In pursuit of its Future Attack Reconnaissance Aircraft (FARA) aspirations, the US Army will fund a Competitive Prototyping (CP) program aimed at designing, building and testing two aircraft by 2023. MS&T “flying editor” Dim Jones checked out Lockheed Martin’s progress.
The most pressing Army fleet need is an OH58D Kiowa Warrior replacement, whose retirement has exposed a capability gap for an armed reconnaissance helicopter. This is part of a wider procurement of a family of Future Vertical Lift (FVL) aircraft in the 2030s or earlier, which will possibly also encompass medium-lift and attack replacements for UH60 Blackhawks and AH64 Apaches, a total of over 3,200 airframes. These disparate requirements have been referred to as FVL Capability Sets (CS) 1 to 3; FARA will be comparable in size to FVL CS1, a light-attack and scouting aircraft with a minimum payload of six passengers. The Army envisions “software automation to reduce pilot workloads... autonomous capabilities... able to team with unmanned systems... [in] an integrated air defense system breaching team.”
Timescales are tight. Currently the only rotorcraft with the performance and flight hours to meet CS1 are Sikorsky’s S97, Airbus Helicopter’s Eurocopter X3 and Leonardo’s tilt-rotor AW609. AVX Aircraft and L3 have partnered to submit a joint proposal, precise design as yet unknown, and Bell are expected to submit a design, also unknown. The Eurocopter X3 and AW609 were both designed for the civilian market, but could be adapted for military use (as was the Kiowa). By contrast, the S97 was designed specifically to meet the FVL CS1 vision, and builds on Sikorsky’s X2 technology; however, whereas the X2’s purpose was to prove the compound rotor design by achieving high speed in a straight line, the S97 is designed to be both fast and manoeuvrable. To this end, the Raider embodies a rigid-coaxial rotor system with a clutched rear propeller and fly-by-wire flight controls, allowing speeds in excess of 200 kts – a target which the prototype achieved last September – while maintaining the low-speed handling qualities and maneuverability of conventional single-main-rotor helicopters. The S97 is single-engine, weighs around 11,000 lb, and is about three-quarters the size of a UH60.
At the heavier end of FVL, the Sikorsky-Boeing SB1 Defiant, a derivative of the S97, is twin-engined and weighs around 30-40,000 lb. Expected to make its first flight this year, the Defiant will compete for the Army’s Joint Multi-Role Technology Demonstrator, going against the Bell-Lockheed Martin V280 Valor, an advanced tiltrotor first flown at the end of 2017. Lockheed Martin is working with Bell to integrate their Pilotage Distributed Aperture Sensor (PDAS) system on the V280. PDAS is the core of the future survivability suite, providing a 360-degree situational awareness sphere around the aircraft to pilots and crew. System installation and integration tests were conducted in 2018; flight tests on the V280, to capture imagery from a suite of integrated sensors, will follow shortly.
As part of the Raider development programme, Sikorsky – acquired by LM in 2015 – have developed an FVL Light Portable Full Motion Simulator (PFMS) which I visited at their Global Innovation Circle facility near Orlando; we were hosted by the System Architect, Dan Morrison, and the Chief Test Pilot of the Development Flight Center, John Groth. This device was designed, developed and fielded within 12 months, the aim being to bring hands-on experience of X2 technology. Lockheed will also use it to support R&D-related FVL capabilities.
The simulator is based on the S97, and features a high-fidelity visual dome, completely contained within a portable semi-trailer. The trailer also includes a display / briefing room, designed to be flexible with video screens easily configured to connect to many sources. The high-fidelity visual system has a 245o x 72o field of view and uses five Barco F70 projectors. The cockpit is spacious and comfortable, the controls comprise a conventional collective and a side-stick cyclic, and the front panel is a large area display. The simulator was easy to fly, with the disparities between this and a conventional helicopter largely eliminated by the flight control system and associated avionic programmes. In particular, the auto-hover and zero-visibility landing capability (brown-out, white-out or fog) was most impressive.
As someone who has spent a lifetime flying different aircraft, I would have appreciated the opportunity of a more in-depth briefing. However, I was conscious of the time constraints of this ‘flying visit’, and grateful to experience this developing technology.
Originally published in Issue 1, 2019 of MS&T Magazine.