Smith's career began at hospital radio before joining BBC Radio 1 in 1975. In 1983, Smith took over the weekday lunchtime show and took on the Breakfast Show in 1986, succeeding Mike Read.
Mike founded Flying TV ten years ago and the company says his legacy will be FTV continuing to go from strength to strength."
Smith was a key figure in the early years of Comic Relief but largely stayed away from the limelight after a helicopter crash which injured both himself and Ms Greene in 1988. The qualified pilot and his then-girlfriend Ms Greene were injured when the helicopter he was piloting crashed in Gloucestershire.
Both passengers survived, although Ms Greene broke both legs and an arm, and Smith suffered a broken back and ankle. The Air Accidents Investigation Branch concluded that "... examination of the helicopter (including flight control, fuel, engine control, dynamic systems and the engine itself) revealed no failure or unserviceability that could have resulted in a loss of rotor speed".
More top news
Several injuries have been reported after a van has crashed into people in the Ramblas area of Barcelona.
John Underhill said geological changes 55 million years ago mean the UK's geology is unsuitable for shale oil and gas production.
Argos will have to pay an additional £1.5 million to staff they underpaid, a government investigation has ruled.