They change the surface area of a wing and provide a plane with more lift at a lower airspeed.

"But they'll give us some breathing room now, and the lower airspeed gives us some more time."

This happens at low airspeeds or during steep climbs.

An environment of low airspeed, and a demand for power.

Higher or lower airspeeds are obtained with the cyclic pitch control just as in normal flight.

The resulting mean thrust line could thus be varied to maintain controlled flight at low airspeeds.

At low airspeeds, the control surfaces became ineffective and could readily lead to loss of control, particularly during landing.

The glider was designed to fly at low airspeeds.

The critical angle of attack in steady straight and level flight can be attained only at low airspeed.

Many airfields operate a special pattern for helicopters to take account of their low airspeed.