The passenger awaiting the helicopter in the fatal Vauxhall crash suggested to the pilot he should not take off due to freezing fog, investigators have revealed.
Transcripts released by air accident investigators also show the pilot was in contact with air traffic controllers up until seven seconds before his helicopter collided with a crane.
In the last moments of the conversation between Pete Barnes and the controllers, he was cleared to divert to Battersea heliport, before he turned the helicopter and struck the crane above a tower shrouded by fog, just over 200m above the south bank of the Thames.
Barnes, a pilot with decades of experience, had been flying from Redhill in Surrey to Elstree in Hertfordshire, but requested to land at Battersea because of the bad weather.
Barnes, 50, died from multiple injuries, and a pedestrian, Matthew Wood, was also killed as the fuselage of the twin-engine Agusta 109 helicopter plunged to earth on Wandsworth Road. Several other people suffered serious injuries.
National Air Traffic Services (Nats) said in a statement last week that the pilot had "received a service" earlier in his journey but was not in contact at the time of the crash. Records now show that the call only ended seconds before.
On Wednesday Nats said the "facts remain that he was not in contact with controllers at the moment of the crash".
According to the initial findings of the report, the client at Elstree twice called Barnes saying that freezing fog meant he should not try to collect him. At 7.29am Barnes texted the client to say: "I'm coming any way will land in a field if I have to."
At 7.55am he texted the helicopter operator at Redhill: "Can't get in Elstree hdg back assume clear still."
The helicopter came under radar control when it entered the controlled airspace above central London at 7.55am. A minute later, the pilot asked to divert to Battersea heliport.
At 7.59:10am the controller said: "Rocket Two, yeah Battersea's diversion approved. You're cleared to Battersea."
Barnes replied: "Lovely thanks Rocket Two".
The controller continued: "Rocket Two contact Battersea one two two decimal niner."
Barnes signed off: "Two two nine, thanks a lot."
The call ended at 7.59:18am, when the helicopter was around 150m south-west of Vauxhall bridge. It began to turn right, and seven seconds later hit the crane.
The impact caused debris and fuel to spread over several streets below, with rotor blades smashing through the windows of a nearby building and the gearbox striking a van in a nearby flower market.
David Learmount, operations and safety editor at Flightglobal, said the interim report should end a lot of speculation about system failures, although a full bulletin and conclusion from the AAIB is some months off. He said: "He was flying visually. The story of the accident is he didn't see it. Visibility was bad. The crane was lit.
"He was trying to carry out a very, very difficult task in very, very difficult conditions. The question is why did he not see it. Was he not looking at that direction or was it unseeable because of fog?"