ASSTAR Airborne Separation Applications Craig Foster Probably need a short bio… Masters in Mathematics from Imperial College, London Decided not to work in the City but to try his hand at making a fortune in the air traffic management industry. Started work on operations research concepts and projects including separation monitoring and risk to third parties. Moved on to manage the operational monitoring of TCAS in UK airspace. Then moved in to NATS R&D and worked on ADS-B monitoring and managed the CRISTAL UK project which was NATS first ADS-B operational trial. Culminating in the development of NATS strategic direction for ADS-B and multilateration technologies. In addition to all this, since June has also followed the career path for anyone who has ever worked on TCAS and moved on to lead NATS ASAS research portfolio. Your programme will say Mark Watson should be presenting this talk. As you can see I’m not Mark he sends his apologies but he is in the process of moving house so since he’s not here I can say that you are lucky to have the younger, fitter, taller, more hair, more handsome, possibly less controversial version Restricted to the ASSTAR template – so sorry to disappoint those who wanted to see NATS new stripy branding

Contents Describe ASSTAR Applications Concept Environment Commonalities Between Applications Use of Datalink An Operational (ANSP) Viewpoint Hopefully Short presentation with a simple brief to describe the ASSTAR applications. Since this is an ASAS conference I should be preaching to the choir although I’ll spend a bit of time on the oceanic environment as this is possibly new to some. In addition it is interesting to note some of the ASSTAR observations on the commonalities of the applications I’ll also present some thoughts on the use of datalink and an ANSP view. Again personal opinions – not speaking for NATS policy

Operational Concept Airborne Separation Applications Controller delegates separation responsibility and transfers separation tasks to the flight crew Flight crew ensure applicable airborne separation minima are met Responsibility limited to separation from a designated aircraft Separation provision still the controller’s responsibility Self-Separation Applications Require flight crews to separate their flight from all surrounding traffic In terms of the PO-ASAS categories we are considering 2 responsibility levels – the Airborne Separation (ASEP) applications Delegation of separation limited to single designated aircraft. Separation provision of that aircraft from all other aircraft still the controller’s responsibility. Self separation The extension whereby we require the aircraft to separate itself from all other aircraft.

Applications by Responsibility Separation Applications Crossing & Passing (ASEP-C&P) In Trail Follow (ASEP-ITF) In Trail Procedure (ASEP-ITP) Self-Separation Applications Free Flight Track (SSEP-FFT) New Application from Glasgow ASAS-TN Workshop In Trail Merge (ASEP-ITM) Radar Airspace Oceanic Airspace The applications which were identified at earlier user workshops and then explored were At the ASEP level Advanced crossing and passing ITF ITP And at the SSEP responsibility level FFT We have also just begun exploring an application which my colleague Bob McPike presented at the Glasgow ASAS-TN which we have called ITM We are considering these applications in two environments Radar airspace Oceanic airspace

ASEP-C&P Turning Point First the radar airspace application ASSEP C&P Description To allow a controlled and suitably ASAS equipped aircraft to modify its horizontal trajectory in order to achieve lateral separation by itself (airborne separation) from another converging controlled flight independently of vertical profile Expected benefits With no change in current ground separation minima, capacity and flight efficiency gains are expected by allowing aircraft to fly more closely to their original flight plan and possibly reducing the number of deviations from flight plan Presently, the actual distances for crossing aircraft exceed the applicable separation minima in radar airspace by a large margin. This is because the air traffic controller anticipates and manages his workload by issuing early spacing manoeuvre instructions The operational environment for this application is envisaged to be radar en-route airspace in Europe

ASEP-C&P - Offset 1st algorithm considered a single turning point – second considers the other method of flying an offset. Needless to say the methods considered were both pass in front and pass behind.

Oceanic Environment No VHF Radio or radar cover over most of the North Atlantic Region (NAT) Voice communications provided by High Frequency (HF) Radio HF subject to weather effects Audibility can be limited Sometimes impossible So ATC issues strategic clearances Issued prior to entering Oceanic FIR Extend from Oceanic Control Area (OCA) entry to landfall Long-term conflict prediction used to ensure no separation loss over whole route That was the radar airspace application. Before moving on to describe the oceanic applications it is beneficial to quickly describe the oceanic environment since it is quite specialised and may be unfamiliar to some. We can’t see aircraft, and sometimes we can’t talk to them, so ATC issues strategic clearances Cleared from entry to landfall using long-term conflict prediction. Organised Track Structure

Organised Track Structure Diurnal pattern of eastbound in the morning and westbound in the evening. Each day establish the organised track structure 5-6 parallel tracks Based on weather patterns and airline demand. NATS responsible up to 30W

