Independant Parallel Approaches (IPA)

An interim measure

Heathrow wants to bring in 25,000 more flights a year between 2022 and when any new runway opens (expected to be 2026).

To do this, it is proposing that these extra flights use new dedicated flight paths.

These flight paths would only be in existence during those years.  If a third runway opens they would cease.  Only if Heathrow remains a two runway airport would they continue.

Why are they being brought in?

At present when planes land over London, they switch runways at 3pm to give people in West London a break from the noise.  However, Heathrow is allowed to land a small number of planes on the ‘wrong’ runway, i.e. out of alternation, if delays are building up.   Between 7pm and 11pm, this currently amounts to 15 a day. For the hour between 6am and 7am when Heathrow has always been allowed to use both runways for landings there are currently 16/18 flights an hour landing on the ‘departures’ runway. 

The problem Heathrow has right now is that two planes can’t land on parallel runways at the same time.  This means that, in order to allow a plane to land on the ‘wrong’ runway, the gap between planes landing on the other runway has to be extended, thus reducing capacity. IPA is an attempt to get round this.  

What is Heathrow proposing?

New direct flight paths will be introduced from the holding stacks to the airport for planes coming in on the ‘wrong’ runway.  At this stage we don’t know exactly where these flight paths will be.  

The new flight paths

What Heathrow has published are the broad areas where one or more of these new flight paths may be.  The areas are outlined here: 

At this stage the fact you are in an area only means you might have a flight path overhead.  The detailed flight paths will not be published and consulted on until 2020.

There will be at least one new flight path from each of the ‘holding stacks’ (the places where planes wait before being guided down to Heathrow).

There are four of these:

  • Bovingdon (near Amersham)
  • Lambourne (near Epping)
  • Ockham (near Leatherhead)
  • Biggin Hill (near Bromley)

For operational reasons there will be fewer flight paths from the Biggin Hill stack.

The nature of the flight paths

They will be dedicated flight paths, reserved for these additional planes.  They will be narrow and concentrated.

How many aircraft will use them?

Between the hour of 6am and 7am, there will be a maximum of 25 flights.  That is not per flight path but across all the flight paths.  Heathrow expects the typical figure may be a total of about 18 flights.

Between 7am and 11pm, Heathrow expects there will be no more than a total of 15 planes across all the flight paths with a maximum of 40.

What about heights?

The planes will be at the same height as existing aircraft. 

Will I get both departures and landings?

Heathrow is saying that they will try to ensure that areas which currently experience departures will not have one of these new flight paths.

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