Bell [TXT] unveiled the full-size mockup of its V-247 autonomous tiltrotor Sept. 25, and it is much larger than a scale-model suggests.
Just outside the company's booth at the Modern Day Marine in Marine Corps Base Quantico, Virginia, passersby kept up an audible chorus of surprise as each caught a first glimpse of the unmanned aircraft system (UAS), which is about the size of a UH-1Y Huey. It was designed that way for several reasons, Todd Worden, Bell's senior manager for advanced tiltrotor systems, told sister publication Rotor & Wing International.
The Bell V-247 autonomous tiltrotor was unveiled at Modern Day Marine, Sept. 25, 2018. Photo by Dan Parsons
"It's all about achieving range and payload and for that you need power and fuel," he said. "It's about the size of a [UH-1Y] Yankee for that reason. The fuselage is about the same size, but then you add the tiltrotor and it now provides a completely different, versatile capability."
The outline of a UH-1Y is painted as a shadow beneath the full-size mockup at the expo to show the relative size and how it will fit on Navy ships. The 247 was designed inside the "box" of a DDG hangar, which means it can fit on and inside just about any ship that can accept rotorcraft, Worden said.
All of the design parameters are aimed at meeting Marine Corps requirements for MUX, which stands for Marine Air-Ground Task Force (MAGTF) Unmanned Aerial System (UAS) Experimental. The Marines are in the market for a Group 5 UAS – think MQ-9 Reaper – capable of vertical takeoff and landing.
Size comparison with wings folded of the V-22 Osprey (L-R), the V-247 and the UH-1Y.
"We are pacing ourselves against the Marine Corps' mission requirements for MUX," Worden said.
That pace, so far, has been relatively swift for an aircraft development program thanks to the 247's older brother, the V-280 Valor. Having now flown 60 hours, the Valor provided much of the one-time engineering risk reduction work that ported directly into designing the 247, Worden said.
"All the work that went into the V-280, we are porting into the 247," he said. "We accomplished a lot of firsts with that aircraft, and now we don't have to do all those firsts on this aircraft. Every time the V-280 flies, we further reduce the engineering and development risk with this aircraft."
A single centerline Rolls-Royce 1107C – the same engine used in the V-22 – with bifurcated inlets and a single aft upward exhaust provides 7,000 shp to the two rotor nacelles. To maximize lift surface and thereby fuel efficiency and range, the wings continue past the nacelles and terminate in winglets while the V-280's nacelles are at the end of its wings. The outer wings swivel with the nacelle when the 247 transitions from vertical to forward flight.
Bell is advertising a long-range cruise speed of 240 kt with a 300-kt maximum, while best endurance speed is 180 kt. With two aircraft, Worden said the aircraft can sustain 24-hour on-station operations at mission-viable ranges, hence the "247" designation. Specifically, Bell is aiming for more than eight hours loiter time with a 600-pound payload at 450-nm mission radius.
It should have an internal mission payload capacity of 2,000 pounds and a slingload capacity of 9,000 pounds. That capacity is what will make the aircraft so versatile, Worden said.
"It is really a modular, open-architecture platform that can accommodate any weapon in the service's inventory or on hand for a particular mission," he said.
Two conformal belly pods can carry electronic warfare equipment or AIM-9X Sidewinder air-to-air missiles. The mockup has four underwing pylons with various configurations of Hellfire Missiles and Textron Fury glide bombs.
That modularity also may make the drone appropriate for other services, Worden said. Bell is closely following the Army's next-generation UAS program, for instance.
But the unveiling was tailored to the Marine Corps because it is in the market for a high-altitude, long-endurance drone that can launch from a ship, perform reconnaissance and relay communication to deployed ground forces for about $20 million per copy.
Other missions for MUX will include airborne early warning and electronic warfare. Offensive air support has been pushed to a secondary mission profile as the service begins to solidify its requirements.
The request for information (RFI) describes a fully autonomous air vehicle that can take off from and land on helicopter-capable amphibious ships or an austere 150-foot-by-150-foot landing zone. It should cruise at speeds of 200 to 300 kt with a full payload and stay on station at least eight to 12 hours at 350 nm mission radius. Unrefueled, it should have a range of 350 to 700 nm from the ship.
Fast is the name of the game for development and procurement, and the Marine Corps is prepared to move as fast as technology will allow, Lt. Gen. Steven Rudder said at a June industry day near Quantico. After an acquisition decision planned for fiscal 2020, the service wants a land-based early operational capability in within five years and a land-based initial operational capability two years later, with a sea-based IOC to follow.