L3Harris EA-37B Compass Call

The EA-37B Compass Call (formerly EC-37B) is an electronic warfare aircraft based on the Gulfstream G550 entering service with the United States Air Force with the first example delivered on 23 August 2024 to Davis–Monthan Air Force Base for crew training. The plane is replacing the EC-130H Compass Call.

The role of the Compass Call is to disrupt enemy command and control communications, radars, and navigation systems, significantly hindering adversary coordination as part of the Counter-Command, Control, Computers, Communications, Cyber, Intelligence, Surveillance, and Reconnaissance Targeting (Counter-C5ISRT) mission. The jet will be able to conduct jamming of radars, electronic systems and communications. It will thus be able participate in Suppression of Enemy Air Defenses (SEAD) missions by disrupting an enemy's ability to coordinate sensors and use weapon batteries that target friendly aircraft.

EA-37B are Gulfstream G550 business jet airframes modified with electronic warfare equipment by L3Harris and BAE Systems. The most distinctive feature are the large antenna arrays conformally mounted on either side of the fuselage; these are based on the radar arrays found on the G550 CAEW (Conformal Airborne Early Warning). The aircraft has gone through multiple "Baseline" iterations throughout its development, with Baseline 4 being the latest. It incorporates BAE Systems' Small Adaptive Bank of Electronic Resources (SABER) technology.

Among the equipment also found on the aircraft are: Network Centric Collaborative Targeting (NCCT) systems, System Control and Monitoring subsystems, Radio Frequency Receiver (RFR) subsystems, Software-defined Radio (SDR) subsystems, Counter Radar Assembly, Array Panels, AN/ARC-210 RT-2036 radios, KG-250 In-line Network Encryptors, KY-100 Narrow/wideband Terminals, KIV-77 Mode 4/5 Identification Friend or Foe (IFF), AN/PYQ-10C Simple Key Loaders

On 7 September 2017, the US Air Force awarded L3 Technologies (now L3Harris) a contract to replace the EC-130H Compass Call with an aircraft based on the Gulfstream G550. The new aircraft was expected to "re-host" up to 70% of the mission equipment currently used on the EC-130H.

On 23 October 2018, Secretary of the Air Force, Heather Wilson, approved Air Combat Command's request to replace the EC-130H Compass Call aircraft from the 55th Electronic Combat Group (ECG) located at Davis-Monthan AFB, Arizona, with EA-37B aircraft (then known as EC-37B). The basing decision memorandum was signed on 15 November 2018. The first airframe was delivered to the air force in September 2023 for evaluation and testing.

On 23 August 2024, the first ready aircraft (serial number 19-5591) was delivered to Davis-Monthan AFB to begin pilot training.

The aircraft's first mission training sortie was flown on 2 May 2025 by the 43rd Electronic Combat Squadron out of Offutt Air Force Base, Nebraska.