Ruag Aerospace hopes to have its new Super Ranger UAV ready for its debut flights by early 2008 with manufacture of a prototype planned for the second half of this year.

The new UAV is an outgrowth of the company’s existing Ranger series but with significantly increased payload and 20h endurance, as well as improved signature qualities.

Super Ranger development was initiated in 2005 in response to the perceived shift of the tactical military UAV market away from existing platforms in the basic Ranger class according to Josef Zemp, head of the Swiss-based Ruag Aerospace project team for the new aircraft.

Speaking at the Unmanned Vehicle Systems International UAV 2007 conference in Paris 14 June Zemp said that the new system “nearly gives you the performance of a medium altitude long endurance system but at the same life cycle cost like a small tactical system like Ranger. We think it is a good mixture in between.”

Development was launched at the end of 2005, with the design phase giving priority to reduction of life cycle costs as a whole, and to ensure that the new airframe would be capable of being certified under the evolving European airworthiness codes for UAVs, including the new Stanag 4671.

The company also wanted to expand the performance envelope of the new UAV, as compared to Ranger, in difficult environmental conditions such as icing and electrical storms. Zemp told the conference this has seen the integration of a pneumatic de-icing system and reinforced propeller, and a lightening strike protection system.

Preliminary design was completed midway through last year. Zemp said that compared to the original development plan “we are a little bit behind in mid 2007. So we are short before starting manufacturing a prototype and first flights are scheduled for early 2008.”

Super Ranger has a span of 9.48m (31ft) with the wing using a high aspect ratio profile coupled with what Zemp called a “smart flap system that enables the Super Ranger to reach a quite low stall speed - it is a kind of slotted flap”. The UAV has an all up length of 7.11m (22.33ft) and a height of 1.5m (4.92ft).

Super Ranger use a twin boom and pusher propeller configuration with power to be provided by a 4-cylinder 4-stroke, fuel injected engine. The aircraft will hold 190lt of fuel with a single integrated tank spread between the central fuselage and in-board wing.

The new UAV will loiter at 60-70kt and have a dash speed of 130kt. Its ceiling is projected at around 22,000ft. Maximum take-off weight is placed at 500kg (1102lb), including a 150kg (330lb) payload. The aircraft will have two sensor bays in the fuselage, with the forward space housing an EO-IR turret and the rear synthetic aperture radar. The UAV will also have dedicated stations on the wings for electronic warfare sensors. A piloting camera will also be carried on the tail plane tip.

The production Super Ranger will have the option of a nose mounted satellite communication capability with Zemp showing indicative drawings of a conformal radome above the aircraft nose to hose a steerable dish. When fitted the UAV would have an operational radius of 1300km (807 mile) from its operator station compared to a radius of 200km (124 mile) for the basis system equipped with standard line of sight datalinks.

Low observable features on the Super Ranger include a shaped fuselage to reduce corner reflections along with canted tail planes said Zemp, and infra-red suppression measures.

Work on reduction of the UAV noise signature stems was partially prompted by complaints from Swiss communities about military operated aircraft being used in homeland security roles. Swiss authorities regularly fly their existing Ranger systems over populated areas to support border surveillance operations. Zemp said that “especially during night time, while loitering, the engine noise is a big problem”. The Super Ranger noise signature is currently forecast at 68dB with ongoing work expected to take this below 65dB.

A retractable tricycle undercarriage has been included with this to incorporate a built in skid system to allow for operations on unprepared fields, snow and ice. However the UAV will also retain a catapult launch option says Zemp, using the same equipment as designed for Ranger.

The current production Ranger has a span of 5.71m (18.73ft), a length of 4.66m (15.29ft) and 285kg (628lb) maximum take off weight. It carries a 45kg (99lb) payload and can fly for 8h.