Continuous descent approach

Last updated
Schematic descent profile of a conventional approach (red) and a continuous descent approach (green). Continuous descent approach.svg
Schematic descent profile of a conventional approach (red) and a continuous descent approach (green).

Continuous descent approach (CDA), also known as optimized profile descent (OPD), is a method by which aircraft approach airports prior to landing. It is designed to reduce fuel consumption and noise compared to other conventional descents. Instead of approaching an airport in a stairstep fashion, throttling down, and requesting permission to descend to each new (lower) altitude, CDA allows for a smooth, constant-angle descent to landing.

A continuous descent approach starts from the top of descent, i.e., at cruise altitude, and allows the aircraft to fly its individual optimal vertical profile down to runway threshold. Some airports apply constraints to this individual optimal profile.

United Kingdom

The approach to London Heathrow Airport uses CDA, particularly at night, to minimize noise pollution. [1] It is also used at Gatwick Airport. [2]

Related Research Articles

Heathrow Airport Major international airport in London, England

Heathrow Airport, originally called London Airport until 1966 and now known as London Heathrow, is a major international airport in London, England. With Gatwick, City, Luton, Stansted and Southend, it is one of six international airports serving London. The airport facility is owned and operated by Heathrow Airport Holdings. In 2020, it was the third busiest airport in the world by international passenger traffic, the twenty-second busiest airport in the world by total passenger traffic, and the third busiest airport in Europe by passenger traffic.

Airport Facility with a runway for aircraft

An airport is an aerodrome with extended facilities, mostly for commercial air transport. Airports often have facilities to park and maintain aircraft, and a control tower. An airport consists of a landing area, which comprises an aerially accessible open space including at least one operationally active surface such as a runway for a plane to take off and to land or a helipad, and often includes adjacent utility buildings such as control towers, hangars and terminals. Larger airports may have airport aprons, taxiway bridges, air traffic control centres, passenger facilities such as restaurants and lounges, and emergency services. In some countries, the US in particular, airports also typically have one or more fixed-base operators, serving general aviation.

Air traffic control Public service provided for the purpose of maintaining the safe and orderly flow of air traffic

Air traffic control (ATC) is a service provided by ground-based air traffic controllers who direct aircraft on the ground and through a given section of controlled airspace, and can provide advisory services to aircraft in non-controlled airspace. The primary purpose of ATC worldwide is to prevent collisions, organize and expedite the flow of air traffic, and provide information and other support for pilots. In some countries, ATC plays a security or defensive role, or is operated by the military.

Virgin Atlantic, a trading name of Virgin Atlantic Airways Limited and Virgin Atlantic International Limited, is a British airline with its head office in Crawley, England. The airline was established in 1984 as British Atlantic Airways, and was originally planned by its co-founders Randolph Fields and Alan Hellary to fly between London and the Falkland Islands. Soon after changing the name to Virgin Atlantic Airways, Fields sold his shares in the company after disagreements with Richard Branson over the management of the company. The maiden flight from Gatwick Airport to Newark International Airport took place on 22 June 1984.

Gatwick Airport Secondary airport serving London, England, United Kingdom

Gatwick Airport, also known as London Gatwick, is a major international airport near Crawley, West Sussex, England, 29.5 miles (47.5 km) south of Central London. It is the second-busiest airport by total passenger traffic in the UK, after Heathrow Airport. Gatwick is the tenth-busiest airport in Europe. It covers a total area of 674 hectares.

Landing Transition from being in flight to being on a surface

Landing is the last part of a flight, where a flying animal, aircraft, or spacecraft returns to the ground. When the flying object returns to water, the process is called alighting, although it is commonly called "landing", "touchdown" or "splashdown" as well. A normal aircraft flight would include several parts of flight including taxi, takeoff, climb, cruise, descent and landing.

Instrument landing system Ground-based visual aid for landing

In aviation, the instrument landing system (ILS) is a radio navigation system that provides short-range guidance to aircraft to allow them to approach a runway at night or in bad weather. In its original form, it allows an aircraft to approach until it is 200 feet (61 m) over the ground, within a 12 mile (800 m) of the runway. At that point the runway should be visible to the pilot; if it is not, they perform a missed approach. Bringing the aircraft this close to the runway dramatically improves the weather conditions in which a safe landing can be made. Later versions of the system, or "categories", have further reduced the minimum altitudes.

Aircraft noise pollution

Aircraft noise pollution refers to noise produced by aircraft in flight that has been associated with several negative stress-mediated health effects, from sleep disorders to cardiovascular ones. Governments have enacted extensive controls that apply to aircraft designers, manufacturers, and operators, resulting in improved procedures and cuts in pollution.

Aberdeen Airport International airport in Aberdeen, Scotland

Aberdeen International Airport is an international airport, located in the Dyce suburb of Aberdeen, Scotland, approximately 5 nautical miles northwest of Aberdeen city centre. A total of just under 3.1 million passengers used the airport in 2017, an increase of 4.6% compared with 2016.

Heathrow Airport Holdings is the United Kingdom-based operator of Heathrow Airport. The company also operated Gatwick Airport, Stansted Airport, Edinburgh Airport and several other UK airports, but was forced by the Competition Commission to sell them in order to break up a monopoly. It was formed by the privatisation of the British Airports Authority as BAA plc as part of Margaret Thatcher's moves to privatise government-owned assets, and was once a constituent of the FTSE 100 Index.

