heathrow airport

[glenis]

just driven home past the airport and must have counted 10 to 15 planes all stacked up in a holding patten waiting to land, i just wondered how many planes would be stacked up when the airport is at it's busiest? and as a matter of interest ,when is the busiest period??

[NORMANTHEDOG]

could be any number, up to 20 with planes leaving the stack to land and others joining it to wait,espeacilly in the mornings,they sometimes have 2 holding areas,one over surrey side and one over herts,amazing how it all fits together

[Trottie]

And more! There are 4 Heathrow Stacka, Bovingdon in Herts, Lambourne in Essex, Ockham in Surrey and Biggin Hill in Kent. They have a lowest level of about 7000 feet and an upper of about 15,000 feet (so about 9 aircraft per stack). In addition, there are stacks further out, eg Sabre over Southend. Because of the night movement restrictions, you find that the stacks get really full at about 5:30 am onwards - especially if it is foggy - and Air Traffic will issue Expected Approach Times to aircraft joining of over an hour away. As an educated guess, I reckon you could get up to 30 to 40 aircraft holding at any one time (more in exceptional circumstances!).
Normally Heathrow alternates its runways, using only one for take - offs and the other for landings, during the day (split morning and afternoon) - in the early morning they use both for landing after 6:00 am to get everyone down as quickly as possible.