Heathrow Hub is an independent proposal to expand capacity at Heathrow Airport by extending both of the existing runways up to a total length of about 7,000 metres and dividing them into four so that they each provide two pair of full length, in-line runways, allowing simultaneous take-offs and landings.

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  1. How to ensure the planes landing and take-off in the same runways safety?

  2. How many flight can be handled by such design, and how efficiency it is compared to two runways using segregated parallel operations (one for landing and another for takeoff)?

  • $\begingroup$ I get what RedGrittyBrick is saying, but my response to him is "we should speculate on what these impacts are on flight ops". However, that leads us to a question closure as primarily opinion based. On the other hand, since this has never been done before, we have only speculation or (if someone can find it) access to Heathrow Hub's studies on safety/efficiency/capacity/etc. I like this question, but I'm not sure we can answer it within the SE guidelines. $\endgroup$
    – FreeMan
    Commented Aug 6, 2015 at 18:49
  • $\begingroup$ It's not really the same scenario, but there's some similarity to the setup for Oshkosh, where they famously mark multiple landing points on their runways using colored dots, to fit in as many aircraft operations as possible simultaneously. It's not at all the same thing as airline operations, of course. $\endgroup$
    – Pondlife
    Commented Aug 6, 2015 at 19:10
  • $\begingroup$ The Heathrow Hub project hasn't published their detailed safety analysis, although RedGrittyBrick's links do touch on the issue. I think the bigger question re: safety, though, is "how would you set up the missed approaches to avoid conflicting with the departures, especially if someone goes around waaaay late?" $\endgroup$ Commented Aug 6, 2015 at 22:19

1 Answer 1


How to ensure the planes landing and take-off in the same runways safety?

No one knows.

Note this isn't exactly what is being proposed

By dividing it in two with a generous central buffer zone, we create two in-line runways, allowing aircraft to simultaneously land on one and take off on the other.

So that isn't simultaneous landing and taking off on the same runway.

Currently only one LHR runway is used for take-offs at any time. The runway is switched to provide respite from noise to local residents in the take-off path.

Also the surrounding airspace isn't set up in a way that would allow separation for concurrent take-off from two runways. A major reorganisation would be needed of airspace in that region of the UK.

I believe that currently, simultaneous take-off require parallel runways a mile or more apart.

How many flight can be handled by such design

No one knows. Maybe a c 46% increase from 480,000 to 700,000 air transport movements a year. See reference below. Bear in mind that Heathrow is subject to a night-time curfew.

How efficient is it compared to parallel runways?

No one knows.

According to the airports commission in 2014:

The concept of an in-line runway is unconventional, has never been used elsewhare and is not envisaged in international, EU or national regulatory instruments, standards or recommendations for safe design or operation.

  • $\begingroup$ They do this sort of in-line runway operation every year at Oshkosh, minus the "buffer zone" (this year's NOTAM is available here). It can be done safely, but i's definitely "unconventional". $\endgroup$
    – voretaq7
    Commented Aug 10, 2015 at 21:04
  • $\begingroup$ And if the landing aircraft overruns the runway and crashes into the aircraft waiting to take off on the next runway in line? $\endgroup$
    – Vikki
    Commented Aug 10, 2019 at 2:55

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