Bell reveals its 5-seat Nexus Air Taxi
Bell is a global helicopter leader and no stranger to the vertical takeoff and landing (VTOL) world. Bell is using its vast experience and knowledge from its first ducted fan aircraft, the Bell X-22, which first flew in 1966, to its experience with the V-22 Osprey tiltrotor, and the new V-280 Valor tiltrotor aircraft in making the Nexus VTOL aircraft. The CMV-22 Osprey is the US Navy version, CV-22 is the US Air Force’s version and the MV-22 Osprey is the US Marines’ version. It is interesting to note that during the Nexus programme, Bell has done extensive indoor and outdoor testing with ducted fans, from trying different blade sizes, using various fan speeds and much more. Bell has found that ducted fans reduce noise and increase the efficiency of the propellers.
On 25 April 2017, at the Uber Elevate Summit Bell (then ‘Bell Helicopter’) announced that the two companies would be working together to accelerate the eventual large-scale deployment of electric vertical take-off and landing vehicles (VTOLs) in order to fulfil their mission of providing a safe, reliable transportation service to everyone, everywhere. The vehicle is designed for urban mobility and can be used as part of the Uber Elevate concept including using vertiports or Skyports. CES is an annual trade show organised by the Consumer Technology Association and is held in January at the Las Vegas Convention Centre in Nevada, United States. This event typically hosts presentations of new products and technologies in the consumer electronics’ industry.
Bell says team Nexus consists of a partnership with Electric Power Systems (EPS energy storage systems), Thales (Flight Control Computer (FCC) hardware and software), Moog (flight control actuation systems) and Garmin (integration of avionics and the vehicle management computer). A full-scale demonstrator is expected soon with widespread entry into service scheduled for the mid to late 2020s.
Nexus 6HX
At CES 2019, Bell displayed its full-size Nexus 6HX design, a hybridelectric vertical take-off and landing (eVTOL) aircraft aimed at ondemand urban mobility. Nexus is a ducted fan hybrid-electric aircraft fully autonomous flight capable. It will convert from helicopter mode to airplane mode, just like Bell’s other tiltrotors. The Nexus 6HX has six large ducted fans for vertical and forward flight, three on each side of the fuselage, with a main eight foot (2.4m) high wing with a high rear stabiliser. The middle set of rotors are located on the ends of the main wing and the fans pitch from vertical to horizontal allowing vectored and forward thrust. Landing skids contain small wheels. Whilst the Bell patent includes two different versions, the
first that accommodates one passenger and a pilot, whilst the second accommodates one pilot and up to six passengers. The current version shows a ‘4+1’ configuration for a pilot and four passengers. Top speed will be 155 knots (288 km/h) with a range of 130 nm (241 km). It has a gross weight of 6,000 lb (2,720 kg) and will fit in 40 X 40 feet (12.2 m square) footprint.
Nexus 4EX
After showcasing its flying taxi last year, Bell returned to CES in January 2020 where it unveiled a full-scale reconfiguration of its aircraft. The new Nexus 4EX removes two rotor ducts and adds a purely electric propulsion option. The 7,000-pound (3,175 Kg) aircraft can fly at speeds up to 150mph and features Bell’s signature powered-lift concept with four tilting ducted fans that can be configured as hybrid-electric or all-electric. Bell expects that the 4EX would be capable of flying up to 52nm (97km) whilst carrying four passengers, plus a pilot. it will have a range of up to 60 nautical miles at top speed. The vision for the Bell Nexus remains the same, but by taking a mature system-level approach to design for an objective market vehicle, Bell believes this configuration unlocks a capable, certifiable and commercially viable aircraft.
The 4EX is designed for autonomous operation, but Bell is anticipating the need for a pilot on board until public acceptance of autonomous flight is secured. In terms of a timeline for a Nexus demonstrator vehicle, Bell is looking to have a certified system ready to serve the public in the next several years. The Nexus air taxi will coexist to move people, products and information across connected cities. The company is also working on a hybrid-electric variant of the 4EX to tackle longer flights. It will use a turbo-generator to charge batteries and power electric motors, whilst it will have a range of 130 nautical miles.
Bell is currently designing advanced manufacturing technologies, including 3-D printing and it is using augmented and virtual reality to ensure its factories are built as efficiently as possible for highrate production of these aircraft. Bell’s goal is to have the Nexus operational by 2025. Bell has also stated that besides ride sharing, the Nexus can also be used for emergency medical services, tourism, corporate use, cargo and military use.
Bell also announced the company will be in the business of running its own fleet management programme for Urban Air Mobility (UAM). Bell will be designing urban air mobility software, called AerOS, a comprehensive fleet management system (including aircraft health and charge status.) Bell recognises the complexity and efficiency of the physical parts and data sharing needed for a passenger and cargo UAM system to work safely without errors in an urban and suburban environment. This system will include aircraft needed for both passengers and cargo, the booking of the flights and cargo, flight operations, affordability of flights, quiet aircraft, eco-friendly aircraft (no pollution), certification of all the aircraft and systems, a better manufacturing process, maintenance and repair needed, using the best technology possible and integrating the entire system with data sharing, so it works.
Bell’s complete UAM system will use artificial intelligence to anticipate ridership demand allowing early positioning of aircraft to meet those UAM needs. It will also project maintenance servicing times and to efficiently fly the aircraft through air routes in urban areas, avoiding all obstacles, including other aircraft. Bell also plans to offer its UAM app to any other company to operate its own UAM flight services. Bell has a safety goal of 10-9 probability of failure, meaning that it has a statistical likelihood of only one failure every one billion hours of flight. This is the current safety standard used for commercial airliners. The safety of Nexus urban aircraft will be to such high standards that an emergency parachute is not needed for the aircraft.