It averaged 25.6 kilometres per hour ( 15.9 mph ) , over a length of 145 metres ( 476 ft ) .
Snowbird flew for 19.3 seconds in a straight - and - level powered flight run under human power alone .
Snowbird averaged 25.6 kilometres per hour ( 15.9 mph ) , over a length of 145 metres ( 476 ft ) .
Snowbird flew for 19.3 seconds in a straight - and - level powered flight run under human power alone .