thumb
In
aviationAviation is the activity involving man-made air-borne flying devices , including the people, organizations, and regulatory bodies involved with them.- History :...
, the term
climb refers both to the actual operation of increasing the altitude of an
aircraftAn aircraft is a vehicle which is able to fly by being supported by the air, or in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil An aircraft is a vehicle which is able to fly by being supported...
and to the logical phase of a typical flight (often called the
climb phase or
climbout) following take-off and preceding the cruise, during which an increase in altitude to a predetermined level is effected.
A climb is carried out by increasing the lift of
airfoilAn airfoil or aerofoil is the shape of a wing or blade or sail as seen in cross-section....
s (wings) supporting the aircraft until their lifting force exceeds the weight of the aircraft.
thumb
In
aviationAviation is the activity involving man-made air-borne flying devices , including the people, organizations, and regulatory bodies involved with them.- History :...
, the term
climb refers both to the actual operation of increasing the altitude of an
aircraftAn aircraft is a vehicle which is able to fly by being supported by the air, or in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil An aircraft is a vehicle which is able to fly by being supported...
and to the logical phase of a typical flight (often called the
climb phase or
climbout) following take-off and preceding the cruise, during which an increase in altitude to a predetermined level is effected.
Climb operation
A climb is carried out by increasing the lift of
airfoilAn airfoil or aerofoil is the shape of a wing or blade or sail as seen in cross-section....
s (wings) supporting the aircraft until their lifting force exceeds the weight of the aircraft. Once this occurs, the aircraft will climb to a higher altitude until the lifting force and weight are again in balance. The increase in lift may be accomplished by increasing the
angle of attackAngle of attack is a term used in fluid dynamics to describe the angle between a reference line on a body and the vector representing the relative motion between the body and the fluid through which it is moving. In general, the reference line could be any line on any arbitrarily shaped body in...
of the wings, by increasing the thrust of the engines to increase speed (thereby increasing lift), by increasing the surface area or shape of the wing to produce greater lift, or by some combination of these techniques. In most cases, engine thrust and angle of attack are simultaneously increased to produce a climb.
Because lift diminishes with decreasing air density, a climb, once initiated, will end by itself when the diminishing lift with increasing altitude drops to a point that equals the weight of the aircraft. At that point, the aircraft will return to level flight at a constant altitude.
Climb phase
The
climb phase, also known as
climb out, of a typical flight of an aircraft is the period during which the aircraft climbs to a predetermined cruising altitude after take-off. Depending on the aircraft, the altitudes involved, and other factors, this phase may last from a minute or two to half an hour or more. 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 climbIn aviation, a step climb is a gradual climb from one cruise altitude to another in fixed steps, intended to keep an aircraft flying at the most efficient cruise altitude possible.-Description:...
).
If a climb beyond the abilities of the aircraft is attempted, increasing angle of attack in the wings may produce a stall.
Aircraft also climb by entering 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
glidersGliding is a recreational activity and competitive sport in which pilots fly unpowered aircraft known as gliders using rising air to gain altitude or speed. The word soaring is also used for the sport...
attempt such climbs on a regular basis. A passive climb combined with an active climb can produce a higher climb rate than either method alone.
The opposite of a climb is a
descentA descent during air travel is any portion where an aircraft decreases altitude, and is the opposite of an ascent or climb. Descents are an essential component of an approach to landing...
.
“Normal” climb
In some jurisdictions and under some conditions, “normal” climbs are defined by regulations or procedures, and are used to develop
airwayIn aviation, an airway is a designated route in the air. Airways are laid out between navigational aids such as VORs, NDBs and Intersections ....
systems,
airspaceAirspace means the portion of the atmosphere controlled by a particular country on top of its territory and territorial waters or, more generally, any specific three-dimensional portion of the atmosphere....
s, and
instrument proceduresInstrument flight rules are regulations and procedures for flying aircraft by referring only to the aircraft instrument panel for navigation. Even if nothing can be seen outside the cockpit windows, an IFR-rated pilot can fly while looking only at the instrument panel...
. Normal climbs are simply standardized climb rates achievable by most aircraft under most conditions that are used as conservative guidelines when developing procedures or structures that are partially a function of such rates. For example, a normal climb of 120 feet per nautical mile might be assumed during the development of a navigational procedure or while defining airspace limits in airport terminal areas.