The MC-55A Peregrine is part of Australia’s effort to strengthen ISR and EW capabilities with airborne electronic attack and SIGINT capabilities integrated on a Gulfstream G550 airframe.
The RAAF’s (Royal Australian Air Force) MC-55A Peregrine EW/SIGINT (Electronic Warfare/Signal Intelligence) appears to have commenced its second test flight campaign, as shown by the newly emerged photographs by aviation photographer @SR_Planespotter. Sharing the images on X, the photographer said the aircraft (tail number N540GA) arrived at L3Harris’ facility at Greenville in Texas “in its completed, fully modified state.”
SR_Planespotter was kind enough to share these images with The Aviationist and also sent us pictures of another MC-55A Peregrine (tail number N542GD) spotted at Greenville, Texas. The aircraft is on the taxiway, and the images capture the plane from various angles, along with close ups of the rear fuselage, engines and a ventral sensor array.
The first MC-55A Peregrine for the @AusAirForce arrives at L3 Harris Greenville for test flight 2 in its completed, fully modified state. pic.twitter.com/wkRSrhBTFs
— 𝙎𝙍_𝙋𝙡𝙖𝙣𝙚𝙨𝙥𝙤𝙩𝙩𝙚𝙧 (@SR_Planespotter) January 22, 2025
Both these aircraft bear the RAAF’s roundel on the engine nacelles and under the wings. It also bears what appears to be the logo of the RAAF’s No. 10 Squadron on the vertical stabilizer. One of the images of N542GD shared by SR_Planespotter shows the starboard (right-side) engine’s thrust reverser partially deployed.
Prior to this, on Sep. 11, 2023, SR_Planespotter shared pictures of N584GA, which at the time was still sporting the factory paint scheme, coming in to land at Majors Airport in Greenville, Texas, with the callsign GLF09. The MC-55A Peregrine is based on the Gulfstream G-550 business jet, the production of which was completed in Apr. 2020, before it could be converted into the MC-55A Peregrine aircraft.
The MC-55A Peregrine’s prominent feature and role would be linking in a single network other electromagnetic sensing, electronic reconnaissance and strike platforms like the RAAF’s F-35A Lightning II, E-7A Wedgetail AEW&C (Airborne Early Warning and Control) and the highly capable E/A-18G Growler.
The last time the aircraft N540GA, seen in the latest set of images, was spotted, it was shared on Instagram by @aarons_airplanes on May 7, 2022, in a green factory paint primer, while flying from Gulfstream’s plant in Savannah, Georgia. The G-550 is also the aircraft of choice for Italy’s similar JAMMS (Joint Airborne Multi-sensor Multi-mission System) and the U.S. Air Force EA-37B Compass Call EW aircraft, which are currently being modified with the requisite systems by L3Harris.
RAAF’s MC-55A Peregrine program
The RAAF says that acquisition of the MC-55A Peregrine is a part of a plan to strengthen ISR (Intelligence, Surveillance and Reconnaissance) and EW capabilities, which also involves upgrades to the E/A-18G Growler’s “electronic capability” and enhancing the Jindalee Operational Radar Network that provides wide sea and air surveillance of the approaches to Northern Australia. On Dec. 6, 2024, Raytheon, a subsidiary of RTX Corporation, was awarded a $590 million contract for the production of the Next-Generation Jammer-Mid Band pods to equip the USAF and the RAAF E/A-18G Growler fleets.
According to Scramble, the MC-55As will be based at RAAF Edinburgh, South Australia. The location already hosts the AP-3C Orion, the P-8 Poseidon fleet and the Air System Development and Test Wing equipped with the F/A-18A/B and PC-9/A. RAAF Edinburgh also hosts the reformed No. 9 Squadron that will operate the service’s four MQ-4C Triton aircraft, which would be based at RAAF Base Tindal, Northern Australia.
Brand new MC-55A Peregrine (N584GA) for the RAAF as ” GLF09 ” coming into KGVT from KSAV on 9/7/23! #Australia #Texas #Gulfstream #avgeek #aviationphotography #aviation pic.twitter.com/j5XEs3Xuij
— 𝙎𝙍_𝙋𝙡𝙖𝙣𝙚𝙨𝙥𝙤𝙩𝙩𝙚𝙧 (@SR_Planespotter) September 11, 2023
Program history
The RAAF’s MC-55A Peregrine program follows an Aug. 2016 plan to acquire airborne SIGINT and EW capabilities within Project AIR 555. On Jun. 23, 2017, the U.S. Defense Security Cooperation Agency (DSCA) notified the Congress of the approval of a possible a Foreign Military Sale (FMS) to Australia of five Gulfstream G-550 aircraft for information gathering, surveillance and reconnaissance, and electronic warfare, worth $1.3 billion.
This was followed by Australia’s Department of Defense announcing on Mar. 18, 2019, the acquisition of four modified Gulfstream G550 aircraft, for which Canberra’s then defense minister Christopher Pyne earmarked $2.46 billion. Reports have said that the first MC-55A was scheduled to arrive in Australia in late 2022 or early 2023, with deliveries expected to be concluded in 2025.
“The Peregrine is a new airborne electronic warfare capability that will be integrated into Defence’s joint warfighting networks, providing a critical link between platforms, including the F-35A Lightning II, E-7A Wedgetail, EA-18G Growler, Navy’s surface combatants and amphibious assault ships and ground assets to support the warfighter,” Pyne had said in a statement at the time.
Aircraft features
The MC-55A’s most prominent feature is a canoe-like array below the fuselage, which reports have said could host a large AESA (Active Electronically Scanned Array) or a GMTI (Ground-Moving Target Indicator) radar. It could also host an RF emission sensor to conduct electronic attacks from standoff ranges, although it is not clear if the canoe can host more than one sensor.
The aircraft sports multiple dorsally mounted antennas, possibly related to multi-band HF/VHF/UHF radio and satellite communications suites and data-linking transceivers, as well as several blade antennas below the wings and fuselage, which can be safely assumed to be used for signal collection. There is also a large antenna fairing on top of the vertical stabilizer.
A bulbous tail cone, similar to the CAEW’s one, can also be seen, and an informed guess suggests a desired capability to have electromagnetic sensing for ELINT, SIGINT and COMINT (Communications Intelligence) purposes from the rear-aspect. There is also what appears to be an EO/IR (Electro-Optical/Infra-Red) ball turret below the tail for elementary optical surveillance and ISR capability, given the vast maritime stretches surrounding Australia, and the intermittent presence of PLA Navy vessels there.
Specific information on these sensors is currently not available. L3Harris says that, under the Peregrine program, it is “delivering four modified G550 aircraft with an integrated mission system that provides the latest EW capabilities for the Australian Defence Force (ADF).”
Thanks again to @SR_Planespotter for allowing us to use the photos and make sure to follow him on X for more!
