Bell V-247 Vigilant

The Bell V-247 Vigilant is a concept by Bell Helicopter to develop a large tiltrotor unmanned aerial vehicle.

Development
Bell created the V-247 to meet emerging U.S. military needs for a runway-independent Group 4 or 5 UAV to provide persistent support to ground forces while requiring less space to store and transport; Group 4 UAVs weigh more than 1320 lb and fly below 18000 ft, while Group 5 UAVs weigh the same but fly above 18,000 ft, such as the MQ-9 Reaper, RQ-4 Global Hawk, and MQ-4C Triton. It is named V-247 by the company because it is planned that a two-aircraft team can provide 24/7 intelligence, surveillance and reconnaissance (ISR) over a given area. The design uses tiltrotors to take off vertically and transition to high-speed forward flight, enabling performance unachievable with just rotorcraft or fixed-wing aircraft. It leverages technologies which Bell previously utilized for the V-22 Osprey and V-280 Valor for the Future Vertical Lift program, and the HV-911 Eagle Eye, another smaller unmanned tiltrotor dropped in 2008. The aircraft is capable of performing a variety of missions including electronic warfare, persistent fire support, airborne early warning (AEW), and resupply. Bell is particularly interested in the U.S. Marine Corps' Marine Air Ground Task Force – Unmanned Expeditionary Capabilities (MUX) concept to perform the tasks of MQ-1 Predator and Reaper aircraft while operating from amphibious assault ships to complement and escort the MV-22. The U.S. Army is also interested in runway-independent unmanned aircraft, and the Vigilant could be incorporated into manned-unmanned teaming (MUM-T) arrangements where helicopter pilots have the ability to control nearby drones from the cockpit using a tactical common data-link. A 1/8-scale model was unveiled on 22 September 2016, and the system could be ready for production by 2023. While Bell is funding the V-247 through its preliminary design phase, the company is searching for a customer, likely the USMC, to fund the follow-on design effort to incorporate specific requirements into the design.

Design
The V-247 Vigilant is designed to weigh 16000 lb empty and carry 13000 lb of fuel, weapons, and sensors for a maximum gross weight of 29000 lb, roughly three times the maximum takeoff weight of the MQ-9. While the V-22 and V-280 use two engines located within the tiltrotor pylons, the V-247 will have a single engine housed in the fuselage generating 5,000-6,000 shp (3,670-4,410 kW), about as much as the V-22's engines. Wingspan is 65 ft, just 1 ft shorter than the Reaper's, with 30 ft-diameter tilting rotors, 8 ft smaller in diameter than the V-22's. Like the V-280, it has a V-shaped tail and one long wing piece mated to the top of the fuselage as well as retractable tricycle landing gear. To enable size compatibility with U.S. Navy Arleigh Burke-class destroyer guided missile destroyers, the wing and rotors swivel along the 37 ft-long fuselage to have the same footprint as the UH-1Y Venom helicopter; two folded up V-247s can fit inside one C-17 Globemaster III transport aircraft. The aircraft aims to have a cruise speed of 250 knot, a top speed of 300 knot, and a service ceiling of 25000 ft, with a combat radius of 450 nmi and time-on-station of 11–15 hours while carrying a 600 lb payload. Range is 1400 nmi for 17 hours on internal fuel, and it has the capability for aerial refueling. The aircraft can support an internal mission payload of 2000 lb and can sling-load 9000 lb. The Vigilant is equipped with three internal payload bays, a centerline payload, and the capability to house up to two underwing pylons per side for various payloads including additional fuel, radar systems, LiDAR modules, sonobuoys, the Mark 50 torpedo, AGM-114 Hellfire, and Joint Air-to-Ground Missile (JAGM).