Experts claim radio and fog to blame for London helicopter crash - The Independent

Aviation experts said the location of the collision, which took place in low cloud close to Vauxhall Bridge, was the point at which pilots approaching to land at the London Battersea Heliport were asked to switch frequencies to contact air traffic controllers.

Pete Barnes, a veteran pilot with more than 20 years' flying experience, had requested at short notice to divert from his intended route between Surrey and Hertfordshire so he could land at the heliport some two and a half miles from the crash site, close to a railway bridge.

Investigators from the Air Accident Investigation Branch are trying to establish what caused the eight-seater AgustaWestland 109 to clip the crane attached to the side of the St George Wharf tower, despite rules requiring aircraft to stay at least away 500ft from all structures.

Mr Barnes was flying in foggy conditions after taking off at 7.35am from the aerodrome at Redhill in Surrey, and requested via air traffic controllers at Heathrow to change route to reach the heliport, which operates its own air traffic control zone over a specified radio frequency.

A spokesman for the London Battersea Heliport, which yesterday re-opened after the crash, said it had received a request from Heathrow's controllers to accept the helicopter but never made contact with the aircraft.

David Learmount, operations editor of aviation website Flightglobal, said a small change in weather conditions, which are believed to have worsened around the time of the crash, could have been enough to "trap" the pilot as he tried to navigate a route to make a safe landing.

He said: "Weather will turn out to be the key issue. When you fly in marginal conditions it only needs a little dip in what you were expecting and you're pretty much trapped. He probably did not see the crane until it was too late. Sometimes even bright lights are difficult to see in foggy conditions."

The partner of Mr Barnes, 50, said the pilot would have instinctively tried to do everything possible to minimise casualties as his helicopter plunged to the ground. The second fatality in the accident, 39-year-old Matthew Wood, was struck by debris as he walked to work. Scotland Yard said it was a "miracle" that the outcome of the crash was not far worse.

Rebecca Dixon, who survives Mr Barnes along with their two children, Freddie, eight, and 12-year-old Alexandra, told the Evening Standard: "Obviously he would have been frantic and the lives of others would have been at the forefront of his mind. It sums up the man. I find it very comforting and so do the children."

The family of Mr Wood, a manager for pest control firm Rentokil, said he had been killed because he was determined to turn up early for work. His brother Darren, 35, said Matthew had not been due to start work until later but always arrived early at the office.

He said he texted Matthew shortly before 8am reassuring him about the wellbeing of his 11-month-old nephew, who was in hospital, and Matthew replied saying: "Good news."

Mr Wood said: "He was a very family-oriented guy and he doted on his nephew. You will never find a bad word said about him."