L3Harris · Airborne Electronic Attack / Communications Jamming / Electronic Attack · USA · Digital Age (2010–present)
Open in interactive gallery →See aircraft like this on the live radar →The L3Harris EC-37B Compass Call is an American electronic-warfare aircraft developed by L3Harris, with BAE Systems as principal subcontractor, to replace the EC-130H Compass Call on a Gulfstream G550 airframe. IOC was achieved in August 2023 with the 41st Electronic Combat Squadron at Davis-Monthan AFB, Arizona, giving the U.S. Air Force a stand-off communications-jamming and electronic-attack platform built around contemporary processors and antennas. It is one of the few new dedicated USAF electronic-warfare aircraft fielded in the 2020s — a category the service had largely set aside after retiring the EF-111A in 1998.
Built on the Gulfstream G550 business jet, the EC-37B measures 96 ft (29.4 m) long with a 93 ft (28.5 m) wingspan. Empty weight is around 48,300 lb and maximum take-off weight is 91,400 lb. Two Rolls-Royce BR710 turbofans of about 15,385 lbf each push the aircraft to roughly 530 mph (Mach 0.85), well above the EC-130H's 350 mph turboprop cruise. Service ceiling reaches 51,000 ft against the EC-130H's 33,000 ft, lifting the platform above most ground-based air-defence engagement envelopes. Range is about 6,750 nmi, far beyond the EC-130H's roughly 2,000 nmi. Crew is typically eight — two pilots and six electronic-warfare officers and EW operators — down from the EC-130H's thirteen.
The EC-37B's job is stand-off communications jamming and electronic attack: disrupting enemy command-and-control links, air-defence networks, and other networked targets. Its mission package descends from the EC-130H Compass Call but is rebuilt around the AN/USC-X (specific designation classified), which provides wide-bandwidth signals processing, AESA-driven antenna apertures, an updated software architecture, and integrated cyber-effects operations. Operators can simultaneously detect, classify, and locate hostile emitters across wide bandwidths; jam multiple targets with directional precision; inject cyber-effects payloads into linked targets; and gather signals intelligence.
Initial fielding came in August 2023 with the 41st Electronic Combat Squadron at Davis-Monthan AFB — the same unit flying the EC-130H, allowing both types to operate in parallel during transition. Combat deployment to the U.S. Central Command (CENTCOM) area of operations followed in 2024. More than 10 EC-37Bs are on order through 2027 to replace the 14 EC-130Hs, with room for further procurement. Conversion of commercially purchased Gulfstream G550 airframes takes place at L3Harris's Greenville, Texas facility. Each aircraft costs roughly $300–400M USD against about $50M for a base G550, the difference reflecting the BAE Systems contribution. The EC-37B is the first new dedicated USAF electronic-warfare platform since the EF-111A entered service in 1981 — a 42-year gap that mirrors the broader retreat from dedicated EW aircraft in U.S. Air Force doctrine since the 1990s.
The L3Harris EC-37B Compass Call is an American electronic warfare jet. It is built from the Gulfstream G550 business jet. The EC-37B replaces the older EC-130H Compass Call. It entered Air Force service in August 2023 with a squadron in Arizona.
The EC-37B is 96 feet long with a 93-foot wingspan, smaller than a Boeing 737. Two Rolls-Royce BR710 jet engines each make 15,385 pounds of thrust. Top speed is about 530 mph, faster than most race cars. The EC-37B flies up to 51,000 feet, much higher than the old EC-130H.
The EC-37B's job is jamming enemy radios and command links from far away. American forces use jamming to confuse enemy command. The new AN/USC-X jammer is built around fast computers and large flat-panel antennas. The EC-37B can detect, identify, and jam enemy signals at the same time.
The EC-37B has 8 crew, down from 13 on the older EC-130H. New computers do more of the work. The Air Force ordered 10 or more EC-37Bs to replace the 14 old EC-130Hs by 2030. The EC-37B can fly farther, higher, and faster than the old plane, while doing the same jamming job with fewer crew.
