Helicopters

Ships and helicopters left for the spacemen's rescue.

News stations use helicopters to report on traffic.

Medical helicopters take very sick people to hospitals.

In helicopters, the cyclic controls the tilt of the main rotor, producing pitch and roll.

In helicopters, yaw is controlled through the pedals, which alter the angle of attack of the tail rotor blades.

Tom could hear helicopters overhead.

São Paulo has the second largest fleet of helicopters in the world, behind New York, which has 420 helicopters in the whole of the city.

We heard the sound of helicopters overhead.

We could hear helicopters approaching.

How do helicopters fly?