Two airports have been alerted after a giant robotic balloon escaped from a science centre in South Yorkshire.
Airports have been warned about the giant balloon
Staff at the Magna Science Adventure Centre, in Rotherham, were forced to inform aviation authorities after the "flyborg" floated off into the sky as it was being moved.
The 13-feet long airship can expand to four times its usual size as it flies, and could fly for a week before it deflates.
Both Manchester and Sheffield airports were informed of its escape.
The flyborg has a computerised brain which allows it to avoid obstacles.
A spokesman for Magna said: "Two technical staff were moving a flyborg - an artificially intelligent flying robot airship filled with conventional party-balloon gas - into the main Magna building.
"The airships, constructed of lightweight polymer film, were tethered all the time to the people moving them but they had to be untethered to take the flyborg through the visitor attraction's entrance doors.
"The two technicians held on to the airship's gondola but were surprised by a very strong freak gust of wind which ripped the airship out of their hands and sucked it up into the air, leaving them holding the gondola."
The airship, which is valued at £15,000, was designed by Professor Noel Sharkey,
a BBC Robot Wars judge, and his team at the Creative Robotics Unit at Magna
for indoor flying robot exhibitions.
Staff have offered a reward for its recovery.