The EC-37B is faster, flies higher, and has better computers than the old EC-130H. It is a Gulfstream business jet instead of a C-130 turboprop. The EC-37B reaches more places quicker and stays above most enemy missiles. The 8-person crew is smaller because new computers do more of the jamming work.
Electronic attack means using radio signals as weapons. The EC-37B sends powerful signals that confuse enemy radios, radars, and computer networks. This stops enemy forces from coordinating attacks, without dropping bombs. Modern wars are part radio-vs-radio, and the EC-37B is one of America's best electronic attack tools.
The Air Force ordered only about 10 EC-37Bs, replacing the 14 EC-130Hs. The newer jet is more capable, so fewer can do the same job. The EC-37B is also expensive: each one costs over $200 million. The Air Force is buying them slowly as the EC-130Hs retire by 2030.
The two platforms differ across nearly every dimension. The EC-130H is a four-engine turboprop with a 350 mph top speed, 33,000 ft ceiling, 13 crew, 2,000 nmi range, and a 1980s-derived mission suite. The EC-37B is a two-engine turbofan jet with a 530 mph top speed, 51,000 ft ceiling, 8 crew, 6,750 nmi range, and the AN/USC-X mission suite. Practical gains include faster transit to the target area, higher operating altitude above most ground-based air defence, longer mission radius, updated avionics, and a smaller crew. Trade-offs include higher jet-fuel consumption than the C-130's turboprops and the lower survivability of a commercial airframe in austere or damaged-base operations.
Several factors drove the choice. (1) The 51,000 ft service ceiling places the aircraft above most ground-based air-defence engagement envelopes. (2) The 6,750 nmi range supports global deployment without forward basing. (3) Mission endurance runs 10 hours and beyond. (4) Operating cost per flight hour is lower than for dedicated military airframes. (5) The modern airframe accepts contemporary avionics integration. (6) The U.S. military already had familiarity with the G550 from existing ISR programmes. The EC-37B fits a wider U.S. trend toward business-jet special-mission aircraft alongside types like the RC-12 and MC-12W Liberty, driven by acquisition cost, operating cost, and ease of upgrade.
BAE Systems is the principal mission-package subcontractor. The AN/USC-X (specific designation classified) provides the primary signals-detection, classification, jamming, and cyber-effects functions. BAE Systems Electronic Systems division in Nashua, New Hampshire leads suite development, drawing on its USAF EW heritage including the AN/USC-48 system carried on the EC-130H Compass Call. L3Harris is prime contractor for aircraft conversion and integration at its Greenville, Texas facility. The L3Harris–BAE partnership has been the principal U.S. Air Force EW prime team since the 1990s.
Typical mission endurance is 10 to 12 hours on internal fuel, extending to 16 hours and beyond with air-to-air refuelling. Service ceiling is 51,000 ft and cruise speed is Mach 0.85, around 530 mph. Combat radius runs roughly 3,000 nmi for typical missions, well above the EC-130H's 1,000 nmi. The combination of speed, altitude, and endurance opens the mission envelope sharply — especially for Indo-Pacific work, where the long distances between potential operating areas made the EC-130H's range a constraint.
Six concrete gains. (1) Higher-altitude operations at 51,000 ft against 33,000 ft, above most ground-based air-defence engagement envelopes. (2) Faster theatre arrival at Mach 0.85 against Mach 0.45, cutting transit time from CONUS. (3) AESA-driven antenna apertures that improve electronic-attack performance against modern threats. (4) Expanded cyber-effects operations enabled by the new software architecture. (5) An 8-crew rather than 13-crew complement, lowering personnel costs and simplifying training. (6) A modern mission-suite architecture that is easier to upgrade than the EC-130H's legacy AN/USC-48.
The U.S. AN/USC-X mission suite is unlikely to be exported in full, given its highly classified electronic-attack and cyber-effects content. Several allied nations are instead pursuing G550-based electronic-warfare aircraft fitted with their own national mission kit: Italy has roughly two G550 EW platforms under procurement, Israel could upgrade its existing G550 'Eitam' EW fleet, and Australia is studying the option. These mirror the EC-37B concept but use Italian or Israeli mission kit rather than U.S. equipment. Direct export of the EC-37B with the full U.S. mission package has not been approved.