Editing Climb (aeronautics)

{{short description|Flight maneuver}}
[[image:Iberia Airbus A321-200 (EC-ILP) departs London Heathrow 11Apr2015 arp.jpg|thumb|An [[Iberia (airline)|Iberia]] [[Airbus A321]] on the climbout from [[London Heathrow Airport]]]]

In [[aviation]], a '''climb''' or '''ascent''' is the operation of increasing the [[altitude]] of an [[aircraft]]. It is also the logical phase of a typical flight (the ''climb phase'' or ''climbout'') following [[takeoff]] and preceding the [[Cruise (aeronautics)|cruise]]. During the climb phase there is an increase in altitude to a predetermined level.<ref>{{cite book
|title=Federal Aviation Regulations/Aeronautical Information Manual 2008
|year=2007
|edition=2008
|publisher=[[Federal Aviation Administration]]
|isbn=978-1-56027-655-5
|page=944
}}<!--|accessdate=2009-02-06-->
</ref>
The opposite of a climb is a ''[[Descent (aircraft)|descent]]''.

== Climb operation ==

A steady climb is carried out by using [[excess thrust]], the amount by which the thrust from the power plant exceeds the drag on the aircraft.<ref name=LJC>[[L. J. Clancy]] (1975): ''Aerodynamics''. Pitman Publishing Limited, London, {{ISBN|0-273-01120-0}}</ref>{{rp|§ 15.1}} The aircraft will climb steadily until the excess thrust falls to zero.<ref name=LJC/>{{rp|§ 15.8}} Excess thrust might fall to zero as a result of the pilot's deliberate action in control of the output of the engines, or as the engines' response to reducing air density.

== Climb phase ==
[[Image:ENTERAIR6-SPENB.jpg|thumb|right|A [[Boeing 737]] 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.<ref>{{cite journal|title=Phase of Flight|journal=NTSB|date=April 2013|page=4|url=https://www.ntsb.gov/investigations/data/Documents/datafiles/PhaseofFlightDefinitions.pdf|access-date=10 May 2018}}</ref> 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 [[gliding|gliders]] attempt such climbs on a regular basis.

== Normal climb ==
[[File:Boeing_747-400_of_British_Airways_climbing_over_Bray_Lock,_20_May_2019.jpg|thumb|A [[Boeing 747-400]] of [[British Airways]] climbing out from [[Heathrow Airport|London Heathrow]], viewed from the [[River Thames]] at [[Bray Lock]].]]
In some jurisdictions and under some conditions, normal climbs are defined by regulations or procedures, and are used to develop [[airway (aviation)|airway]] systems, [[airspace]]s, and [[Instrument Flight Rules|instrument procedures]]. 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 20 meters per km (120 feet per nautical mile) might be assumed during the development of a navigational procedure or while defining airspace limits in airport terminal areas.

== See also ==
*[[Rate of climb]]
*[[Angle of climb]]

==References==
{{Reflist}}

{{Flight phases}}
{{Authority control}}

[[Category:Aircraft aerodynamics]]
[[Category:Flight phases]]