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Oceanic ATM

CApACITy eNhANCemeNT fOR AUSTRALIA’S mAjOR AIRpORTS

writer: iAn ThompSon

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nitiatives to improve airspace and airport capacity at Australia’s major airports are fostering unprecedented cross-industry collaboration.

Four initiatives are underway at Perth, Brisbane, Melbourne and Sydney airports to optimise airport movement capacity and operations in surrounding airspace.

These initiatives comprise an airport-directed slot management system, the Airspace Capacity Enhancement (ACE) program, Metron Flow Control and daily performance reporting to achieve continuous improvement.

In the past, highly tactical methods of providing airport infrastructure and air traffic services dominated thinking. Airlines had discretion over when they preferred to operate, with airports and Airservices providing infrastructure and services to meet this demand as best they could. Aircraft delays in the air and on the ground were accepted as a natural consequence and managed by operational staff.

However, the sharp increase in aircraft movements arising from increased airline competition and large numbers of fly-in/fly-out (FIFO) movements has resulted in extreme pressure on airport infrastructure and the air traffic management (ATM) system at peak periods. Solutions that involve providing more airport infrastructure and new ATM systems are both extremely costly and involve long lead times to plan, procure and bring into service. When user demand exceeds the capacity of airport infrastructure and the ATM system, aircraft generally receive airborne or ground delays. These delays increase airline operating costs.

Over time it had been largely the responsibility of Airservices to manage movement capacity issues with airlines. Airports typically had a limited focus undertaking master planning, addressing aircraft ground congestion and managing the noise issues with local communities arising from increased air traffic. In the past 18 months new strategic initiatives have been introduced by airport companies and Airservices to better meet the demands of increased traffic levels. This has seen airports become an integral element in a national solution, implemented at a local level, to address these system capacity problems. Airports are beginning to appoint senior operations managers who have a background in ATM capacity planning.

Metron Flow Control was implemented for Sydney and Perth in March 2012 and became operational at Brisbane in December 2012. It is a pre-tactical method that seeks to balance traffic demand with the capacity of the ATM system.

Next-day aircraft schedules and weather forecasts are uploaded into the Metron system. This information is sourced from airport slot management schemes. Software algorithms process weather forecast information with predicted flight profiles and aircraft operating parameters to establish the arrival and departure rate for the day. Metron then integrates the proposed flight schedules with the predicted arrival and departure rate. The outcome sees departing aircraft assigned a departure time, while arriving aircraft are given a target arrival time. In the case of more than one aircraft seeking the same time, Metron randomly chooses the order and places other aircraft into slots as close as possible to

their requested time. Meanwhile, enhancements are being

undertaken with regular scheduled airlines and the meteorological service to introduce more accurate weather parameters into the calculation of the arrival and departure rate.

Metron is primarily an ATM tool managed centrally from Airservices National Operations Centre (NOC) in Canberra. It performs well when used to balance capacity and demand in the ATM environment, but it is not designed to manage the strategic process of assigning airport slots to airline flight schedules. Nor is it suited to applying local rules at different airports. When this has occurred, some user resistance to Metron implementation and non-compliance to procedures has resulted.

A cornerstone initiative for Perth and Brisbane airports has been the introduction of a slot management scheme. It is a strategic tool initiated when an airline applies to introduce

a scheduled service at an airport. These slot management schemes are the first gateway in regulating aircraft operations at an airport and for the ATM system.

Both Perth and Brisbane have slot management schemes based on IATA Worldwide Slot Guidelines with local rules defined for how slots are assigned. While both airports set the rules for how the schemes will operate and procedures to monitor performance, day-to-day management is undertaken by Airport Coordination Australia.

BrisbaneFor Brisbane Airport, the slot management program is termed the Runway Demand Management Scheme (RDMS). The RDMS was first implemented in October 2012 in response to increasing demand and a request from Airservices that the airport implement a slot management system before the introduction of Metron Flow Control. Lessons learned from the Metron implementation at Perth identified the need for an airport solution to regulate traffic demand.

