Fastest speed in a helicopter (FAI-approved)
Who
Derek J Clews, Derek J Clews, Derek J Clews
What
400.87 kilometre(s) per hour
Where
United Kingdom (Glastonbury)
When

The official FAI speed record for helicopters is 400.87 km/h (249.09 mph) and was set by John Trevor Eggington with co-pilot Derek J Clews, over Glastonbury, Somerset, England on 11 August 1986 in a Westland Lynx demonstrator.