CAA confirm Route 4 changes to be permanent – local group calls it the “Route to Misery”

Early in April the CAA approved the current P-RNAV design of Gatwick’s Route 4 (the take off route towards the west, that turns north and heads east). This was altered in 2016 in response to the complaints about the way it has recently been altered. Now, dismissing the outpouring of complaints to the current route “as expected”, the CAA says the route will continue.  The CAA has concluded that modified Route 4 “has delivered the aim of the airspace change to an acceptable standard and this change will now be made permanent.”  They recognise that this has an impact on communities and has asked Gatwick to “investigate the potential of meaningful respite” by “alternating or switching a proportion of Route 4 departures onto another route.” Local group, Plane Justice, deeply opposed to the current Route 4, comments that the CAA appears indifferent to the misery of the people who wrote in complaining about the route. They are angry that the complaints are considered just “AS EXPECTED” rather than real expressions of genuine concern and annoyance. The group has a Route 4 Legacy Pledge, which calls on the CAA to revisit its decision and return Route 4 to the geographical position and dispersion pattern it occupied before 2013 (the ‘legacy Route’). They are asking people to sign up to this.



18.4.2017 (Plane Justice press release)

In a decision that raises many more questions than it answers, the CAA has approved its second redesign of Gatwick departure Route 4 in three years, following its first attempt to introduce P-RNAV on this Route in 2013.

And in so doing, the CAA appeared indifferent to the misery of the people who wrote in complaining about the Route, by saying this outpouring was “AS EXPECTED”.

But it wasn’t so dismissive of the similar number of people who signed a petition complaining about the first redesign of Route 4, that became operational at the end of 2013.

The CAA’s conclusions seem a case of “If at first you don’t succeed, then repeat and compound your errors”.

A Commentary on the CAA’s decision can be found on the welcome page of our web site (

Residents visiting the website are also invited to sign up to the Route 4 Legacy Pledge, which calls on the CAA to revisit its decision and return Route 4 to the geographical position and dispersion pattern it occupied before 2013 (the ‘legacy Route’).

The decision raises many questions that will be posed in the coming weeks, and here are two:

  1. The ROUTE TO MISERY has been designed by first making a ‘correction’ – which the CAA had not required to be made for decades before now.

This ‘correction’ has the highly significant effect of moving the flight path roughly a kilometre further to the south, to a geographical position it has not occupied for decades, if at all (as residents who’ve lived here for 30 or 40 years will attest).  It’s also a major contributor to the over-tight turn of the current Route.

So a question for the CAA is:   Why attempt to design a departure Route blighting many thousands of residents for the first time, which is based on a flight path that in reality has not existed for decades?  

And why was making this correction not considered necessary, when the CAA attempted its first P-RNAV design for Route 4 in 2013? 

  1. The CAA has passed the buck to Gatwick, to conduct a ‘jam tomorrow’ review, to see if anything might be done to reduce the damage to residents of the current Route 4. This includes the suggestion of introducing a second Route 4 swathe to the north of the current one. 

This second swathe, if it came to fruition, would in all probability be located approximately in the position of the legacy Route (i.e. the geographical position of Route 4 prior to 2013, which kept the peace for decades in all communities with negligible complaints.) 

So the question is:  If the CAA can contemplate the addition of such a swathe, then why not simply return Route 4 to its legacy position in the first place?


To read the CAA’s full report relating to Gatwick Route 4 go to CAA conclusion to Route 4.

