The V-280 Valor is Bell’s vision of future military aviation. Photo credit to Bell Helicopters.
The helicopter is one of the key weapons systems in modern war. It has dozens of roles, right across the entire spectrum of warfare. In heavy metal conventional battles light, agile scouts probe ahead of advancing armoured formations to locate enemy positions, while attack helicopters ambush hostile tanks and act as a rapid counter-penetration reserve. Anti-submarine helicopters give every frigate the ability to search out and destroy subs over thousands of square miles of ocean. Special forces can be carried in at low level and inserted behind enemy lines. In counter-insurgency warfare transport helos let small forces establish a presence over wide areas while avoiding the risks of IED-infested roads. Able to loiter – or even land – in one spot for hours then move rapidly across miles of battlespace, or land troops precisely on target without the risks of parachuting, they give commanders a range of valuable capabilities.
Helicopters have problems, though. They’re generally not all that fast, with a typical transport model cruising at around 150 knots against the 300 knots or more of a fixed wing transport. Relying on rotors for lift makes them inefficient; high fuel consumption cuts down on range. They’re also noisy and vulnerable to ground fire, especially as they can’t climb very high; few helicopters can break 20,000 feet, and older models often struggle to get much past 15,000. Hot weather brings them down even lower, as warmer air is less dense and their rotors struggle to generate lift.
What commanders really want is a machine with the flexibility of a helicopter but the performance and reliability of a conventional light transport. Bell and Boeing have attempted this with the tilt-rotor V-22 Osprey, a medium-lift transport with two large props that act as rotors for vertical takeoff and landing, but pivot forwards for conventional flight. Capable of carrying 20,000 pounds of cargo or 24 troops, and armed with a variety of machineguns as required, it has now replaced helicopters in several roles with the US Air Force and Marine Corps. So far 141 have been delivered and the total order is for 458, with 360 going to the USMC and the rest split about evenly between the USAF and Navy.
The problem with the Osprey is that it’s a large aircraft, not suitable for many helicopter missions, and it’s also the first of its kind. The V-22 project has been running since 1981 and the first flight was in 1989; by the time it entered service in 2007 it had already been overtaken by technology. While the Osprey order will cover the USMC’s assault lift requirements and specialist roles in the USAF and Navy, it’s not really an option for the next generation of helicopters. Instead the Pentagon is running a programme called Future Vertical Lift. This is aimed at developing a family of machines capable of replacing the UH-60 Black Hawk as the standard utility helicopter, as well as the heavy-lift CH-47 Chinook and even the AH-64 Apache. There’s nothing in the project to say it has to be a tilt rotor – it just has to meet the performance criteria – and most of the candidates are ducted fan or helicopter-type designs. Bell are going with the experience they’ve gained from the Osprey, though, and plan to enter the tilt-rotor V-280 Valor.
At first glance the Valor looks like a smaller, more modern Osprey. It has the familiar wings and large prop-rotors, although in this design the engines don’t move during the transition between vertical and conventional flight; only the gearboxes and props themselves have to tilt. A V tail and full fly by wire make for excellent handling and the tilt rotor design makes it the entrant most likely to meet Future Vertical Lift’s ambitious 300 knot speed requirement.
Future Vertical Lift is looking at four sizes – Light, Medium, Heavy and Ultra – and Bell’s proposed demonstrator seems to fit in the Light category. With a proposed capacity of four crew and 11 troops it’s about equivalent to a Black Hawk, but as the Osprey – able to carry 24 troops – shows, the basic concept can be scaled up. That might not be so easy with the more helicopter-like designs from Boeing and others. The demonstrator will have a carbon-core wing and composite fuselage, and Bell say it will cruise easily at 280 knots and have a combat range of between 500 and 800 miles. Retractable undercarriage and a streamlined airframe maximise performance and fuel efficiency, and six foot wide doors on each side of the cabin will make for easy loading, stretcher embarkation and mission package installation. Bell’s concept drawings also show it fitted with pylons for rocket pods and what look like small diameter bombs.
The V-280 Valor is up against stiff competition from companies like Eurocopter and a Boeing-Sikorsky joint entry, but with the Osprey at last proving itself in service it could look like a low-risk option for the US military. It also promises fixed-wing levels of flight performance without compromising its vertical take off and landing ability. Bell have worked to make the Valor easy to maintain from austere fields, making it especially attractive to army aviation units, but the same features also translate into low operating costs for the other services. When the Future Vertical Lift programme reaches the flight test stage in 2017, and the real competition kicks off, this new Bell design will be one to keep an eye on.