The fourth fin, a vertical stabilizer, remains fixed.

As the helicopter accelerated, air started rushing ever faster around the vertical stabilizer, bullying it from side to side.

He hauled a hefty piece of the vertical stabilizer-sixpounds, he reckoned-tothe machine and jammed it into the gnashing teeth.

The Lilium does away with the sort of tools that conventional planes use to control their movement, including the vertical stabilizer, ailerons, or elevator.

The damage to the fuselage just in front of the vertical stabilizer appears to be significant, exposing the internal structure within the composite fuselage.

Solar Impulse engineers are assembling the horizontal and vertical stabilizers on the aircraft.

He stood beneath the gleaming hulk of a plane and its towering horizontal and vertical stabilizers.

The full-scale mock-up of the sleek aircraft, unveiled at the Farnborough Airshow, is Lockheed F-22 Raptor-esque, with twin engines and two vertical stabilizers.

A key challenger to Britain's monopoly in wings is Spain, where Airbus has commissioned the vertical stabilizers for the A400M military plane due in 2009.