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Helicopter crash: strict rules govern London airspace Helicopter crash: strict rules govern London airspace
(35 minutes later)
Strict rules govern the flying of helicopters in central London, a stretch of airspace that some pilots described as among the most closely monitored in the world.Strict rules govern the flying of helicopters in central London, a stretch of airspace that some pilots described as among the most closely monitored in the world.
A "notice to airmen" was issued to just last week warning of a crane newly erected on the Thames skyline alongside St George's tower – the crane that the helicopter that crashed in Vauxhall on Wednesday is believed to have struck. A "notice to airmen" was issued just last week warning of a newly erected crane on the Thames skyline alongside The Tower – the crane the helicopter that crashed in Vauxhall on Wednesday is believed to have struck.
The tower and crane was reportedly hidden by cloud. The crane was reportedly hidden by cloud.
Battersea heliport, the heliport serving central London, is less than half a mile from the scene of the crash. Battersea heliport, which serves central London, is less than half a mile from the scene of the crash.
Helicopters are generally only permitted to fly on strict routes over central London, in the controlled airspace up to 2500ft (around 800m). Flights within the London Control Zone must get air traffic control clearance and comply with instructions from controllers. Helicopters are generally only permitted to fly on strict routes over central London, in the controlled airspace up to 800 metres (2,500ft). Flights within the London Control Zone must get air traffic control clearance and comply with instructions from controllers.
One pilot, Gary Slater, told BBC news that "it is a very controlled area, probably one of the safest in the world in my opinion". One pilot, Gary Slater, told the BBC "it is a very controlled area, probably one of the safest in the world in my opinion".
In certain restricted zones, including the City of London and around Hyde Park, only police and emergency services craft are routinely allowed to fly, although others – particularly broadcast helicopters – can also obtain permission to do so. The Vauxhall site appears to be on the borders of this zone. In certain restricted zones, including the City of London and around Hyde Park, only police and emergency services craft are routinely allowed to fly, although others – particularly broadcast helicopters – can obtain permission to do so. The Vauxhall site appears to be on the borders of this zone.
The CAA rules say the onus is on pilots to navigate by sight around built-up areas and to be sure of visibility. Witness reports from experienced pilots suggest that visibility around the St George's tower, still under construction, was only around 200m, with the summit and the crane that the helicopter is believed to have struck shrouded in cloud. The CAA rules say the onus is on pilots to navigate by sight around builtup areas and to be sure of visibility. Witness reports from experienced pilots suggest that visibility around The Tower, which is still under construction, was only around 200 metres, with the summit and the crane the helicopter is believed to have struck shrouded in cloud.
The CAA says helicopter routes have been selected to provide maximum safety by avoiding built up areas as much as possible. The CAA says helicopter routes have been selected to provide maximum safety by avoiding builtup areas as much as possible.
All helicopters flying in the area, the London Control Zone, are subject to minimum visibility rules. To minimise noise nuisance, pilots are told to fly as high as their air traffic control clearance and prevailing cloud conditions allow. Pilots are told to fly precise routes and avoid "corner cutting". All helicopters flying within the London Control Zone are subject to minimum visibility rules. To minimise noise nuisance, pilots are told to fly as high as their air traffic control clearance and prevailing cloud conditions allow. Pilots are told to fly precise routes and avoid "corner cutting".
Above all, normal rules of the air mean pilots should not fly "closer than 500 feet to any person, vessel, vehicle or structure".Above all, normal rules of the air mean pilots should not fly "closer than 500 feet to any person, vessel, vehicle or structure".
However, multi-engine helicopters are given more scope to fly away from the designated helicopter routes with air traffic control clearance. The Agusta 109, the model reported to have crashed, is a twin-engine helicopter.However, multi-engine helicopters are given more scope to fly away from the designated helicopter routes with air traffic control clearance. The Agusta 109, the model reported to have crashed, is a twin-engine helicopter.
A notice to airmen was issued on 7 January warning of a 770ft crane erected in Vauxhall, lit at night, as an obstacle on the City routes and approach to Battersea heliport.A notice to airmen was issued on 7 January warning of a 770ft crane erected in Vauxhall, lit at night, as an obstacle on the City routes and approach to Battersea heliport.