NATS says cross-border trial slowing planes up to 350 miles from landing, cuts Heathrow stacking times
NATS says their trial to cut the amount of time aircraft spend circling in holding stacks at Heathrow has started to reap rewards. As part of the UK-Ireland Functional Airspace Block (FAB) and in collaboration with FAB Eurocontrol (FABEC) and Heathrow Airport, the trial aims to cut average holding times by a quarter from the current 8-minute time,to 6 minutes. Since April 2014, NATS has recorded a reduction of up to one minute in holding times for those flights influenced by the trial, saving airlines some fuel and – they claim – aroud 5,000 tons of CO2 for their airline customers, as well as reducing noise for communities underneath the stacks. The trial has seen controllers in the UK, France, Ireland and the Netherlands working in partnership to slow aircraft down up to 350 miles away from London – in any direction – in order to minimize holding times on arrival. 350 miles is around the French/German border, the French/Spanish border or the north of Denmark. The aim is to make more improvements to getting planes to arrive at Heathrow on a direct route. Aircraft burn less fuel generally if flying a bit less fast.
Cross-border trial cuts Heathrow holding times
A trial to cut the amount of time aircraft spend circling in ‘holding stacks’ at Heathrow Airport has started to reap rewards.
Led by air traffic services provider NATS, as part of the UK-Ireland FAB and in collaboration with FABEC and Heathrow Airport, the trial has the overall aim of cutting average holding times by a quarter from the current time of eight minutes.
Since April 2014, NATS has recorded a reduction of up to a minute in holding times for those flights influenced by the trial, saving airlines around £1 million (€1.25m) in fuel and 5,000 tonnes of CO2, as well as reducing noise for communities underneath the stacks.
The trial has seen controllers in the UK, France, Ireland and the Netherlands working in partnership to slow aircraft down up to 350 miles away from London in order to minimise holding times on arrival. It is the first step of a broader strategy to reduce the amount of time aircraft spend holding at Heathrow.
Absorbing delay in the en-route phase, when aircraft are higher and more efficient, saves fuel and CO2 while minimising noise for the communities living beneath the stacks.
Heathrow is scheduled to 98% capacity and relies on having the continuous flow of traffic that the stacks provide, but NATS’ aim is always to minimise the amount of time aircraft have to spend in them. Traditionally, it can only influence an aircraft’s approach to Heathrow once it enters UK airspace, which is sometimes only 80 miles from the airport. This therefore limits the chance to manage the inbound flow of traffic.
Martin Rolfe, NATS Managing Director, Operations, said: “Taking 60 seconds out of holding for trial influenced aircraft may not seem a lot, but it is a significant achievement and equates to serious savings for our airline customers while proving that this kind of cross border cooperation can reap real benefits. The next steps involve us taking what we’ve learnt so far and improving and refining our procedures for even greater results.”
Derek Provan, Airside Director at Heathrow Airport, said: “This trial is a definitive step in the right direction towards quieter and more sustainable airline operations. We welcome the efforts NATS has made, and for working with us to make Heathrow a better neighbour to local residents.”
In September 2014 the trial entered its third phase, with the minimum stack delay threshold reduced from nine minutes to seven and the maximum speed reduction raised to 0.04 Mach from 0.03. Moreover, the Brest Air Traffic Control Centre (ACC) also joined the trial to take into account more inbound traffic.
Maurice Georges, Chief Executive Officer of DSNA, the French Air Navigation Service Provider, added: added: “With Brest ACC joining the trial, we have symmetry in the application of XMAN [means Cross Border Arrival Management] procedures.
“At the same time, under the umbrella of the SESAR programme, Reims UAC has refined the concept and introduced a new prototype for gathering London arrivals data and an improved radar trajectory prediction model. The ‘working together’ spirit is bringing real benefits to the community!”
This trial demonstrates the UK-Ireland FAB’s, FABEC’s and Heathrow’s commitment to deploying innovative SESAR concepts as part of its implementation plan, and also the practical achievement of inter-FAB collaboration.
The XMAN project was highly commended at the Institution of Engineering and Technology’s innovation awards in the Intelligent Systems category.
Cross Border Arrival Management (XMAN) Trial
June 2014 (NATS)
A new operational procedure to cut the amount of time aircraft circle in ‘holding stacks’ at London Heathrow Airport began on 1st April.
Traditionally NATS has only been able to influence an arriving aircraft’s approach to Heathrow once it enters UK airspace – sometimes only 80 miles from the airport. This limits the opportunity to manage the flow of traffic and can result in additional time spent in the holding stacks.
As part of the Cross Border Arrival Management (XMAN) trial, if delays in the Heathrow holding stacks begin to build, air traffic controllers in the Netherlands, France, Scotland and Ireland will be asked to slow down aircraft up to 350 miles away from London to help minimise delays on arrival.
The trial is being led by NATS in close cooperation with DSNA, Maastricht Upper Area Control Centre, the IAA and Prestwick Control Centre, with the aim of cutting average stack holding times by at least a quarter from the current time of just under 8 minutes
The trial, which is a partnership between members of FABEC and the UK/Ireland FAB, will run until the end of 2014.
NATS hopes to continue improving fuel efficiency improvements, but its 3Di scheme does not take noise into account
According to UK air traffic services provider NATS, the environmental and operational efficiency of UK airspace improved during the first half of this year. However, it faces a challenge to meet a new tighter year-end target set by the CAA. In 2012, NATS was set an incentivised efficiency performance target (called 3Di -meaning 3 dimensional inefficiency) by the CAA. Its aim is to get the most direct and most fuel efficient routes, saving aircraft having to stack, and cutting fuel use and CO2 emissions. Each flight is given a score of its efficiency, with zero being best. Most flights typically score between 15 and 35. This year the CAA set NATS an overall target of 23. Their score was 23.7 in 2013 and a score of 23.9 in 2012. NATS says it it achieves its target scores over 3 years, planes will have saved around 600,000 tonnes of CO2 will have been saved. As well as CDA (continuous descent approach) landings, smoother take-offs, and flying at the optimum level. NATS is straightening flight paths. Their 3Di scores to not take account of the noise nuisance, and there are fears that some new flight path changes, helping NATS meet their target, are creating more noise from over-flying new areas.