Oceanic Separations 10 mins 15 mins 60 miles 1000 ft Separation standards governed by various uncertainties: Communication unreliability Navigational accuracy Accuracy of forward estimates (driven by weather forecasts) . . . so separation standards are very large 10 mins 60 miles 1000 ft 15 mins Separation standards are governed by various uncertainties, principally: Poor reliability of HF Some aircraft still have no GPS and lack of surveillance means GNEs can be difficult to detect Reliance on forward estimates for strategic clearances based on 12 to 24 hour forecasts For aircraft through a common point – 10 minutes longitudinal If not through a common point – 15 minutes as weather inaccuracies may not be the same for both aircraft Use ADS-C or HF position reporting to maintain situational awareness.

SAATS System which is used is SAATS Shanwick Automated Air Traffic System Developed in collaboration with NavCanada extension of the GAATS systems - important as effectively moving towards a commo platform for te Ocean – only responsible up to half way – common platform has obvious benefits Paperless flight strips, integrated Datalink communications and ADS-C reporting Went in to operational service 21st November 2006 on time and budget. SAATS replaced the NATS Oceanic FDPS1 System, which entered service in October 1987, was formally switched off for the last time on 22 February 2007.    FDPS1 was the CAA's second Oceanic system, in 1987 it replaced an earlier system hosted on Ferranti Apollo equipment.    The Ferranti Apollo, from 1961, was a landmark:  the world's first use of a digital computer for air traffic management. The oceanic operation is procedural which might make it seem a bit parochial but it has very advanced systems and embrases new technology

OAC Movements 2002 Illustrate show some reasonably recent movement figures to show the scale of the operation. Come a long way since Alcock and Brown performed the first non-stop flight across the Atlantic on 14th June 1919, with a flight time of 15hours 52 minutes. Now on to the ASAS applications being considered in ASSTAR Charles A. Lindbergh's 1927 achievement, winning the Orteig Prize, which was the first solo crossing, and also the first nonstop airplane crossing from the American mainland to the European mainland, Lindbergh was the 104th person to fly the Atlantic.

ASEP-ITP (In Trail Procedure) But standard longitudinal separation does not exist at level above Crew request an ITP Climb Aircraft at FL340 would like to climb ….. > 10 mins > 10 mins FL360 FL350 ATSA-ITP Criteria 5 mins Aircraft at FL340 would like to climb . . . . . . but climb is prevented due to insufficient longitudinal separation from the aircraft at FL350 . . . although required separation is available at FL360 If ITP criteria are met (340 aircraft ADSB in/out, 350 a/c ADSB out, min sep and max closing speed) crew can request an ITP climb ATC issue ITP clearance a/c climbs to FL360 where he has required long sep Manoeuvre complete Based upon Package 1 application ATSA-ITP Differences Active monitoring phase during flight level change Aircraft are responsible for separation Similarities Applicability conditions unchanged FL340

ASEP-ITF (In-Trail Follow) Second climb approved –Maintaining ITF Separation In-Trail Follow cancelled Exit Oceanic Airspace Climb Approved, Maintaining In-Trail Airborne Separation In-Trail Separation maintained over extended period Airborne Separation Established: In-Trail Follow 5 minutes : No standard longitudinal separation FL360 FL350 ITP is only suitable for 2000’ climbs – but suppose a 1000’ climb is required a/c at FL340 wants to climb to FL350 If ITF criteria are met (340 aircraft ADSB in/out, 350 a/c ADSB out, min sep and max closing speed) ATC can issue an ITF clearance ITF separation established – red aircraft now responsible for monitoring and maintaining designated separation from lead aircraft Aircraft climbs ITF maintained over required period Aircraft requests a second climb ITF maintained until established at FL360 ITF cancelled Based upon Package 1 application ASPA-S&M Differences Aircraft are co-altitude Aircraft are responsible for separation Extended duration (several hours) Spacing defined in minutes rather than seconds Similarities Procedural termination condition - exit from track Merge instructions can be used to initiate spacing at track entry Benefits Aircraft Operator ITP Increased level change opportunity & hence ability to fly at preferred level Reduced Fuel Burn Cost Environment ITF Substantially improved availability of preferred level (ITF) ANSP No significant controller workload impact (ITP) Reduction in controller workload (ITF) ITF 5 mins FL340

