from BBC NEWS:
Police officers dead in air crash
Two men who died when their microlight aircraft was in a mid-air crash with a helicopter on Tuesday were off-duty Hertfordshire police officers.
One of the two, who were in their 40s but have not been named, was a trained microlight pilot.
The helicopter pilot has a fractured leg and his passenger minor injuries, following an emergency landing.
A Hertfordshire Police spokeswoman said on Wednesday: "I can now confirm that the two people who died in the incident were in the microlight.
"They were two men aged in their 40s and I can also confirm that they were two serving police officers from Hertfordshire Constabulary who were off duty at the time.
Villager Dennis Shorter, who lives 300 yards from the crash site, said: "A microlight came straight over the house, not at the normal height I'd expect to see one. It wasn't that high.
I didn't see the helicopter until I heard the bang. I looked up immediately and there was this microlight twisting about 10 or 12ft below the helicopter and it came down like a dead bird that had just been shot."
Senior local air accident inspector Brian Curtis said microlights had an impeccable safety record and he had no knowledge of a similar tragedy.
The helicopter was operated by Cabair, a company offering training and charter flights, which is based at Elstree Aerodrome, Herts.