Investigators believe the British Airways Boeing 777-200ER which
crashed at London Heathrow would have struck the ground earlier,
potentially colliding with the instrument landing system
antenna, had the pilot not partially retracted the flaps on
approach. The final report into the accident shows that the
aircraft's flaps were at 30° before ice flushed through the fuel
lines choked off the fuel flow to both engines. As the aircraft
descended to a height of about 240ft, the captain retracted the
flaps to 25°. The Air Accidents Investigation Branch concludes
that this enabled the aircraft to glide an extra 50m (160ft)
before touching down. "The action of reducing the flap setting
was prompt and resulted in a reduction of the aerodynamic drag,
with a minimal effect on the aircraft stall speed," it states. ©
Metropolitan Police ASU If the twin-jet's flaps had remained at
30°, the AAIB adds, it would have cleared the Heathrow perimeter
fence but landed before the ILS antenna, probably resulting in a
collision. "Th