DAVID LEARMOUNT / LONDON
Instructing pilots via datalink rather than by voice is the way ahead for ATM. But the hard part is convincing users to invest
By 2007, Europe's busy skies should start to get noticeably quieter. That is, the amount of voice communications chatter should begin to reduce even if the number of aircraft is increasing.
This is the intended outcome of Eurocontrol's Link 2000+ programme - a controller-pilot datalink communications (CPDLC) system that will replace many of today's voice exchanges with the transmission of data by datalink. In four years' time, however, it seems that only a few of the aircraft using European skies will have equipment conforming to the agreed standard, known as VHF datalink mode 2 (VDL-2).
The problem for Eurocontrol's director general Victor Aguado in launching Link 2000+ is that, until a critical mass of control centres, airports and aircraft are equipped, the advantages - greater safety and improved air traffic management (ATM) system capacity - will not materialise.
Aguado says that when 75% of aircraft are equipped with VDL-2, the resulting controller workload reduction will enable them to handle a capacity increase of 11%, which translates into a 40% reduction in delays. The airlines would certainly pay for a benefit like that. Aguado's problem is that investment is needed today to achieve benefits tomorrow, and airline accountants are not in an investing mood.
Link 2000+ programme manager Alex Wandels has not ventured a date for achieving 75% equipage, but he has hinted at 2010 as a year by which datalink might be mandated, if pressure on capacity and a slow voluntary adoption rate force it. Meanwhile, by 2007, when Eurocontrol knows its Maastricht air traffic control centre (ATCC) and most of the neighbouring sectors will have the necessary ground capability installed, Aguado will be pleased if any airlines - apart from those persuaded to take part in the Maastricht operational trials beginning in April - have voluntarily equipped.
If previous programmes - such as the recent implementation of reduced vertical separation minima - are any indicator, Eurocontrol member nations will begin to confine non-datalink aircraft to flight levels below 29,000ft (8,850m), which is a fearsome motivator for laggards.
Reluctance to invest
Aguado recognises that airlines are reluctant to invest in any new equipment without a sturdy business case. So Eurocontrol is planning European Commission-backed financial incentives for the first airlines to equip. It would begin with Eurocontrol paying the €20,000 ($21,500) per aircraft cost of equipping the first 100 airframes (those in the airline fleets taking part in Maastricht's trials) with VDL-2. After that, reductions in ATM system user charges are on the cards, but the formula has not yet been worked out.
Another incentive to install VDL-2 is that the datalink many airlines use for their own management and engineering messaging - the VHF aircraft communications addressing and reporting system - will soon be saturated, and the broader band VDL-2 has more capacity to do the same job as well as the ATC task. This, says Eurocontrol, is one of the reasons VDL-2 was chosen as the first stage system.
Martin Cole, a US controller writing in the International Federation of Air Traffic Controllers Associations magazine The Controller, is worried about an airline push to have the FANS-1/A datalink - designed for use in oceanic regions - accepted for "high-density continental airspace" where it will not meet specifications. Wandels is adamant this will not be permitted in Europe, at least not in the medium or long term.
Not all Maastricht's contingent flight information regions (FIR) are committed to be ready for VDL-2 by 2007 (see chart). For example, the Maastricht FIR's largest single boundary is with the London FIR, but the UK's new Swanwick area control centre began its long design phase before the CPDLC datalink mode had been agreed, and George Ennis, UK National Air Traffic Systems (NATS) head of air traffic operations policy and performance, admits that its flight data processing system (FDPS) is incompatible with VDL-2. However, many of the safety functions that the CPDLC datalink can carry out can be done by Mode S secondary radar, which is a datalink in its own right (see panel, left).
Mode S is replacing Mode C secondary radar, first of all in the London terminal manoeuvring area and later more widely. Mode S can, for example, provide controllers with predictive flight plans for the aircraft based on interrogation of the aircraft's flight management system (FMS), and can compare cleared trajectories with selected trajectories in the FMS, which certain functions of VDL-2 CPDLC will also be able to do.
Ennis has not released a date for Swanwick FDPS replacement, but says NATS is "reviewing a number of options from several manufacturers". What is clear is that, when it opens in early 2009, NATS' new Prestwick ATCC in Scotland will be the organisation's first venture into full integration with all the parameters set by Eurocontrol for the future Single European Sky (Flight International, 28 January-3 February), and Swanwick's upgrading will have to be soon after Prestwick goes operational if Wandels' estimate for a mandating date remains at 2010.
Europe committed
Meanwhile, Maastricht's immediate neighbours Germany and France are committed to VDL-2 by 2007, and so are Austria, Italy, Norway, Spain (including the Canary Islands) and Switzerland. So what Wandels calls "core Europe" will be equipped.
The USA is heading down the same road, also with VDL-2 as the chosen tool for its CPDLC. Therefore transatlantic harmony has been achieved, which bodes well for international standards as set out by the International Civil Aviation Organisation.
Cole insists that international standards are essential to persuade airlines to invest in equipment, because they cannot afford to equip differently for different parts of the world.
The Federal Aviation Administration has arranged for Miami's area control centre to take the role of CPDCC initiator, as Maastricht is doing in Europe, but in the USA there will be no incentive programmes for the airlines and, the FAA promises, no mandating - ever.
Source: Flight International
