As free flight comes closer to reality, all parties involved in the concept find the final details difficult to agree.

Julian Moxon and Kevin O'Toole/AMSTERDAM

Few concepts have caught the aviation industry's collective imagination as strongly as that of "free flight". The prospect of aircrews being able to chart their own way in the skies, cut free from their ties to ground-based air-traffic-control (ATC) systems, certainly holds its fascination. Some are already prophesying that free flight will create as fundamental a sea change as the emergence of the jet aircraft half a century ago.

One definition of the concept describes the flexible use of airspace as "-no longer designated as either military or civil, but considered as one continuum and used flexibly on a day-to-day basis. Any necessary airspace segregation should consequently be only of a temporary nature."


Flight International's Airline Navigation '96 conference, held in Amsterdam, Netherlands, on 9-11 October, certainly captured much of the fervour, which is spurring on the debate. Yet it also revealed much of the growing frustration about lack of progress in introducing the communications, navigation, surveillance/air-traffic-management (CNS/ATM) technologies which will lie at the heart of the future system.

Much of the technology required to put the concept into practice is already potentially available and developing fast. All agree that the end-point of freer - if not entirely free - flight is the worthy objective. At the root of the problem is the sheer scale of the free-flight concept. It will require heavy investment by the airlines and air-traffic-service (ATS) providers, not to mention a radical change of culture.

Clearly, no type of investment makes sense without the other. Airlines are deeply reluctant, to spend hard cash on cockpit technology for, which there is no guarantee of an operational payback. Equally, the ATS providers have little to gain from investing in the necessary infrastructure to make that possible, without reassurance that they will not be left with a white elephant. Regulators, too, have yet to face up to the complexities of certificating FANS.

The aircraft and systems manufacturers are already committed to developing the technology, but have few clues as to, which of the competing solutions will eventually reap the reward of a massive new world market.

In short, the free-flight concept is in danger of becoming becalmed, amid a sea of possible technical solutions without a clear next step. The frustration at this lack of leadership is perhaps more galling because of the potential multi-billion-dollar savings to airlines and ATS providers alike if and when traditional ground-based ATC can finally be switched off. The US Federal Aviation Administration alone estimates that it would save $240 million annually from no longer having to maintain its existing VOR stations.


David Allen, Boeing's CNS/ATM manager, argues that concentration on such long-term benefits and big-picture technological advantages may actually be hampering the prospects of getting started with implementation.

He argues that the people who hold the final sway over practical implementation of CNS/ ATM in the cockpit are not engineers or flight operators, but airline financial officers. These "coldly cynical financial types", he says, need to be shown evidence of specific short-term savings rather than long-range "notional" benefits.

Allen's crusade to bring CNS/ATM back down to earth is backed by Boeing's own experience with the FANS 1 package for the 747-400, now in operation on the Pacific and earning its way with clear fuel savings.

Boeing had initially opted for a state-of-the-art package, with a host of sophisticated technologies. It failed to sell and was withdrawn. The system's cost, combined with a lack of mature benefits, made airlines wary. The lack of infrastructure to support the sophisticated communications and data-linking technology did not help the equation, says Allen.

In response, Boeing cut down on cost and technology, to re-emerge with the FANS 1 package. Even then the implementation only came after Boeing and the airlines sat down to develop business cases for the system on specific route structures where the necessary infrastructure development was guaranteed.

Allen argues that development of such business cases crucial if the CNS/ATM industry is to take the next step. "The industry is getting to the point where the achievement of business- case maturity may be more important than technical maturity," he says, warning that technicians must avoid the temptation to "gold-plate" their systems.

Allen believes that the way ahead is to use such specific business cases to build a broader industry plan of action, which should include the ATS providers supplying the necessary ground infrastructure.

In part, the task is being tackled by the CNS/ATM Focused Team, a group, which brings the airframe manufacturers (Airbus, Boeing and McDonnell Douglas) together with a cross-section of airlines (American Airlines, British Airways, Qantas and United Airlines). The aim is not to look at new technologies, but to develop a way of evaluating the constraints on capacity and efficiency within the world's main air-traffic regions and to identify the operational improvements which are needed to overcome them.

