The previously unknown US manufacturer American Dynamics has flown at least two versions of its developmental BattleHog close air support vertical take-off and landing unmanned air vehicle (UAV).

A basic version of the BattleHog tactical air vehicle made a 3min debut sortie on 19 January last year, or some 18 months ahead of the now-public version, the BattleHog 100X.

American Dynamics revealed the privately-funded development programme for a tactical and unmanned combat air vehicle version of the UAV at the Association for Unmanned Vehicle Systems International’s (AUVSI) Unmanned Systems North America conference in Orlando at the end of last month.

Stefan Amraly, company chief executive officer, says the development effort began in 2001 with the objective of creating a tactical UAV that could be used in both urban and forest terrains.

The current tactical demonstrator is powered by a Rolls Royce T63-A720 turbine engine; however the January 2005 version may have used a piston powerplant. Plans to swap to a turbine were solidified around December 2005, indicating a six month manufacturing period leading up to the second version’s first flight in July this year.

The company’s appearance at the annual AUVSI exhibition surprised established North American UAV manufacturers.

American Dynamics took the unusual step of assembling the vehicle inside a black cloth enclosure to prevent its being seen before exhibition opening. Those same screens were again erected to prevent viewing during its disassembly by three people after exhibition closure.

The firm has released few details about its background or its sources of expertise in aeronautical engineering. Amraly says the company currently employs 20 engineers and has over 300 contracts in place for subsystem and support work on the project.

American Dynamics has a history of involvement in the development of high speed marine vessel ride control and stabilisation technologies with applications for patents in this area secured in mid 2003. Amraly’s own business card cites a seventh floor office on Broadway in New York City. The same company name and address is identified in the current New York yellow pages business telephone directory as a home security and technology services consultancy.

Amraly acknowledges the presence of private investors in supporting the BattleHog development programme but would not be drawn on details. Speaking with Flight Unmanned he said that the company has deliberately kept a low profile and elected to reveal the UAV only because of current marketing requirements.

But he declined to identify specific UAV acquisition programmes being pursued by the company.

Some American Dynamics literature released at the AUVSI exhibition refers to BattleHog as an ‘advanced Tier II’ system, the same language currently used by the US Marine Corps and the US Navy to designate the capabilities of their common current tactical UAV requirements. A downselect for a demonstration system for the USMC programme is due at the end of this month.

The BattleHog 100X unveiled at Unmanned Systems North America carried a US Air Force logo on one of its two tail planes; however Amraly says this does not indicate sponsorship of the development programme.

While no location details for the January 2005 flights have been released, Amraly says that the July flights were held in the vicinity of Eagle’s Nest airport in New Jersey, near Atlantic City. Flight Unmanned has found that American Dynamics signed a lease to purchase deal for the Eagles Nest airport on 10 April this year.

Eagles Nest airport is 20km (12mi) from Lakehurst Naval Air Station, 33km from McGuire AFB and 7km from the US Army’s Fort Dix facility.

Amraly says the July flights were observed by potential military customers but again declined to provide specifics. The July flights included taxi, engine run-up, software testing and hover.

BattleHog 100X has a span of 5.2m (17ft) and a length of 3.8m. Maximum take-off weight is put at 1,450kg (3,200lb). The primary lift system is a duct mounted twin fan system with each mounted on a swash plate mechanism. Directional control is achieved by repositioning the fan angles within the duct to create vectored airflow. There are no vector nozzle systems however. American Dynamics has patented the system under the name “High Torque Aerial Lift” or HTAL.

Consideration is being given to replacing the existing Rolls-Royce engine with a Pratt & Whitney PW206 in the demonstrator says Amraly, to provide additional power and performance.

The primary aircraft sensors would comprise a FLIR Systems combined infra-red and daylight camera system housed in an off-centreline, under fuselage turret. Miniature synthetic aperture radar is an option the company says, as would be communications relay payloads. Narrow band satellite communications links are proposed as an option for extended beyond line of sight operations.
The bulk of the central fuselage area around the duct fan assembly is used as a fuel tank, with the UAV also featuring wet wings. The UAV would have an endurance of above 8h and would cruise at 180kt (330km/h).

In forest environments BattleHog 100X would capable of flying below treetop level says Paul Vasilescu, American Dynamics technology development director, with nap of the earth and terrain-following flight achieved using radar. The primary terrain avoidance sensor will be a modified Raytheon radar derived from a system already carried by the Lockheed Martin F-16 fighter he says, but declines to provide specific details on type. The radar would be housed in the aircraft nose, meaning an antenna height of 200-250mm (8-9in).

Vasilescu says the guidance and flight control systems for the UAV are being developed in-house and will include artificial intelligence capabilities to ensure the air vehicle is “very autonomous”. As well as terrain following radar the UAV will carry its own meteorological sensors and be able to make its own decisions about flight paths and re-routing in a dynamic manner. He says that the company disregards waypoint based navigation as an element of “genuine” autonomous capability.

A typical system would comprise three air vehicles, a ground control station and datalinks.

In its fire support role the UAV would primarily carry two Lockheed Martin AGM-14K Hellfire missiles mounted on pylons attached to the main undercarriage doors, and a M134 7.62 calibre minigun. Alternate weapons could include Hydra-70 folding fin rockets.

The all composite airframe is reinforced with Kevlar and is designed to be able to absorb 7.62mm rounds at a distance of 50m (165ft) says Vasilescu. The airframe should also be able to withstand near misses from rocket propelled grenades he says. Avionics bays have been mounted in the upper forward fuselage to minimise the risk of damage from ground fire.

The retractable undercarriage is heavily reinforced to support forced landings. Amraly says the company has spent “millions of dollars” on this part of the development effort: “We need the landing gear to survive”.

American Dynamics plans to spend the next 12 months refining the demonstrator, with this including demonstrating forward flight and manoeuvring modes, and “perfect the hover modes” says Vasilescu. A shipboard landing demonstration is under consideration, with this potentially using the US Navy’s UCAR landing system.

Other programme elements include a planned demonstration of the compliance of the ground control station with NATO Stanag 4586 architectures, and potential integration of tactical common data link (TCDL). Talks are underway with both Cubic and L3 on options in this regard Vasilescu says.

The forward programme also includes a desire to demonstrate target location, designation and weapons release, with this again potentially part of the next 12 months of activity says Amraly.

The planned larger unmanned combat air vehicle variant, designated BattleHog 350X, is now in manufacture and will make its debut flight in the spring of 2008 says Amraly. The UAV will support low-observable features and is intended to be capable of both land and maritime operations.

BattleHog 350X will use a single afterburning turbofan to drive twin lift fans, again using the HTAL system, mounted in a 40ft wing. The UCAV would have a low profile V-tail but as with BattleHog 100X, would rely on HTAL for directional control rather than use control surfaces.

It would have a maximum take-off weight of 16,800kg, with payload placed at 4,500kg. The air vehicle would have a dry weight of 6,800kg. The bulk of the airframe will use carbonfibre and Kevlar composites, with titanium structural reinforcements.

Weapons load is expected to include carriage of J series guided bombs and the Raytheon AIM-120 AMRAAM missile, carried in internal bays, and a 20mm machine gun.