In the first months of operation Brisbane had some teething troubles in accurately defining the appropriate aircraft movement metrics that could be achieved. Unlike Perth, Brisbane did not have data about actual arrival and departure rates achievable with the operation of Metron procedures.

Mark Willey, head of airport development at Brisbane Airport Corporation (BAC) explained: “At the outset of RDMS, movement metrics were defined that were a stretch target based on the demand that was presenting at peak periods. A capacity study undertaken by UK ATM provider NATS suggested a marginal increase in the arrival rates could be achieved.

“The RDMS arrival and departure rates for runway 01/19 had been based on an assumption of good weather conditions, which provides for 27 arrivals per hour and a maximum of 50 total aircraft movements. This assumption of a high percentage of good weather operations was overly optimistic for RDMS Season 1, with extended periods of poor conditions being experienced exacerbated by the closure of the crossing runway for early works associated with the new parallel runway,” Willey said.

“In comparison, the arrival rate metric for Metron, which became operational at Brisbane two months

Lessons learned from the metron implementation at perth identified the need for an airport solution to regulate traffic demand.

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In the slot

after RDMS, is about 23 per hour, which is four less than RDMS. This imbalance was addressed in our first review of the system and we are now de-peaking the arrival rate in high demand periods to an arrival rate below 27. With operations now able to take place on the crossing runway, the Metron rate in daylight hours is up to 28 arrivals per hour.”

Two other issues have presented some complexity. Non-scheduled services such as the Royal Flying Doctor Service (RFDS) or business jets are not incorporated into the RDMS seasonal schedule and often seek to operate with less than 24 hours notice. RFDS operations can account for up to 30 movements on some days. These operations need to secure an RDMS slot and a space in Metron from Airservices’ NOC and are subject to gaps being available in the aircraft movement schedule.

Airlines wishing to secure FIFO contracts need to confirm their ability to operate at specific times as part of the tender and contract negotiation process with resources companies. However, these times are not able to be confirmed without a formal schedule request. This presents difficulty for FIFO airlines entering into contracts with clients, which often stipulate performance compliance to assigned departure and arrival times.

A review of the efficacy of the RDMS is planned to occur every six months aligned with international scheduling seasons, with the first two reviews having taken place in February and April 2013. Taking into consideration the need to provide gaps in the schedule for non-scheduled services, some contraction in the hourly movement rate is desirable.

BAC is mindful of the lead-time to

reduce movement rate metrics and the need to maintain ongoing slot times for scheduled services. Adoption of a more conservative rate requires a number of months’ notice along with negotiation and consultation before reduced slot availability can realistically be incorporated into airlines’ schedule planning. It is expected an increase in the hourly movement rate in line with the optimal capacity will be achieved through the implementation of ACE airspace enhancement initiatives.

perthThe Slot Co-ordination System (SCS) at Perth Airport has been operational since March 31 this year, one year after the implementation of Metron. From having a significant body of performance data, it has been a straightforward process to align the movement rates of both systems.

Peter Cock, executive general manager, operations & customer experience at Perth Airport said: “We started discussions early with Airservices to determine the appropriate movement metric well in advance of the SCS implementation date. The intention was to agree a figure that could be incorporated into both SCS and Metron. We intentionally defined a challenging movement rate

for the system to achieve.”One of the challenges Perth Airport

had to address was the development of local rules for SCS that addressed the operational needs of FIFO airlines and the resources sector. Cock describes the allocation process for these users.

“In setting local rules we adopted principles that included issuing SCS slots up to its maximum capacity, not holding spare capacity and providing grandfather rights to a slot occupied by a FIFO airline in the same manner as a RPT airline. Although a slot is assigned to a FIFO airline it is also linked to a specific route. This enables a slot to be assigned to a different airline should a contract for FIFO services change,” Cock said.

“We also need to guard against an event where one FIFO airline assumes a contract from another but replaces a large aircraft with two of smaller capacity. For airlines seeking to commence a new service their time of operation remains subject to an available slot.”

