Britain changes flying rules in ash conditions

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Britain on Monday night introduced new rules which allow aircraft to fly through “medium density” ash clouds, leading the air traffic control service to ease restrictions on the UK airspace.
“Every leading player in aviation has been helping to build vast amounts of data about the effects of volcanic ash over the last month. There is mounting evidence that aircraft can fly safely through areas of medium density, provided some additional precautions are taken. This is now what has been agreed,” NATS chief executive officer Richard Deakin said.
Britain has now introduced a new fly zone, called Time Limited Zone, for areas of medium ash density to enable aircraft to fly. The Civil Aviation Authority in the UK had applied No-Fly Zones in areas of greatest ash density and Enhanced Procedures Zones in areas of low density in April during the first volcanic ash crisis. The change in rules came into effect from midday on Tuesday.
Aircraft and engine manufacturers, based on new research and analysis, have agreed that it is safe to allow operations in the new zone for a limited time at higher ash densities than is currently permitted, the CAA said.
However, to operate in the new zone, the airlines will need to present the CAA with a safety case that includes the agreement of their aircraft and engine manufacturers.
“Unprecedented situations require new measures and the challenge faced should not be underestimated. Firstly because the standard default procedure for aircraft that encounter ash, to avoid it completely, doesn’t work in our congested airspace. Secondly, the world’s top scientists tell us that we must not simply assume the effects of this volcano will be the same as others elsewhere. Its proximity to the UK, the length of time it is continuously erupting and the weather patterns are all exceptional features. “The answer can only come, therefore, from aircraft and engine manufacturers establishing what level of ash their products can safely tolerate,” CAA chief executive Andrew Haines said.
As a result of the change in rules, there are no predicted restrictions on UK airspace in the immediate future, NATS said. The met office on Tuesday defended it forecasts on the movement of volcanic ash cloud in the British airspace. “There was ash over the UK. Our forecasts are updated regularly and are based on a number of factors, including observations from space and inputs from our colleagues,” the met office said.