Figure 1 – Aircraft Tracks Prior to Modification of Route 4 RNAV 1 SID

On April 7th 2017, the Civil Aviation Authority (CAA) released CAP1531, “CAA conclusions in respect of modification requirements relating to Route 4 RNAV 1 SIDs and correction requirements relating to Route 4 Conventional SIDs”.

Cyrrus Instrument Flight Procedure (IFP) designers were responsible for redesigning the Route 4 RNAV 1 SIDs (LAM 2X, BIG 2X, CLN 4X and ADMAG 2X) to more closely adhere to the Noise Preferential Route (NPR). Route 4 is a heavily used departure route at Gatwick, accounting for approximately 40% of westerly departures.

The report states:  “The CAA has decided the modified Route 4 RNAV 1 SIDs (SID chart attached at Annex A) 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 AIP as permanent.”

Figure 2 – Aircraft Tracks After Modification of Route 4 RNAV 1 SID