A French-led effort to develop a stealthy unmanned combat air vehicle is set to move into high gear as engineers begin to prepare detailed definition of the Neuron demonstrator.

For the six partner nations, Neuron is a major attempt to explore what uses a UCAV capability might serve. For industry, it's seen as a vital effort to keep pace with the nearest competitors. Program planners acknowledge that similar U.S. and British undertakings might be further advanced (AW&ST Dec. 11, 2006, p. 35). But with military strategists everywhere still grappling with UCAV requirements, they are confident there's still enough time for Europe to be competitive. In fact, they are already eyeing an extension to the 10-year program to allow more potential uses to be explored.

Major design milestones lie ahead in the coming months. The ¬400-million ($524-million) undertaking--which kicked off in 2004 and contracted in February 2006--is intended to demonstrate vital technologies for a next-generation combat aircraft (manned or unmanned) and, perhaps more importantly, to show how such a program should be run.

In September, the program passed a first intermediate synthesis review--a milestone in the two-year feasibility phase that's about two-thirds complete. Midyear, managers expect to hold a launch design review, which will permit the project to move into the detailed design phase. Manufacturing is to begin in 2008, with first flight in 2011. Flight tests are expected to last 18 months.

Wind-tunnel testing of various airframe layouts have led to a slight tweak in the configuration and aerodynamic shape (AW&ST June 20, 2005, p. 33). Designers opted for a one-engine (versus two-engine) configuration and shifted from a cranked wing to a single-sweep mold-line. The straight-sweep configuration was deemed to have better controllability and stealth characteristics, although it offers a lower static margin.

High-speed wind-tunnel trials, to begin soon, will allow engineers to refine the current concept, labeled AP781-20, including a compromise between high- and low-speed performance characteristics. A final shape will not be frozen until 2008.

The vehicle is expected to be 9.3 meters (30.5 ft.) long and have a 12.5-meter wingspan--a bit shorter and wider than initially thought. Maximum takeoff weight will be 5,000-6,500 kg. (11,000-14,300 lb.). Top speed is Mach 0.85, and endurance is to be more than 12 hr. Composites will feature heavily in the design.

Neuron will have a fly-by-wire flight control system, four control surfaces and two weapon bays, each sized for a Mk. 82 bomb. It will feature an electro-optic sensor and a line-of-sight data link, but no synthetic aperture radar or radar warning receiver (although there will be provision for supporting a RWR). Avionics, hydraulics and electrical systems will be fully redundant to meet JAR 23 civil airworthiness requirements.

The six industrial partners--Dassault Aviation, Saab, Alenia Aeronautica, EADS CASA, Ruag Aerospace of Switzerland and Hellenic Aerospace Industry--have already assigned about 500 people to Neuron, including 100 or so on the physical design plateau here at Dassault headquarters. More than 1,000 employees will be working on the project by the time production is in full swing.

Some supplier decisions have been made. The aircraft will be powered by a Rolls-Royce/Turbomeca Adour 951 engine, also used by the Hawk trainer. Galileo Avionica will supply the electro-optical infrared sensor, with the aperture placed left of the nose-landing gear. Thales will provide the data link.