British Airways A350-100 descending into Heathrow April 2025

Inbound aircraft to London

Heathrow Airport Heathrow Airport , also colloquially known as London Heathrow Airport and named ''London Airport'' until 1966, is the primary and largest international airport serving London, the capital and most populous city of England and the United Kingdo ...

typically follow one of a number of Standard Terminal Arrival Routes (STARs). The STARs each terminate at one of four different RNAV waypoints (co-located with VOR navigational aids), and these also define four "stacks" where aircraft can be

held Held may refer to: Places * Held Glacier People Arts and media * Adolph Held (1885–1969), U.S. newspaper editor, banker, labor activist *Al Held (1928–2005), U.S. abstract expressionist painter. *Alexander Held (born 1958), German television ...

, if necessary, until they are cleared to begin their approach to land. Stacks are sections of airspace where inbound aircraft will normally use the pattern closest to their arrival route. They can be visualised as an invisible

helix A helix (; ) is a shape like a cylindrical coil spring or the thread of a machine screw. It is a type of smooth space curve with tangent lines at a constant angle to a fixed axis. Helices are important in biology, as the DNA molecule is for ...

in the sky. Each stack descends in intervals from down to . If these holds become full, aircraft are held at more distant points before being cleared onward to one of the four main holds.

The stacks

Bovingdon

The Bovingdon stack is for arrivals from the north west. It extends above the village of

Bovingdon Bovingdon is a village in Hertfordshire, England, south-west of Hemel Hempstead, and a civil parishes in England, civil parish within the local authority area of Dacorum. Situated close to the Buckinghamshire border, it forms the largest part ...

and the town of

Chesham Chesham ( , ) is a market town and civil parish in Buckinghamshire, England, United Kingdom, south-east of the county town of Aylesbury, about north-west of Charing Cross, central London, and part of the London metropolitan area, London ...

, and uses the RNAV waypoint BNN (co-located with the BNN VOR), which is situated on the former RAF Bovingdon airfield.

Biggin Hill

The Biggin Hill stack on the south east edge of Greater London is for arrivals from the south east. It uses the RNAV waypoint BIG (co-located with the BIG VOR), which is situated on

London Biggin Hill Airport London Biggin Hill Airport is a minor Commercial aviation, commercial airport serving Biggin Hill in the London Borough of Bromley, located south-southeast of Central London. It specialises in general aviation, handling a spectrum of traffic ...

Lambourne

The Lambourne stack in Essex is for arrivals from the north east. It uses the RNAV waypoint LAM (co-located with the LAM VOR), which is situated adjacent to

Stapleford Aerodrome Stapleford Aerodrome is an operational general aviation aerodrome in the Epping Forest district of Essex, England, near the village of Abridge. It is about south of North Weald Airfield and north of Romford. The airfield is just within the ...

Ockham

The Ockham stack in Surrey is for arrivals from the south west. It uses the RNAV waypoint OCK (co-located with the OCK VOR), which is situated on the former Wisley Airfield. During typical easterly operations, the proximity of arrival traffic via OCK requires departures from Heathrow's runway 09R towards the Compton VOR (CPT) to follow a non-standard departure procedure.

Developments

The arrival procedures are being revised since 2014 to reduce stacking by introducing variable speed limits and alternative holding procedures.

Incidents

At 6 am on 1 December 2003, a major disaster in the stack was narrowly avoided when two planes, carrying a total of 500 passengers, flew within of vertical clearance. An

air traffic controller An Air traffic controller (ATC) is a person responsible for the coordination of traffic in their assigned airspace. Typically stationed in area control centers or control towers, they monitor the position, speed, and altitude of aircraft and c ...

was blamed by a later inquiry for misdirecting traffic when he ordered a

United Airlines United Airlines, Inc. is a Major airlines of the United States, major airline in the United States headquartered in Chicago, Chicago, Illinois that operates an extensive domestic and international route network across the United States and six ...

Boeing 777 The Boeing 777, commonly referred to as the Triple Seven, is an American long-range wide-body airliner developed and manufactured by Boeing Commercial Airplanes. The 777 is the world's largest twinjet and the most-built wide-body airliner. ...

into a level of the Bovingdon Hold already occupied by a similar

British Airways British Airways plc (BA) is the flag carrier of the United Kingdom. It is headquartered in London, England, near its main Airline hub, hub at Heathrow Airport. The airline is the second largest UK-based carrier, based on fleet size and pass ...

aircraft.

References

External links

*{{cite web, url=http://avsim.com/atco/dayinthelife.htm , title=ATCO: Day in the life (a real life transcript of air traffic control in the area) , accessdate=2004-11-10 , url-status=bot: unknown , archiveurl=https://web.archive.org/web/20080229134124/http://avsim.com/atco/dayinthelife.htm , archivedate=29 February 2008
London 24 - Layers of London air traffic
NATS, 2014 Air traffic control in the United Kingdom Aviation in London Aviation in England Heathrow Airport