The CAA’s post implementation review of P-RNAV

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In line with CAA requirements, aircraft departing from Gatwick now fly using a method known as ‘Precision Area Navigation’ (P-RNAV). The system means departing aircraft follow more precise flight paths and has been introduced so that the CAA can eventually switch off ground-based navigation systems across the UK. 

Before any of this could happen, Gatwick had to design and introduce new flight paths that sit within the airport’s nine noise preferential routes (NPRs) or corridors that departing aircraft fly within. Aircraft started flying these modified flight paths in late 2013 and early 2014 and these routes have just been reviewed (post implementation review) by the CAA to see if they are compliant with regulations. 

Below is the 16th update in our series of blogs updating on progress following the CAA’s review.  

Update by Charles Kirwan-Taylor, Corporate Affairs & Sustainability Director

11 November 2016

Charles Kirwan-TaylorThe six months monitoring period of the amendment to Route 4 ends at 23:59 on 26 November 2016. As I have previously outlined, the Civil Aviation Authority (CAA) has been receiving monthly data packages from Gatwick Airport regarding route performance and feedback received, this activity however will cease with the end of the monitoring period at which time we will forward our final data package to the CAA and publish a data summary to this blog.

We will continue to monitor Route 4 performance in common with all other departure routes from Gatwick Airport and report accordingly in our Flight Performance Team reports to the Noise and Track Monitoring Advisory Group and the Gatwick Airport Consultative Committee; details of which are available online.

The CAA has undertaken to evaluate the data and decide whether the amendment has been a success or otherwise approximately three to four months after the end of the monitoring period.

After the cessation of the monitoring period:

  • The current amendment to Route 4 will remain in place at least until we hear from the CAA. This is because the route flown over the previous six months is not a trial but an amendment as required in the CAA Post Implementation Review. Should the CAA deem this amendment to be unsuccessful, it would be at that stage when we would consider other options available.
  • Should the airport be required to return to a conventional navigation procedure in the event the CAA deems the amendment to be unsuccessful, this would not be a permanent solution but would only be in place until alternative solutions are developed. This is because Performance Based Navigation (PBN) Standard Instrument Departure routes are UK CAA policy under international implementation policies and are expected to be mandated in terminal airspace from 2017.
  • The Route 4 dedicated email address will close at 23:59 on 26 November 2016. After this time, the method for registering noise complaints will be via our dedicated noise website

Route 4 Statistics

Total number of Route 4 specific complaints up to 11 November 2016: 15,689.

Track keeping broken down by the individual Route 4 Standard Instrument Departure (SID) Routes is provided in the table below: 

Please continue to send your feedback to Please note this email address is a no-reply email address and is used for data collection only. 

Previous blogs

31 October 2016
12 September 2016

4 August 2016
8 July 2016 
22 June 2016  
13 June 2016 
1 June 2016 
26 May 2016 
24 March 2016 
24 February 2016 
18 February 2016 
8 February 2016 
31 January 2016 
21 January 2016 
23 December 2016