Aviation safety officials have begun investigating claims a pilot refused to land on the only open runway at Heathrow because its radar was out of order.

The pilot of a Qantas Boeing 747 coming from Singapore surprised air traffic controllers by approaching the airport at 0400BST on Saturday - almost an hour early, according to the Guardian newspaper.

Heathrow's southerly runway was still closed for overnight maintenance leaving the only available runway in the north of the airport.

But the pilot told controllers that, with the runway's electronic guidance system being replaced, he was not prepared to risk a manual landing due to too much cloud

Back-log

The pilot also turned down an offer to land from the other end of the runway as there were insufficient approach lights.

The paper claims that, in the end, airport staff had to rush to reopen the main southerly runway, moving vehicles off the tarmac and sweeping the surface.

By the time the jet landed, at 0450, a queue of other long-haul aircraft had banked up behind it.

A CAA spokesman said: "I can confirm that we are examining this incident but it looks at this stage as if there are no safety issues. That is our conclusion at the moment."

Tailwinds

The paper claims that airlines are not happy with the "inadequate" number of runways at Heathrow.

The airport handles 64 million passengers a year.

A spokesman for the pilots' union BALPA said strong tailwinds can often affect whether an aircraft arrives at its destination earlier than scheduled.

The union is also backing government proposals to create a third runway at Heathrow to cope with demand.