Flight AC991 is being operated as part of ICAO's Flightpath to a Sustainable Future.

ENGADGET: Air Canada embarks on its first biofuel-powered flight from Toronto to Mexico City

Transport Secretary Justine Greening - whose Putney constituency is on the Heathrow flightpath - has been a vehement campaigner against a third runway at the airport.

BBC: Heathrow third runway rethink urged by Tory MP