Notes to editors

  • Route 4 is the departure route from Gatwick which takes around 38% of all westerly departing aircraft. The Route was altered in May 2016 and now overflies new clusters of population in Newdigate, Capel, Leigh, Norwood Hill, Sidlow, Salfords and Outwood, with consequential vectoring overflights over Horley.  Despite an improvement over Horley following a ‘re-education’ programme for Air Traffic Control, the problem has worsened again in recent weeks, and the CAA’s decision only collates Horley data up to 23 February 2016.  This is a problem caused by the Route, not ATC.
  • Residents supporting Plane Justice are pressing for Route 4 to be returned (whether using P-RNAV or conventional navigation) to the geographical position and dispersal pattern it occupied for decades up to 2012 (the so-called ‘legacy route’), which kept the peace for decades in all communities north of Gatwick, with negligible complaints about noise. The legacy route is shown in the left-hand map below which shows a day’s-worth of aircraft flying the route.  The red-to-amber colour gradation reflects numbers of aircraft.
  • The swathe of the legacy route is compliant with the relevant ‘noise preferential route’ (NPR) legislation, which states that aircraft are deemed to comply with the NPR if they fly within 1.5 kilometres either side of the NPR centre line.
  • There is clear evidence that the new Route 4 (see right-hand map below), when flown in ‘real world’ conditions, is not compliant with the criteria originally set for it by the CAA and is based on a fundamentally flawed design.
  • Aircraft ‘balloon out’ in the over-tight turn as they struggle to fly it even in modest winds, and the prolonged use of flaps and slats required is spraying higher levels of noise over a wider areas of population. The route then compounds the misery by turning further south (by about a kilometre) than the legacy route did, thereby overflying many thousands more residents for the first time.  In doing so, the Route purports to be following a conventional (i.e. pre-P-RNAV) navigation Route that has not been flown for decades, if ever.

For further information, please contact Plane Justice:   07564 649069


See also:

CAA announces decision on Gatwick Airport’s Route 4 departure review

2017-04-07  (CAA website)

The Civil Aviation Authority (CAA) has today published the conclusions of its review of the Route 4 departure from Gatwick Airport.

In 2013 Gatwick Airport sought the CAA’s approval to implement changes to all nine of its departure routes. These changes were approved in August 2013, following consultation carried out by the airport.

This move represents a change from the old ground-based navigation to the improved navigational capabilities associated with satellite-based systems.

Whenever airspace changes are implemented, the CAA conducts a post implementation review to assess whether the anticipated impacts and benefits have met the desired expectations.

In December 2015 we announced the conclusion of our post implementation review, which found that Route 4 had not delivered the aim of the airspace change and needed to be modified to an acceptable standard. Route 4 departs from the westerly runway and then turns right to head east to route north of the airport.

Since then Gatwick Airport has modified Route 4. The CAA has now reviewed this route, which has included a comprehensive study of flight paths flown and an assessment of the significant amount of feedback received from the general public.

In conclusion, the CAA has decided that the modified Route 4 has delivered the aim of the airspace change to an acceptable standard and this change will now be made permanent.

The CAA recognises airspace changes can have an impact on communities and in making this decision, has asked Gatwick Airport to give a number of undertakings including:

  • To investigate the potential of meaningful respite, the airport will consider options for additional Route 4 departure designs, from the points where the route heads east.
  • To consider the potential for obtaining respite by alternating or switching a proportion of Route 4 departures onto another route.

Full list of undertakings can be found on page 10 of the report.

Gatwick Airport has been informed of our conclusions and will provide updates on the above undertakings on their website.

Stuart Lindsey, Airspace Regulation Manager at the CAA, said: “We have been reviewing data on Route 4 and considering in detail the feedback received from local communities to assess whether this route is now performing as required by us. We are satisfied the modified Route 4 is achieving this performance and it will therefore remain in place.

“We absolutely understand that airspace changes can impact communities and that aircraft noise can disturb many people.

“As we have done throughout this entire review, we will continue to consider the environmental impact of all our airspace decisions and have called on the aviation industry and other decision-makers to be much more ambitious in confronting aviation’s environmental challenges.”



The Gatwick blog, by Andy Sinclair, states:



Following the Post Implementation Review (PIR) of the runway 26 Route 4 RNAV 1 Standard Instrument Departures (SID) the CAA has concluded that the modified Route 4 SIDs achieve a satisfactory replication of the nominal track of the corrected conventional SID. The CAA has therefore decided to confirm the RNAV 1 SID designs currently published in the UK Aeronautical Information Publication (AIP) as permanent.

In its decision letter (CAP 1531) the CAA provided a series of suggested undertakings that we will study and draw into our work with the Gatwick Noise Management Board. The conclusion of the CAA deliberations and supporting data are published in full on the    [sic]

The CAA’s airspace change process in respect of Route 4 has now concluded.


The amendment to our easterly Standard Instrument Departures contained within the Noise Preferential Route known as ‘Route 5’ came into effect on 30 March.

We have established a dedicated website where a briefing document detailing the requirements behind the amendment can be viewed as well as the mechanism for leaving feedback:

Gatwick Airport will collate operational performance data and feedback statistics over a six month period and, as with Route 4, will provide this to the CAA for their consideration.