A new project to make sure horse riders can be seen from low-flying helicopters is being launched by RAF Benson, one of the country's biggest helicopter bases.

And to mark it, the Ministry of Defence is giving away free high-visibility kits for riders and their horses.

The joint project by the MoD and the British Horse Society was prompted by an accident in Lincolnshire three years ago when a woman was killed after her horse was startled by a low-flying helicopter.

RAF Benson commander Group Captain Duncan Welham, said: "We need to do low-flying training here in Oxfordshire to keep our pilots in tip top readiness. But we also realise that horse riders and helicopters sometimes need the same space.

"A survey done by our pilots and local horse riders has shown that the best way for a helicopter pilot to see and avoid riders is for the riders to wear high visibility kit."

He added: "We need the goodwill of people here and we hope this is one way of keeping it."

Graham Cory, chief executive of the British Horse Society, said: "The clear message is that a horse rider who can be seen in good time by a helicopter pilot can be avoided in good time."

He said the high visibility kits were also very useful for riders to be seen on ordinary roads and for them to be spotted from rescue helicopters if they were thrown and injured in open land.

Tom Watson MP, Under-Secretary of State for Defence, launched the campaign by handing over the first set of kit to Mr Cory. He said very few cases of helicopters frightening horses were recorded.

People can get a free set of the high visibility clothing from Modviz, Safety Department, The British Horse Society, Stoneleigh Deer Park, Kenilworth CV8 2XV.

And riders now have a free phone number 0800 515544 to check on whether low flying is scheduled in an area where they are going riding.