These local rules also address how multiple bids for a slot in peak periods are prioritised. Cock explained: “Assignment of a slot in peak periods takes account of the operational circumstances of the airlines concerned. For example, a FIFO airline operating to and from an airport with limited infrastructure would be given a priority for a slot that enabled daytime operations.”

Having the slot allocation method taking account of local circumstances has resulted in reduced delays and improved user compliance, compared to the previous Metron-only system. Metron seemed to suffer a backlash from local operators who believed that arriving intrastate operations were disadvantaged due to operations only within 800nm of Perth Airport being subject to flow control.

In comparison, aircraft arriving from interstate are not subject to these controls. At times FIFO airlines would choose to get airborne from a rural airport in contravention of their assigned time to avoid weather or impending darkness when adequate lighting was not available. An airport slot scheme applies equally to all airlines irrespective of their point of origin or destination.

Cock reported initial indications point to approximately a 60 per cent reduction in arrival and a 70 per cent reduction in departure delays with the introduction of SCS. Previously,

A fIfO airline operating to and from an airport with limited infrastructure would be given a priority for a slot that enabled daytime operations. peTer cock - perTh AirporT

Terminal air traffic management has to contend with mixes of aircraft types, and in the case of Sydney Airport protect regional air access. seth jaworski

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airlines could experience departure delays of up to 90 minutes. This delay has now reduced to an average maximum of 15 minutes.

OptimisationACE is a multi-faceted initiative aimed at achieving optimal runway capacity at Australia’s four major airports. It seeks to maximise the aircraft movement rate at Perth, Brisbane and Melbourne.

At Sydney, the goal is to attain the maximum movement cap of 80 per hour. ACE seeks to achieve capacity enhancements by removing inherent inefficiencies that presently exist within various elements of the system. ACE is led by Airservices, but has active involvement from airports and representatives from airlines and non-scheduled users. It is jointly funded by Airservices and the airports.

The first step in the ACE program was the completion of an operational performance and capacity assessment for each of the airports. NATS Consultancy, an offshoot of the United Kingdom’s air navigation service provider, was chosen to provide new thinking to resolve capacity issues and for their experience at Gatwick Airport, which is commonly considered to be one of the most highly optimised single runway operations globally.

Airservices’ executive general

were developed from evaluating current operations and benchmarking performance with two international single runway airports. The end result was a target movement capacity developed for each airport that could be achieved with improvements in the operational efficiency of a number of areas.

Initiatives that provided the most significant opportunity to increase runway capacity were reducing spacing between arriving flights, the adoption of standard arrival speeds and reduced runway occupancy times. For Brisbane, 23 capacity initiatives have been identified. At each airport specific working groups are formed to address the major items.

Of these, the adoption of standard arrival speeds is probably the key element. Standard arrival speeds provide predictability to air traffic controllers who can then have the confidence to reduce the spacing between arriving aircraft. It also enables gaps between arriving aircraft to be more effectively planned to enable departures to take place.

Rick Davies, the RFDS’s head of flying operations and a member of the Brisbane ACE Steering Committee said: “A lot of work has taken place in establishing the appropriate arrival speeds. The issue is complicated due

We are exploring other infra-structure options to increase capacity.mArk WiLLeY – BriSBAne AirporT

manager ATC Jason Harfield explained: “The industry is faced with meeting increasing traffic levels without new airport infrastructure becoming available until at least the end of this decade. To meet these demands we need to extract latent capacity within the existing operations undertaken by airlines, airports and Airservices.

“NATS undertook studies at each of the four airports in early 2012. Their brief was to identify initiatives to maximise the available capacity of existing runways. Initiatives to release latent capacity require all industry players to work together. To implement the host of changes, a strategy and action plan for each airport has been agreed with industry stakeholders. For each airport an ACE steering committee and working groups have been formed to undertake initiatives as well as provide oversight. Membership of the steering committees includes participants from the airport concerned, scheduled and non-scheduled users and Airservices,” Hatfield said.

