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.

Design 
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

History 

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.

Designation 
Originally designated EC-37B, as an electronic warfare version of the C-37B transport jet under the tri-service aircraft designation system. The designation was officially changed to EA-37B on 14 November 2023 to better reflect the aircraft's role and capabilities although the name change had been hinted at before. The new designation does however conflict with that of the unrelated A-37 Dragonfly, itself a non-systematic designation.

Operators 

 United States Air Force :  10 aircraft on order, one delivered as of November 2024. Operated by the 55th Electronic Combat Group, a part of Air Combat Command.

 The Italian Air Force plans to acquire two EA-37B Electronic Attack mission system packages to convert two Gulfstream G550 into EA-37B. The $680 million sale was approved by the US State Department on October 7, 2024. Note these are not to be confused with the G550 CAEW also operated by the Italian Air Force.

Specifications

See also 

 Gulfstream G550
 EC-130 Compass Call
 EL/W-2085
 MC-55A Peregrine

References 

EA-37B
EA-37B
Twinjets
2020s United States electronic warfare aircraft
Electronic countermeasures
Low-wing aircraft
Aircraft with retractable tricycle landing gear