climbing The
climb phase, also known as
climb-out or
initial climb, is the period during which the aircraft climbs to a predetermined cruising altitude after take-off. The climb phase immediately follows take-off and precedes the cruise phase of the flight. Although a single climb phase is typical, multiple climb phases may alternate with cruise phases, particularly for very long flights in which altitude is increased as the weight of fuel aboard decreases (see
step climb). As the climb progresses, the rate of climb decreases as thrust reduces due to reducing air density. A gradual climb improves forward visibility over the nose of the aircraft. Aircraft also climb when flying in a zone of rising air, but since such zones are unpredictable and inconveniently located, and since most are poorly adapted to passive climbs of this type, only
gliders attempt such climbs on a regular basis. == Normal climb ==