BAE Systems' TEMPEST 5th-Gen MRCA Unveilled

At BAE Systems’ Farnborough Airshow pavilion on July 16, the UK’s Defence Secretary Gavin Williamson unveilled a full-scale conceptual model of a fifth-generation MRCA that would be developed through international industrial partnerships. BAE Systems’ CEO Charles Woodburn said that the UK government’s new Combat Air Strategy—released on the same day—“is a powerful statement of intent to invest.” Royal Air Force’s (RAF) Chief of the Air Staff Air Chief Marshal Sir Stephen Hillier said that the RAF is "taking ownership of our next-generation capability.”

The conceptual model was generated by Team Tempest, a partnership between the RAF’s Rapid Capabilities Office (RCO) and the UK-based industry (including BAE Systems, Leonardo UK, MBDA UK and Rolls-Royce). The Tempest comes out as a large, manned twin-engine and twin-tail design with a near-delta wing, except for trailing-edge indentations for stealth alignment. Additional images on display next to the model also showed a scaled-down unmanned version, and industry officials have since cautioned that the model should not be considered definitive, although some wind-tunnel testing has been done already.

According to Williamson, more than US$2.65 billion would be invested in the UK’s Future Combat Air Strategy (FCAS) by 2025. The UK’s industry is contributing up to 50% of this on some of the 60 “national technology demonstrations” that form part of the FCAS. Williamson said that Team Tempest should deliver a business case by the year’s end and take “initial conclusions” on international partners (like Japan( by next summer. Further, he said, the partners could be “nations around the world, including ones that we haven’t worked with before.” He continued: “Early decisions on how to acquire the capability will be confirmed by the end of 2020, before final investment decisions are made by 2025. The aim is to have operational capability by 2035.”

Officials from Team Tempest later clarified that no commitment has yet been made to build a flying demonstrator in the near-term. “We could do some tests on existing platforms,” said BAE Systems’ Air Strategy Director Michael Christie. He added that the size of the model on display had been driven by the need for a large payload bay, whether for weapons, sensors or additional fuel. One accompanying illustration showed four small drones in the bay that could be launched in a "swarm" concept of operations. The MBDA Meteor beyond-visual-range air-to-air missile and Spear-3 air-to-surface PGM was also on display, but an MBDA official said that the definitive MRCA could carry future weapons from the pipeline of developments already projected by MBDA and the UK Ministry of Defence. They will likely include hypersonic and directed-energy weapons.

Conrad Banks, Chief Engineer for Future Defence Programmes at Rolls-Royce, described advanced engine technologies that would be incorporated. These include distortion-tolerant fan systems; two embedded starter-generators that eliminate the accessory gearbox and would provide greatly increased and continued electrical power; advanced composite materials providing a “step-change” in thrust-to-weight ratio; and a fully-integrated thermal management system.  Other characteristics of a future MRCA include a “virtual cockpit”; reconfigurable communications; network-enabled cooperative engagement; artificial intelligence and machine learning; “intrinsic ISR"; multispectral sensors fully integrated at the subsystem-level; and advanced digital manufacturing processes.

But Air Commodore Linc Taylor, Head of the RCO and Team Tempest, noted that a spiral strategy would be employed to leverage existing technologies. “We will re-use what’s good enough already,” he said, adding that this would particularly apply to mission data reprogramming. His boss, Air Vice Marshall "Rocky" Rochelle, Chief of Staff for Capability and instigator of the RCO, said: “We are working at pace, and breaking traditional paradigms.” He added that past lessons about unnecessarily complicated and protracted developments were being learned. While admitting, “We will get some things wrong,” he also accepted, "We should be measured by the outcomes.”

In unveilling its vision for a potential successor to the Eurofighter EF-2000, the UK has thus upped the stakes in an ongoing European dogfight for supremacy in producing a fifth-generation MRCA. Nations including Japan, Sweden and Turkey are among those that the UK would be willing to work with, while the companies behind a separate Franco-German project have called for greater collaboration between European nations, potentially incorporating the UK. “The UK is fully open to international partnership,” said ACM Sir Hillier. “It is an entirely fitting way for the RAF to enter its second century.” Responding to the Tempest concept’s unveilling, Airbus Military Aircraft has said that it “is encouraged to see the UK government’s financial commitment to the project, which supports the goal of sovereign European defence capability”. “A FCAS of utmost importance to Europe’s armed forces and therefore we look forward to continuing collaborative discussions in this area with all relevant European players,” Airbus added.

