30 APRIL, 2016 BY: JAMES DREW WASHINGTON DC
AVX Aircraft of Benbrook, Texas has responded to the US Army’s request for information on the smallest of five planned Future Vertical Lift (FVL) capability sets with two 7.5t (16,700lb) winged coaxial compound helicopter configurations that the company’s chief executive describes as vertical takeoff fighter aircraft for light reconnaissance, attack, assault and medical evacuation missions.
The baseline swept-wing, 13.4m (44ft) diametre rotor concept would be powered by two 3,000shp Improved Turbine Technology Programme (ITEP) engines and is designed to meet a demanding set of core requirements proposed by the US Army in its “Capability Set 1” RFI document. The requirements that emerged for that next-generation rotorcraft category required a more robust design than the 4.5t (10,000lb) light single that AVX discussed with the Army back in January for Capability Set 1 (CS1), prior to the 18 February RFI release.
AVX’s FVL Capability Set 1 concept for assault and security operations and medical evacuation – AVX Aircraft
CS1 sought information on aircraft concepts that could achieve speeds above 200kts (370km/h) with a 229nm (424km) range. An assault/security and medical evacuation variant must accommodate six fully-loaded 151kg (335lb) troops and a gun four 360° protection.
AVX chief executive Troy Gaffey tells Flightglobal at an Army Aviation Association of America conference in Atlanta, Georgia on 29 April that the company scrabbled to complete the proposal once the RFI was released since most of its work has focused on FVL Capability Set 3, which would succeed the Sikorsky UH-60 Black Hawk and Boeing AH-64 Apache.
The company came up with two variants with 912kg (2,010lbs) internal payloads – one with a retractable missile launcher for the attack/reconnaissance mission and another that can carry the six troops and be reconfigured with two litters for medical evacuation.
AVX’s FVL Capability Set 1 concept for armed reconnaissance and attack – AVX Aircraft
“I’d call it a vertical takeoff fighter airplane, because it’s intended to be flown at high speed off the deck at night,” says Gaffey. “You look at it, it’s going to have terrain avoidance radar, forward-looking infrared and all the bells and whistles with regard to weight, so the aircraft becomes large.
“It’s a fighter plane and it’s intended to fly in all weather and at night. They want an aircraft that can be reconfigured into a medivac or a troop carrier and that’s a little bit of a challenge because you’ve got to accommodate weapons, people and litters.”
The new design, which includes a swept horizontal tail with two centreline ducted fans, is a significant departure from the Bell OH-58-based compound coaxial Kiowa Warrior concept that AVX proposed for the Army’s now-defunct Armed Aerial Scout programme. Despite cancelling AAS in 2013 and replacing the OH-58 with AH-64 Apaches teamed with unmanned aircraft, the Army remains committed to introducing a new light reconnaissance aircraft.
AVX’s light single for FVL – AVX Aircraft
If the Army were to seek a lighter, less sophisticated aircraft than described in the CS1 document, AVX could propose the lighter single ITEP engine variant it has been considering. That compound coaxial design has a 12m (40ft) diametre rotor and 680kg (1,500lb) payload.
Sikorsky has been touting its S-97 Raider, which has rigid counter-rotating blades and a pusher prop, for that mission as well as Capability Set 1. Bell Helicopter has been exploring a tiltrotor solution.
Future Vertical Lift (FVL)
Future Vertical Lift (FVL) is a program to develop a family of military helicopters for the United States Armed Forces. Four different sizes of aircraft are to be developed. They are to share common hardware such as sensors, avionics, engines, and countermeasures. The U.S. Army has been considering the program since 2004. FVL is meant to develop replacements for the Army’s UH-60 Black Hawk, AH-64 Apache, CH-47 Chinook, and OH-58 Kiowa helicopters. The precursor for FVL is the Joint Multi-Role (JMR) helicopter program, which will provide technology demonstrations planned for 2017.
Three sizes were planned in 2009, then four and five (which may or may not be of the same design) are envisioned to replace 25 current rotorcraft types:
- JMR-Light: Scout version to replace the OH-58 Kiowa; introduction planned for 2030.
- JMR-Medium: Utility and attack versions to replace the UH-60 Black Hawk and AH-64 Apache; introduction planned for 2027–28.
- JMR-Heavy: Cargo version to replace the CH-47 Chinook; introduction planned for 2035, although Boeing expects 2060.
- JMR-Ultra: New ultra-sized version for vertical lift aircraft with performance similar to fixed-wing tactical transport aircraft, such as the C-130J Super Hercules and the Airbus A400M Atlas; introduction planned for 2025.
According to the U.S. House Armed Services Committee, three different configurations of JMR aircraft – a conventional helicopter, a large-wing slowed rotor compound helicopter, and a tiltrotor – were being studied as of April 2013.
AVX Aircraft proposed an aircraft with their coaxial rotor and twin ducted fan design that provides better steering and some additional forward power. Their JMR-TD is to be built at 75% scale. It is capable of flying at 230 kn (260 mph; 430 km/h), with 40% lift from the small forward wings and 60% from the 56-foot rotors. Half the drag of the design comes from the fuselage and half from the rotor system, so wind tunnel tests are aiming to reduce drag by a third. The rotor system has two composite-flexbeam hubs with drag-reducing aerodynamic fairings on the blade cuffs and the mast between the hubs.