The US Army is to continue refining concepts for the Joint Heavy Lift (JHL) aircraft, but has narrowed the candidate configurations from five to three. The large cargo rotorcraft will also get bigger, from Lockheed Martin C-130-sized to equivalent in capacity to the Airbus Military A400M.
Five concepts for JHL were studied under 18-month concept design and analysis (CDA) contracts that ended early this year. Bell Boeing worked on the Quad Tiltrotor, Boeing the Advanced Tandem Rotor Helicopter (pictured below), Frontier Aircraft the Optimum Speed Tilt Rotor, and Sikorsky the coaxial-rotor X2 Crane and X2 High Speed Lifter.
Boeing's Advanced Tandem Rotor helicopter
US Army Aviation Applied Technology Division project official Bruce Tenney says there is to be two more years of concept refinement work, but declines to identify which configurations have been selected for further studies. "We are in the process of finalising the statement of work and will go forward with three of them," he says.
The goal is to prepare for a competition in fiscal year 2009 to select one design for an experimental aircraft to be built and flown in the FY2010-14 timeframe to demonstrate that JHL is feasible. "We are updating the model performance specification and doing some more analysis on the operational and technical sides," says Tenney.
JHL is a large cargo rotorcraft that would carry medium-weight armoured vehicles around the battlefield. The baseline requirement for the CDA studies was to carry a Stryker or Future Combat Systems armoured vehicle over 460km (250nm), but design excursions looked at even larger aircraft. Other potential missions include long-range special operations and ship-to-shore transport to support seabasing.
"We are convinced JHL is technically feasible. Now we need to go conduct a near full-size experimental flight programme," says Tenney. "We now have a much clearer vision of the aircraft and part of what we need to do is resize the aircraft accordingly," he says. "The baseline was C-130-sized. Now the fuselage is larger than the C-130 and approaching that of the A400M."
The additional concept refinement studies will be funded in FY2008 and FY2009 by the US Army, "joint sources and other services", says Tenney. The initial capabilities document for JHL is being drawn up, and funding for the technology demonstrator will be sought on the FY2010-14 defence plan. The goal is to be ready to enter system development and demonstration in 2015, he says, for service entry around 2020.