Japan’s homegrown effort to develop a fifth-generation MRCA are led by the state-owned Technical Research & Development Institute (TRDI) which had, In July 2014, unveilled photographs of its then engineless experimental Advanced Technology Demonstrator (ATD-X) being towed out of a paint shop at the Mitsubishi Heavy Industries’ (MHI) Komaki South Plant in Nagoya. The ATD-X was born out of a feasibility study programme that was launched in 2007. Originally, what is now the ATD-X was then given the enigmatic codename Shinshin, the two-kanji combination that has the general meaning of mind or spirit, but this appellation is no longer used. In addition to the undertaking of research into flight control systems that would enable super-manoeuvrable flight, a more sinister-looking, full-scale radar cross section (RCS) model was tested at a French government facility in the latter half of 2005 and displayed at the Japan Aerospace Expo in 2008 after the conclusion of that stage of development. The ATD-X’s low RCS-optimised fuselage cross section, described as like that of an abacus bead, arose from that research. The RCS model was followed by flyable, one-fifth scale models, one of which was revealed in 2006. From that year, five years of parallel research were conducted into the so-called smart skin, whereby the external fuselage structure is embedded with self-diagnostic micro-sensors.

Manufacture of the ATD-X and a ground-test airframe commenced in 2009. As its full name implies, the ATD-X will be used as a testbed for research and systems integration. The aircraft is intended to act as a stepping stone on the way toward the possible production of a scaled-up, next-generation MRCA, incorporating what have been dubbed i3 (informed, intelligent, instantaneous) technologies and counter-stealth features. Released by the TRDI, the early examples of digital mock-up (DMU) concept designs from 2011 and 2012 resembled the Lockheed Martin F.A-22 Raptor and Northrop/McDonnell-Douglas YF-23, respectively. Dubbed 25DMU (from the Japanese calendar year Heisei 25, or 2013), the latest known example incorporates some of the design features of its predecessors. Following the RCS model, a combination of a model displayed at a TRDI event in 2007 and a 1/10th scale wind-tunnel model displayed in October 2012 had already provided heavy hints with regard to the direction the ATD-X’s configuration was taking, but closer inspection of the photos from July 2014 revealed more details of the definitive version. Salient points included the four-sided horizontal tail surfaces, which had been five-sided in the full-size mockup, and the rounder air intakes. As tends to be the case in Japan’s aerospace industry, the ATD-X represents a joint effort, with one prime contractor (MHI) mating major assemblies from other companies; the wings and both the horizontal and vertical tail surfaces were supplied by Fuji Heavy Industries (FHI).

Building on earlier research that was also conducted in the 2000s, the ATD-X will be used to investigate axisymmetric engine nozzle thrust-vectoring, achieved by three “paddles” mounted around each tail pipe, similar to the system used on the Rockwell X-31. An axis-symmetric thrust vectoring nozzle is also being developed for the full-scale production model. Ishikawajima-Harima Heavy Industries (IHI) is developing the 33,000lb-thrust XF5-1 low-bypass turbofan using ceramic composites-made turbine blades. The XF5-1 has its origins in basic research carried out by the TRDI from 1991. The first of four test-engines was delivered to the TRDI in 1998, but a full five-year prototype programme began only in 2015. All things considered, the ATD-X marks an important step in Japan’s efforts to retain and build on the expertise accumulated in the production of its own MRCAs. The JASDF’s definitive F-3 fifth-generation MRCA is due to enter service in 2035.

 

Meanwhile, technological challenges encountered in developing the 153kN-thrust Izdeliye 129 turbofan being developed by a consortium comprising Ufa Engine Industrial Association (UMPO), MMPP Salyut Moscow Machine building Production Enterprise and Rybinsk-based NPO Saturn; as well as the unreliability of the transmit-receive modules made of Gallium Arsenide (GaAs) for the Tikhomirov NIIP-developed N0-36 AESA-MMR have forced Russia’s air force to limit its orders for the Su-57 fifth-generation MRCA to only 12 units. All these MRCAs will be powered by 147kN-thrust Saturn/Lyulka 117S/Al-41F-1S turbofans, and be equipped with N0-35 ‘Irbis’ PESA-MMRs.

Here’s the UK government’s new Combat Air Strategy document:

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/725600/CombatAirStrategy_Lowres.pdf