Spoiler (aeronautics) Device for reducing lift and increasing drag on aircraft wings

In aeronautics, a spoiler is a device which intentionally reduces the lift component of an airfoil in a controlled way. Most often, spoilers are plates on the top surface of a wing that can be extended upward into the airflow to spoil the streamline flow. By so doing, the spoiler creates a controlled stall over the portion of the wing behind it, greatly reducing the lift of that wing section. Spoilers differ from airbrakes in that airbrakes are designed to increase drag without affecting lift, while spoilers reduce lift as well as increasing drag.

Instrument approach Series of predetermined maneuvers

In aviation, an instrument approach or instrument approach procedure (IAP) is a series of predetermined maneuvers for the orderly transfer of an aircraft operating under instrument flight rules from the beginning of the initial approach to a landing or to a point from which a landing may be made visually. These approaches are approved in the European Union by EASA and the respective country authorities and in the United States by the FAA or the United States Department of Defense for the military. The ICAO defines an instrument approach as a series of predetermined maneuvers by reference to flight instruments with specific protection from obstacles from the initial approach fix, or where applicable, from the beginning of a defined arrival route to a point from which a landing can be completed and thereafter, if landing is not completed, to a position at which holding or enroute obstacle clearance criteria apply.

Flight management system

A flight management system (FMS) is a fundamental component of a modern airliner's avionics. An FMS is a specialized computer system that automates a wide variety of in-flight tasks, reducing the workload on the flight crew to the point that modern civilian aircraft no longer carry flight engineers or navigators. A primary function is in-flight management of the flight plan. Using various sensors to determine the aircraft's position, the FMS can guide the aircraft along the flight plan. From the cockpit, the FMS is normally controlled through a Control Display Unit (CDU) which incorporates a small screen and keyboard or touchscreen. The FMS sends the flight plan for display to the Electronic Flight Instrument System (EFIS), Navigation Display (ND), or Multifunction Display (MFD). The FMS can be summarised as being a dual system consisting of the Flight Management Computer (FMC), CDU and a cross talk bus.

Quota Count is a system used in the UK by London's Heathrow, Gatwick, and Stansted airports to limit the amount of noise generated by aircraft movements at night time (23:30–06:00).

British Airways Helicopters

British Airways Helicopters was a British helicopter airline from 1964 to 1986.

The expansion of Heathrow Airport is a series of proposals to add to the runways at London's busiest airport beyond its two long runways which are intensively used to serve four terminals and a large cargo operation. The plans are those presented by Heathrow Airport Holdings and an independent proposal by Heathrow Hub with the main object of increasing capacity.

Thames Estuary Airport Proposed airport near London

A potential Thames Estuary Airport has been proposed at various times since the 1940s. London's existing principal airports, Heathrow, Gatwick and Stansted, are each sub-optimally located in various ways, such as being too close to built-up areas or requiring aircraft to fly low over London. In the case of Heathrow, the growth of air traffic has meant that the airport is operating at 98% capacity. Several locations for a new airport have been proposed in the Thames Estuary, to the east of London. These include Maplin Sands off Foulness on the north side of the estuary; Cliffe and the Isle of Grain in Kent on the south side; and artificial islands located off the Isle of Sheppey such as the "Boris Island" proposal championed by Boris Johnson, the then Mayor of London. Economic considerations have so far ruled out a new coastal airport, while political considerations have ruled out a new inland airport, leaving planners with an as-yet-unresolved dilemma.

Airlink (helicopter shuttle service)

Airlink was the brand name of a helicopter shuttle service which ran between London's two main airports, Gatwick and Heathrow, between 1978 and 1986. Operated jointly by British Caledonian Airways and British Airways Helicopters using a Sikorsky S-61 owned by the British Airports Authority, the "curious and unique operation" connected the rapidly growing airports in the years before the M25 motorway existed. Although at one point the service was granted a licence to operate until 1994, the Secretary of State for Transport intervened and revoked the licence with effect from February 1986—by which time the continued existence of the link had become "a highly controversial issue" debated by Members of Parliament, airlines, airport operators, local authorities and many other interest groups. No similar service has operated between the airports since Airlink's cessation.

The expansion of Gatwick Airport has involved several proposals aimed at increasing airport capacity in south east England and relieving congestion at the main hub airport Heathrow.

Gatwick Airport was in Surrey until 1974, when it became part of West Sussex as a result of a county boundary change. The original, pre-World War II airport was built on the site of a manor in the parish of Charlwood. The land was first used as an aerodrome in the 1920s, and in 1933 commercial flights there were approved by the Air Ministry.

References

  1. BAA Heathrow (2004–2005). "Flight Evaluation Report 2004/05" (PDF). Archived from the original (PDF) on 2005-11-26. Retrieved 2 November 2007.Cite journal requires |journal= (help)
  2. BAA Gatwick. "Flight Evaluation Report 2006/07" (PDF). Archived from the original (PDF) on 27 February 2008. Retrieved 26 January 2008.Cite journal requires |journal= (help)