The jet plane in which adventurer Steve Fossett hopes to fly non-stop around the world without refuelling has begun its test programme in California, US.
Fossett may get behind the controls in late April
The Virgin GlobalFlyer is going through a series of shakedown flights ahead of Fossett's record bid later this year.
Manufacturer Scaled Composites says the initial tests indicate the aircraft has excellent handling capabilities.
The single-engined plane has a wingspan of 34.5m (114ft) and will fly at speeds exceeding 250 knots (440km/h; 285mph).
The challenge to fly non-stop around the globe - a distance of about 40,000 km (25,000 miles) - without refuelling has been completed before, by the Voyager aircraft in 1986.
But that was a propeller-driven craft and carried two individuals. The Virgin GlobalFlyer is powered by a single turbofan Williams FJ44-3 ATW jet engine and has room for only one pilot.
Model 311, as Scaled Composites know the craft, is currently being put through its paces by project test pilot Jon Karkow.
Steve Fossett will not get behind the controls himself until he has finished his latest venture - to set a record for the fastest boat around the planet.
He is currently in the Southern Ocean. "He won't be back until the beginning to mid-April," said a Virgin GlobalFlyer spokesperson. "Once he is then all his efforts will be focussed on the plane."
The record attempt will originate from somewhere in the central US.
GlobalFlyer's route should take it across the Atlantic to the UK. From there the aircraft will go south to the Mediterranean and then route through the Gulf to Pakistan, India, China and Japan.
It will then cross the Pacific and head back to the launch destination. It is likely to fly over or near the following destinations: Montreal, Gander, London, Paris, Rome, Cairo, Bahrain, Karachi, Calcutta, Shanghai, Tokyo, Honolulu, Los Angeles.
The project is backed by Virgin Atlantic. The airline's boss, Richard Branson, is designated as the reserve pilot.