G550 being selected after a study of available options. Compared with the C-130H, the G550 offers much greater speed, ceiling, and range performance, as well as greater mission flexibility.
A number of regular G550s are already in U.S. military service as C-37B VIP/staff transports but for the Compass Call application, the EC-37B is based on the considerable modifications of the Conformal Airborne Early Warning (CAEW) version, which was developed in conjunction with IAI for the Israeli Air Force. CAEW aircraft have subsequently also been sold to Italy and Singapore. Another aircraft derived from the CAEW modifications is the single NC-37B, which was acquired by the U.S. Navy for range control and support duties with VX-30 at Naval Air Station Point Mugu, California.
EC-37Bs are being built and modified by Gulfstream in Savannah, Georgia, and L3Harris in Waco, Texas. The first of the aircraft flew in its new configuration on October 7 last year. The initial five EC-37Bs are being delivered in the Baseline 3 system configuration, which repackages the mission equipment of the EC-130Hs for installation into the Gulfstream.
The remaining aircraft are due to be delivered in the Baseline 4 version, which is expected to feature a new jamming system. Baseline 4 is thought to include the BAE Systems Small Adaptive Bank of Electronic Resources (SABER) system, which allows Compass Call to transition to what the company said is a “software-based electromagnetic spectrum warfare capability.” The open-architecture system allows the mission suite to be updated easily to meet emerging threats without costly and time-consuming hardware changes.