This sounds like a freak accident, and I am not aware of anything like this ever happening in the UK before.
Early indications are that the helicopter, a twin-engine Agusta 109, clipped a crane and then crashed into Wandsworth Road, which is close to the river.
How could this have happened?
First, a twin-engine helicopter can fly on one engine. A double engine failure is extremely unlikely, unless the helicopter ran out of fuel. However the fire in Wandsworth Road looks as if it is fuel fed, so that is unlikely.
More likely is that the pilot didn’t see the crane as he was descending to land at the heliport in Battersea. This morning’s weather may have reduced visibility and created a low cloud base. The crane was also in an unexpected position.
There are strict Civil Aviation Authority rules for pilots about flying in cloud and reduced visibility. All helicopter flights in the area of the accident have to comply with visual flight rules, keeping clear from the cloud and in sight of the ground (or river) and at an airspeed appropriate to the conditions. The National Air Traffic Service has published a notice to pilots about this very crane.
It states that between January 7 and March 15 there is a high-rise jib crane within one mile of the GPS location given up to a height of 770 feet above sea level. This crane height is above the normal height of a helicopter when descending into the Battersea heliport.
There have been lots of cranes in this area over the years, and pilots have become used to avoiding them. So questions will be asked about the position of the crane’s jib at the time of the accident — was it out over the river? There will also be questions as to whether such a high crane should have been allowed so close to the heliport.
My guess (and it is only a guess) is that the pilot simply didn’t see the crane in the reduced visibility and cloud base conditions, especially if it was over the river.
As with all aviation accidents, people want an instant answer, but all the facts and details need to be looked at calmly by the air accidents investigation branch and this takes time.
Jeremy James is secretary of the Helicopter Club of Great Britain and a commercial helicopter pilot.
