Swanwick Airspace Optimisation Work Package 1 November 2016: v1.6
Contents Background Design Principles & Benefits Impact Assessment: Proposed STARs Change to Hold Definition Timeline/Engagement Slide 45
Background The Swanwick Airspace Optimisation Project is developing a series of route changes at higher levels over southern and central England. These will be delivered in a series of work packages which reduce complexity/increase efficiency for parts of the air traffic system. This presentation relates to Work Package 1: new RNAV1 Standard Arrivals Routes (STARS) for Gatwick & Heathrow Airports from the South & South West. Slide 46
Design Principles Produce a separated route structure using RNAV, deconflicting Heathrow and Gatwick arrival routes No changes to routes or tracks below 7000ft (no CAA requirement for local consultation) Improve flight profiles Benefits Reduce complexity and controller workload Enhance safety Improve fuel/co2 efficiency Slide 47
Today s Heathrow and Gatwick Arrival Routes Heathrow STARs Gatwick STARs Segments shared by both sets of STARs OCKHAM HOLD GATWICK HOLD (WILLO) Area of complexity Heathrow and Gatwick flows on same routes Flows from south and west converging Slide 48
Proposed routes Proposed Heathrow Routes Proposed Gatwick Routes Flows separated on an RNAV route structure over Isle of Wight and to the south Complexity of route system significantly reduced. Reduuced complexity: Separted flows form south Convergence point simplifed Slide 49
What will change? HAZEL This slide summaries the areas where overlifghts will change. The explanation is provided on subsequent slides Slide 50
Proposed Heathrow STARs compared to existing STARs Existing STARs Proposed STARs New route alignment over the South Coast HAZEL No new route alignment north of HAZEL (in the vicinity of Petersfield) Slide 51
Existing tracks - vectoring 5 Days of arrivals from Summer 2016 Existing STARs Proposed STARs Aircraft currently vectored in swathes from before the start of the STARs Flights are vectored towards Ockham hold or towards downwind approach path (shown by the arrows) Slide 52
Proposed STARs compared to existing tracks Proposed STARs Aircraft would be kept on the Heathrow STARs where they interact with the Gatwick STARs. This is over the channel and the south coast at higher levels. Concentration would increase in these areas. However, once clear, Heathrow Arrivals would still be vectored in a broad swathe towards Ockham or the downwind approach path as they are today (shown by the arrows). CONCLUSION: There would be no changes to tracks or concentration on, or abeam, the STAR north of HAZEL (min alt 14,000ft) Slide 53
Ockham Hold The Ockham hold is currently defined as a conventional hold. The CAA require that Holds on RNAV STARs are defined as RNAV holds. The proposal includes a converting the conventional hold to RNAV. This would not have a noticeable effect on tracks (as described in following slides). Slide 54
Ockham hold today The picture shows the race tracks for the Ockham hold at 14,000ft and 7,000ft. The race tracks vary because aircraft speed varies with height. Lower aircraft fly slower so the smaller racetrack relates to 7,000ft. Tracks in the vicinity of the Ockham hold are spread across a wide area. This is because: 1. Some aircraft are at different heights (therefore following different racetrack paths) 2. Some aircraft are being vectored over the area and not holding 3. Some aircraft are entering or exiting the hold which means flying wide loops either inside or beyond the racetrack areas 4. Variation in MET conditions 5. While all aircraft are currently flying RNAV overlays there may be small differences in the way these are coded into the FMS. Slide 55
Proposed RNAV Ockham hold The proposed hold is time based, rather than distance based as per the 2015 trial. The current conventional hold is time based also, therefore the proposal would not change the location the racetrack(s). Likewise it would not change the pattern of overflights, the entry/exit patterns, the variation in racetrack due to height/speed, or variation due to MET conditions. The only potential difference would be the result of the aircraft sharing a common RNAV coding within their FMS systems (whereas today there is scope for small differences in interpretation). Data from Gatwick TIMBA hold does not show any discernable difference in holding tracks (see following slide). Slide 56
TIMBA hold This shows a comparison of August 2015 and July 2016, before and after conversion to RNAV There is no noticeable shift in the northern part of the hold (this change also included realignment of the connecting STAR from the North East hence differences in the southern portion) There has been no adverse local reaction to the conversion of the hold Slide 57
Proposed RNAV Ockham hold CONCLUSION: The conversion to RNAV could theoretically cause a minimal shift to some tracks, but not enough to be noticeable given other variables. Slide 58
Next Steps NATS is aiming to implement the changes in April 2017 The ACP must be submitted by the end of November 2016 to achieve this It is a NATS sponsored change we would expect HAL to forward any queries/complaints to us We will review performance on an ongoing basis and publish a formal report as part of the post implementation review after 1 year Timeline and proposed engagement: Nov 23rd: Brief to CNF End of Nov: Brief to MPs beneath the holds End of Nov: Submit ACP CAA to publish on their site Jan 2017: Brief to HACC Feb 2017: CAA approval April 2017: Implementation April 2018: Post Implementation Review Slide 59