London Air Ambulance founder Alastair Wilson retires

They help save lives and can get to anywhere in Greater London within six minutes, but 25 years ago London's Air Ambulance did not even exist except as an idea in the mind of A&E consultant Alastair Wilson.

He helped set up the service but is now retiring after 30 years at the Royal London Hospital.

BBC London's Karl Mercer caught up with him for one last flight.