Solar plane's night flight postponed by technical problem

A pioneering attempt to fly an experimental aircraft, Solar Impulse, through the night powered by nothing but the sun has been postponed due to a technical problem, organisers said Thursday.

"A failure occurred in a critical piece in the plane," Swiss adventurer Bertrand Piccard, the venture's founder and previously the first balloonist to circumnavigate the globe, said.

"We have taken the decision to postpone the takeoff to another day," he told a press conference and hour before the flight had been due to set off in near perfect weather conditions.

His spokesman told AFP that he was referring to a transmitter on the high tech aircraft which broke down on Wednesday night.

"It's a big disappointment for us," said Piccard, as gloomy faced team members looked on.

"Up to now I have to say in seven years we had no setbacks, everything went very well," he added.

"A few days ago we were discussing until when everything will go very well; well, the answer is, it was yesterday evening."

The ultra-light aircraft, flown by joint founder Andre Borschberg, had been set to take off from the Payerne airbase in Switzerland early Thursday and then fly for 25 hours through the day and the night.

The single seater clad with solar panels, which weighs little more than a saloon car but bears the wingspan of an Airbus A340 airliner, has completed 10 test flights since it first hopped along a runway seven months ago.

It has stayed aloft for up to 14 hours in daylight, with the most recent test flight just days ago.

Piccard said he did not know when they would be able to make the next attempt at a historic round-the-clock flight, which also depends on absolutely clear and stable weather condition, as well as long summer days and short nights.

"I hope it will be as soon as possible because the window to make the flight will end by the end of July beginning of August," said the Swiss explorer.

"We are under stress and we hope we'll make eveything work," he added.

The historic attempt is being monitored by the international aviation federation (FIA).