A model of what Excalibur might look like shown at RIAT 2023. (Andrew White / Breaking Defense)
RIAT 2023 — The UK’s Excalibur test-bed aircraft, which will evaluate next-generation sub-systems destined for the Royal Air Force’s (RAF) sixth-generation Tempest combat air demonstrator, will begin its flight test program in 2026, the Ministry of Defence recently revealed.
On July 14, the RAF announced an award of a £115 million ($150 million USD) contract to Leonardo UK and 2Excel that effectively transitions the Excalibur Flight Test Aircraft (FTA) into its second phase.
In 2021 the RAF contracted the same companies to conduct preparatory work to modify a retired, narrow-body Boeing 757 airliner to support Tempest. Leonardo and 2Excel subsequently deconstructed and analyzed the air frame to create a “digital twin” to support simulation and modelling of the test program.
As part of this latest contract, Leonardo UK and 2Excel have purchased a second 757 airliner, which is about to undergo modification at 2Excel’s facility in Lasham, Hampshire.
Speaking to the media at Royal International Air Tattoo (RIAT) at RAF Fairford, Gloucestershire on July 14, the RAF’s Future Combat Air System (FCAS) program director, Air Commodore Martin Lowe, described how Excalibur will support the introduction into service of the new Tempest combat aircraft which lies at the heart of the UK’s FCAS strategy as well as the Global Combat Air Program (GCAP).
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Excalibur, which is named after the legendary sword of King Arthur, is planned to have a maximum payload capacity of 14.5 tonnes (16 tons) and will operate at an altitude of 42,000 feet at speeds as high as Mach 0.86. The aircraft has a maximum range of 3,900 nautical miles and endurance of eight hours.
“The new contract will cover the physical modification of the 757, as well as flight tests, certification and the work required to secure approval from the [Civil Aviation Authority],” a Leonardo UK statement confirmed on the same day.
Leonardo UK officials said what they called the “flying laboratory” will begin its Tempest flight tests between “mid-2026 and mid-2028” although funds have yet to be cemented for this subsequent phase.
“The MoD has no fixed backstop,” an official added before suggesting Excalibur could continue flying through until 2040, dependent upon customer requirements.
“The Excalibur project is a key part of FCAS, which will include the crewed fighter and a broader range of capabilities such as uncrewed aircraft, F-35, information systems and weapon systems. Central to the development of the crewed fighter is the [Excalibur] FTA. Leonardo will primarily use the airliner to test new technologies being developed by the trilateral programme,” the statement added.
At RIAT, Leonardo UK’s Director Future Combat Air/GCAP UK Andrew Howard said, “The Excalibur program will help us to accelerate the development of advanced electronics for the integrated sensors, non-kinetic effects (ISANKE) and integrated communications systems (ICS) domain via early flight testing, which can take place in parallel with the wider development of the core platform. This will inject additional pace into the program and support our ambitious goal to deliver a next generation combat aircraft by 2035.”
The UK MoD’s Director, Future Combat Air, Richard Berthon added that the contract is a “milestone for the FTA project and demonstrates our commitment in support of the UK Future Combat Air System. I’m excited that this work will enable us to test, in a live flying environment, some of the highly advanced technology that could feature on the aircraft being delivered by GCAP.”
Leonardo UK’s press statement also described how Excalibur will provide the opportunity to test “underpinning technologies for GCAP in the real-world environment.”
“This is necessary to robustly prove the capability of the complex integrated sensing and communications system technologies required to operate in future threat environments,” the statement said.
The test fight campaign will be flown by 2Excel, carrying on-board scientists and engineers from Leonardo UK. According to Howard, Leonardo UK and the RAF have spent the last 16 months selecting appropriate technologies for the flight test program. Those include radars, antennae, data management systems, machine learning algorithms and sensor fusion technologies.
Sub-systems set to be included are Leonardo’s Multi-Function Radio Frequency System (MFRS)- an evolution of the company’s ECRS Mk2 radar which is currently in development for RAF Typhoon aircraft.
According to Leonardo UK, the MFRS will be capable of providing “over 10,000 times more data than existing systems”.
“The new sensor will collect and process unprecedented amounts of data on the battlespace – equivalent to the internet traffic of a large city such as Edinburgh, every second,” Leonardo documents claimed.
“This huge volume of information, processed on-board, will give Tempest a battle winning edge in combat situations, with the ability to locate and target enemies well before they are targeted themselves,” documents continued before suggesting the sensor also provide a wide range of abilities beyond traditional radar.
Integration of the MFRS on board Excalibur will be of critical importance considering the Tempest Flying Technology Demonstrator will only be carrying a representative radar capability to simulate size and weight specifications.
Ben Griffiths, group communications director at 2Excel confirmed the MFRS will be integrated into the nose of Excalibur with modifications currently being undertaken now. Final internal configurations of Excalibur have yet to be confirmed, although Griffiths suggested it could feature between six and eight workstations.
Howard also suggested discussions with GCAP partners remained ongoing as to whether Excalibur could become an “international asset” to support the multi-lateral effort.
At RIAT, Leonardo UK presented a similar scale model of the Excalibur FTA as displayed at DSEI in 2021. Although the nose of the model aircraft is representative of the Tempest deign, Leonardo UK and 2Excel confirmed to Breaking Defense Excalibur will have an “air force grey” color scheme, similar in style to RAF RC-135W Rivet Joints.
Finally, Howard suggested Excalibur would have “scope to [remotely] operate” uncrewed adjuncts although such a capability is not yet included in the prospective flight test program.
