With a handful of defence journalists including ESD as the audience, UK unmanned system/munitions specialist Overwatch Group and US unmanned aerial vehicle (UAV) designer PteroDynamics conducted the first demonstration flight in the UK of the Transwing X-P4 UAV on 18 July 2024.
From a field adjacent to the Overwatch facilities near Reading, Berkshire, the X-P4 took off vertically, with its wings folded and their four electrically powered propellers pointing skyward, before seamlessly transitioning into fixed-wing mode as the UAV’s wings moved into position for level flight. The UAV then performed a series of circuits over the field before retransitioning for a vertical landing.
The demonstration on 18 July came in advance of the first X-P4 flight demonstrations to government and industry stakeholders at the site on 22 and 23 July.
The unique dihedral folding wing system of the XP-4, which generates more surface area for greater lift and load-carrying stability with less power, has been designed to overcome the challenges of carrying significant payloads while delivering the range required to provide enhanced operational effect.
The electrically powered XP-4 prototype, originally designed by PteroDynamics in response to a US Navy requirement, has a 6.8 kg maximum payload, a 65 kt (120 km/h) cruising speed, an endurance of one hour and a 60 n mile (111 km) range at its maximum take-off weight (MTOW) of 41 kg. The UAV currently has a wingspan of 4 m, although Tim Whitehand, vice president of engineering at PteroDynamics and the designer of the XP-4, suggested during the demo on 18 July that a production-standard X-P4 is likely to be slightly larger.
The X-P4, however, is the first of a family of Transwing UAVs. The X-P5 Maritime, which is currently in the detailed design stage, will be larger, with a 6 m wingspan and an MTOW of 150 kg. Powered by a hybrid electric/internal combustion engine combination, the X-P5 Maritime is expected to have a maximum range of 1,200 n miles and an endurance of 19 hours at its MTOW.
The X-P7 Maritime, meanwhile, which is currently at the conceptual design stage, will be larger still, with a wingspan of 10 m and an MTOW of 1,400 kg. Powered by turbines, the X-P7 Maritime is expected to have a maximum range of 1,000 n miles and an endurance of 9 hours at its MTOW.
PteroDynamics has so far produced a dozen X-P4 prototypes, of which the US Navy owns three. These are currently being assessed by the US Naval Air Warfare Center Aircraft Division (NAVAIR NAWCAD) for the Blue Water Maritime Logistics Unmanned Aerial System (BWUAS) programme, which addresses automated long-range maritime resupply missions.
Beyond the defence sector, Transwing UAVs also have significant applications in the commercial sector, for example by automating maritime logistics and resupply for the offshore oil and gas industry.
It was only on 1 July 2024 that Overwatch Group and PteroDynamics announced they had entered into a landmark long-term strategic relationship under which Overwatch has become the exclusive sales representative for Transwing UAVs on behalf of PteroDynamics within the UK for all non-commercial sales, as well as in the United Arab Emirates (UAE) and Saudi Arabia for all prospective commercial and defence sales. Overwatch, which has already established an office in the UAE, has also made a strategic investment in PteroDynamics.
Overwatch Group, which was formed in 2020 and currently employs around 30 personnel, made its name in the UK defence sector by designing, developing and producing its Phonos range of pack-portable loitering munitions (LMs), which are propelled by two pairs of contra-rotating propellers. The company has so far produced a thousand of these munitions under contract to the UK Ministry of Defence, with the first 100 examples delivered within seven weeks of going on contract. It was this agility that drew the attention of Colorado-based PteroDynamics, with Whitehand noting, “We chose the relationship with these guys strategically; we’re also risk-takers.”
The two companies are resolved to stay small and agile, responding to the needs of their customers. Overwatch CEO Drew Michael remarked on 18 July, “If you have a direct link to the users, that’s how you iterate fast.”
Overwatch thus seems set to break the mould of small/medium enterprises (SMEs) that, having achieved some degree of success, then simply get bought out by a major defence prime and thus lose the agility that allowed them to innovate in the first place.
“I have no intention to sell this business,” said Michael. “My biggest passion about setting up the company was to give the MoD a viable alternative.”
SMEs generally have a high bar to negotiate in terms of the financial and other stipulations required by the UK MoD to receive defence contracts, but Overwatch appears to be showing a way forward in this respect, having primed for its contract to supply the MoD with LMs. Speaking on 18 July, Michael envisaged a construct under which various SMEs could band together to present a unified set of stipulations that they could all sign up to, thus facilitating the possibility of small but agile defence-related SMEs actually securing business with the UK MoD.