SSEP-FFT FFT is an OTS track reserved for ASAS-capable aircraft Aircraft on the track can change speed and level at their own discretion . . . but no lateral flexibility allowed Aircraft requires downstream clearance to re-enter managed airspace Anticipated Benefits enabling more aircraft at the flight levels of a track (due to lower longitudinal separation criteria) enabling more frequent flight level changes or even cruise climbs enabling more freedom in speed selections these factors contribute to better flight efficiency, improved track occupancy and improved safety controller workload reduction SSEP-FFT characteristics Separation responsibility relative to all aircraft on the Free Flight Track is transferred to the flight crew, for an extended period of time New entry/exit procedures will be required aircraft will receive a clearance to enter the Oceanic Free Flight Track aircraft will receive a clearance to return to managed airspace An Oceanic Free Flight Track has to be defined (in space, in time, legally) Benefits Aircraft Operator: Substantially Improved Flexibility to fly at preferred level and speed Airline cost saving (reduced fuel-burn) Environmental benefits (reduced fuel burn) Adverse impact on flexibility for non-equipped aircraft? ANSP: Substantially reduced controller workload for normal operation But adverse impact on ATC ability to manage non-normal conditions?

Tactical re-routes in the NAT The motivation for the ITM procedure. This idea was first described at the ASAS-TN in Glasgow Eastbound oceanic traffic is a major problem for European domestic centres Traffic is highly concentrated, with up to 700 flights arriving in a short period and at the same time as the first rotation of domestic services Results in a high number of complex interactions which is often managed by restricting domestic flights Proposals for reduced lateral and longitudinal separations in the NAT will lead to even higher traffic concentrations At the moment, OTS traffic presents over a wide front (300+ NM) If lateral separation is reduced to 30 miles, the same traffic volume could be concentrated into 150 NM, forcing domestic sectors to introduce flow restrictions to protect themselves An alternative would be to allow traffic to concentrate for most of the crossing, then to spread out (laterally and vertically) to spread the load across a wider number of sectors

ASEP-ITM (In Trail Merge) 15 minutes 4 minutes ITM New WP-8 to investigate Opportunities Procedures The problem with spreading traffic at present is the 15 minutes separation required for traffic not through a common point ITM, however, would allow traffic to switch tracks at much lower separations, typically 3-4 minutes ITP/ITF would also be used to create a vertical spread by moving (e.g.) traffic for London TMA to lower levels Subject of the new ASSTAR WP-8 which will describe the procedure, identify the conditions for use and so identify the scale of opportunities for this application. Initial OSED draft under review but still under construction.

Application Commonalities Equipment ADS-B IN CDTI functionality Require High ADS-B Out equipage Common phases of application ATC Institutional issues for delegation Transition issues - from today to tomorrow Interface with managed airspace Early adopters of ADS-B in get the benefits but require the aircraft population to have a high level of ADS-B Out equipage What should the requirements be – as strict as for RAD or NRA? Phases similar Identification, Clearance, Execution, Termination Same equip, same procedures for setting up, ATC commonalities implications of delegation to the pilot SSEP ATC still aware of what’s going on in case it all goes wrong and we’re managing the surrounding tracks. our dependence on them and how do we get assurance that they can carry out that procedure Transition issues same issues 3rd party ID,

Use of Datalink Assumed that this is post-Package 1 and that ADS-B IN (and data link) would be available. All ASSTAR applications designed to use both HF voice communications and datalink… … but we wouldn’t want to use HF Only consider these applications in a datalink environment Designed to use either HF or datalink However, messages are long, complicated and HF is not ideal for the task. Only consider these applications using a datalink Current equipage 40% CPDLC and ADS-C

Operational Perspective - NATS Potential environmental and cost benefits to our customers NATS needs to understand the implications of implementing Capacity effects of FFT Control of adjacent tracks Management of traffic at the domestic interface Regulatory issues Need for harmonised approach with adjacent ANSPs Exploring other complementary options Improved Vertical Profiling (IVP) Applications have potential Implications of airlines wanting to use these application on NATS ability to manage this operation effects of FFT if best route given to only a select few control of aircraft on adjacent tracks and integration issues management of traffic once it gets to the other side – flow must be controlled and managed appropriately regulatory issues may be significant hurdle – delegation (no different to all ASEP) must be a complete solution for the ocean which means working with adjacent ANSPs to ensure commonality of approach: ISAVIA NavCanada Personal view. These ASAS applications are still firmly within the R&D domain. Considering other options including IVP – ground-based solutions, benefits explored, sims underway Positive ITF/M/P all complementary to current plans for oceanic airspace development SEE D4.2

Thank you for listening craig.foster@nats.co.uk

Operational Perspective - DSNA DSNA intentions in ASSTAR: Opportunity to re-activate and extend visual separation clearance used in the past. New sharing of tasks between air and ground should have a positive impact on ATCO workload Capacity effects of C&P for the ATCO Flight efficiency of C&P