The NATS studies involved determining the maximum runway capacity and identifying measures needed to increase current performance to achieve this maximum capacity. The process involved a seven-day site visit to review traffic data and observe operations. Performance metrics

Collaboration between airlines, airports and Airservices is key to improving capacity. brenden scott

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In the slot

to the variety of aircraft types and variations in how different airlines operate the same aircraft. For Brisbane, arrival speeds are defined at three mandatory ‘turnstiles’. Aircraft unable to achieve these speeds are required to make greatest speed for as long as possible.” These speed control initiatives are detailed for each airport in ERSA.

Adoption of standard arrival speeds and the need to reduce runway occupancy times have required considerable efforts in crew education. Each airline is encouraged to train flightcrews on standard arrival speed procedures and practices to reduce runway occupancy times. In support of airline training, Airservices has prepared information brochures for users at each airport that include suggestions for flightcrews to adopt as they prepare for departure and preferred runway exit points for arriving aircraft.

At Brisbane, improved utilisation of cross-runway 14/32 would also result in an increase in capacity. Willey said: “The cross-runway can be used by Code C jet aircraft as well as turboprop aircraft. Analysis suggests that up to 15 per cent of peak-hour capacity could be undertaken on this runway. However, following a safety incident in 2010 the regulatory agencies imposed operational restrictions that reduced usage to around five per cent, lower after dark.” An ACE working group is addressing how usage of 14/32 could safely increase.

Considering other possible airport infrastructure enhancements, Willey noted: “NATS’ analysis indicated runway 01/19 is already operating at near maximum capacity. Although Brisbane has two sets of rapid-exit taxiways, we are exploring other infrastructure options to increase capacity. These options will be modelled to determine the benefits from an investment in additional infrastructure.”

From an air traffic control perspective, there is work planned to redesign terminal airspace and revise procedures with the nearby RAAF Amberley.

Airservices is evaluating a ‘Brisbane South Sector’ to improve operations in terminal airspace including ensuring aircraft are stacked at correct intervals on final approach. This involves achieving minimum spacing for a stream of arriving aircraft or ensuring a gap is provided for departing aircraft.

At Perth, evaluation is being

undertaken to analyse a potential investment in additional rapid-exit taxiways (RETS).

“Perth is assessing the benefits that may arise from constructing additional RETS,” Cock said, adding: “ACE initiatives have resulted in more predictable aircraft operating characteristics. It enables more accurate traffic simulations to be undertaken to locate the optimal position of these RETS. SCS also supports this evaluation by providing sound traffic data to base future traffic projections on.”

The successful implementation of ACE initiatives brings a number of benefits that Airservices said could result in capacity increases of between five and 15 per cent without major investments in airport infrastructure. ACE initiatives establish consistent aircraft operating characteristics to provide greater accuracy in assigning arrival and departure rates used in Metron and the airport slot management schemes. NATS is scheduled to return in early 2014 to undertake a program review.

A critical element of these capacity enhancement programs is the introduction of daily reporting of system performance at each airport. Harfield emphasised the importance of this initiative.

“Airservices has appointed a senior manager to review system performance and coordinate initiatives with airports and airlines as well as the air traffic

control operation. The process involves gathering data on performance metrics daily and reporting results to stakeholders.”

Rick Davies added insight from a pilot perspective: “Airservices is recording and providing accurate detail to airlines. An airline could identify the specific flight that has not complied with required procedures. Having operators receive performance metrics and levels of compliance will inevitably drive further operational improvement.”

Perth and Brisbane airports are also collecting their own performance metrics daily from their slot management schemes. Both airports are assigning additional staff to this measurement and reporting process, with the data shared with Airservices and airlines, while compliance issues are addressed with the operator concerned.

One of the most significant benefits from the initiatives to better balance aircraft demand with the system capacity has been the manner in which airports, Airservices and airlines have collaborated. Harfield provided an Airservices perspective.

“A significant paradigm shift has taken place in how the various industry groups have worked together. Each has a better understanding of the issues, how the problems can be resolved and their role in solving capacity problems.”

Slots for international services need to take into account many factors including slot availability at other airports. seth jaworski