An air safety expert has joined former chief of the defence staff in expressing fears that Russian aircraft could collide with civilian aircraft in UK airspace. Concerns have grown over the appearance of Russian long-range Bear bombers off Bournemouth and the coast of Cornwall.
On Sunday former armed forces head Lord Stirrup said: "We are seeing the possibility of mid-air collision not between, I think, RAF and Russian aircraft but between Russian aircraft and civilian aircraft increasing."
On Monday, David Learmount, operations and safety editor of Flightglobal publication, said the danger of such collisions existed, particularly as the Russian planes tended to switch their radio frequency identification transponders off on certain missions.
He went on: "There is a risk. Aircraft can be tracked through their transponders but it's unlikely that the Russians flying close to the UK would have their transponders on. This would mean the civil air traffic controllers at their Swanwick (Hampshire) headquarters could not track these Russian planes."
He said: "Our military should be able to track them but the risk of a collision exists, especially as these kind of Russian flights are growing in number."
Speaking about the Russian flights Lord Stirrup said: "They are becoming more aggressive. These aircraft - Russian Bears for example - are not going on these very flights simply as joy rides. They are mission rehearsals."
He continued: "These aircraft launch stand-off missiles against western targets and just as they used to do in the Cold War they are practising those profiles. They are testing us, they are testing our defences, they are testing our reactions and they are engaging to a degree in a game of chicken, and that's very dangerous."
A spokesman for British airline pilots' organisation Balpa said: "Pilots are concerned about these infringements and take confidence from the vigilance and swift response demonstrated by the RAF, supported by the UK radar infrastructure and incident protocols."
The following images provided by the MoD are of two Russian surveillance planes that were detected off the coast of Scotland in April 2014.