Passenger planes are being checked for ash damage to their engines before every take-off and after every landing at UK airports as part of increased safety measures, the National Air Traffic Services (Nats) confirmed yesterday.
Aviation experts predicted that damage to engines on those planes that fly through ash clouds will reduce the lifespan of aircraft.
Despite the go-ahead for the resumption of commercial flights last week, the Civil Aviation Authority (CAA) issued new safety guidelines to all airlines last Thursday laying out extra safety checks.
Last night the ash cloud was hovering around Iceland, but RAF Typhoon jet training flights stationed at RAF Coningsby, in Lincolnshire, were grounded last Thursday after the discovery of volcanic ash in their engines.
The Finnish Air Force released images last week showing damage to the inside of Boeing F-18 Hornet fighter engines that had sucked in volcanic dust, while last Monday US officials confirmed a Nato F-16 fighter plane engine had also been damaged.
The CAA and air traffic control services allowed the resumption of flights after hearing evidence from aero engine manufacturers that engine tolerance to volcanic ash could be increased from zero, albeit to a very low level.
Alex Bristol, Nats's general manager for strategy and investment, said: "The CAA was presented with scientifically backed evidence, rather than one or two flights which had been undamaged, that showed previous criteria which set the engine tolerance at zero was probably erring too far on the side of caution.
"There are some reports of increased wear and tear on aircraft. I would say they are more likely to shorten the lifespan of an aircraft. It's not going to be dangerous to flight."
But David Learmount, an independent aviation expert and a former pilot, said research was limited because previously pilots flew around volcanic ash: "Their experience [from scientific test flights] was universally benign. But did they get lucky? We don't know. What's more we don't yet know whether low level abrasion has affected the engine efficiency. An increase in fuel consumption for the life of an engine would be a high price to pay for an early return to the skies."
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies