Before the accident, Concorde had been arguably the safest operational passenger airliner in the world with zero passenger deaths-per-kilometres travelled; but there had been two prior non-fatal accidents and a rate of tyre damage some 30 times higher than subsonic airliners from 1995 to 2000. Safety improvements were made in the wake of the crash, including more secure electrical controls, Kevlar lining on the fuel tanks and specially developed burst-resistant tyres. The first flight with the modifications departed from London Heathrow on 17 July 2001, piloted by BA Chief Concorde Pilot Mike Bannister. During the 3-hour 20-minute flight over the mid-Atlantic towards Iceland, Bannister attained Mach 2.02 and before returning to RAF Brize Norton. The test flight, intended to resemble the London–New York route, was declared a success and was watched on live TV, and by crowds on the ground at both locations.