The starting point is to look at the action plans already in place around the world (see diagram), such as the US Free Flight Action Plan or The European ATC Harmonisation and Integration Programme.

A model is being developed for each of the regions, to map out various groups of initiatives and their likely impact on capacity/efficiency. Eventually, the aim is to build an overall regional plan of action for phasing in improvements. The priorities will then be determined by a cost/benefit analysis. Initial reviews of the first such prioritised plans are due to be held with industry in the first quarter of 1997.

Eventually, by drawing together these regional plans, Allen says that an overall industry strategy should emerge, to be used by airlines and air-framers to decide which operational enhancements should be pursued. ATS providers too could use the plan to co-ordinate timing for infrastructure enhancements. Most importantly, each phased step along the way will be backed by a business case, which can be put to airlines' financial officers.

Along the way, Allen warns that economic arguments may doom some of the "pet technologies" now being championed. It remains to be seen how easy it will be in practice to persuade others to let go of their preferred technologies and concepts in the name of consensus. There are also a growing undercurrents of concern about just how prepared the ATS providers really are for the massive cultural change which free-flight concepts will inevitably bring.

"CNS/ATM will change the world," says Graham Lake of SITA. He admits that the "big bang" is perhaps still a decade away, but believes that the initiatives being carried out today must be in the context of a future global solution. SITA's own efforts towards building a global communications network to support CNS/ATM have run up against a frustrating lack of a long-term sense of direction.

The very act of freeing the world's airspace must result in the ending of many of the traditional divisions between air-traffic regions. "There is no such thing as an autonomous solution on a national or regional basis. They should be global solutions which are then applied regionally," he says.


Lake cites the European ATM System (Eatms) initiative, which will have to work alongside a system, which provides end-to-end direct routing between points in Europe and the rest of the world, and should therefore be seen as a global system. "It is a huge issue that airlines and air traffic control bodies have not faced up to yet", he says.

Not least is the issue of sovereignty over national airspace, which many within the ATS community privately warn is storing up a storm ahead. In technological terms, the future would seem to lie in regional systems, without a clear role for individual ATS providers.

In North America, the FAA is already in a position to provide the necessary regional solution and infrastructure. Despite the recent highly public contract and funding problems surrounding implementation of the Wide Area Augmentation System (WAAS), the FAA remains confident that it will be able to start turning off VOR stations within the next few years, as the global-positioning system (GPS) becomes usable as a sole means of navigation.

Dan Hanlon, the FAA's project leader for GPS Operational Implementation, also seems confident that the FAA can win its battle to fund the Local Area Augmentaton System for landing and approach, although he admits that, "in reality", the existing instrument-landing system is unlikely to be switched off until at least 2010.


More problematic is the issue of who will take up leadership of a similar campaign in Europe. The region's need to increase the capacity of its heavily congested airspace is beyond doubt.

The driving force behind the introduction of what Euro-control calls flexible use of airspace (FUA) is the need to relieve mounting congestion, and the resulting delays. "It's a simple question of economics," says an industry source. "Free-flight technology is an essential element of the battle to overcome the lack of available airspace". With air traffic expected to double within the next 15 years, it is clear that action is necessary.

Latest estimates from Euro-control suggest that implementing a a free-route concept across its air space above 33,500ft would yield an annual benefit of more than Ecu500 million ($622 million) (see table). The figure rises to Ecu640 million if taken above 29,500ft, says Klaus Dieter Ehrhardt, who has been heading strategic-infrastructure planning for Germany's air-navigation service, the DFS.

Yet while the technologies for FUA are now largely available, institutional questions on matters such as certification, regulation and safety have yet to be addressed seriously. "The regulatory status of these far-reaching navigation initiatives are misunderstood," says the s Kim O'Neil of the UK Civil Aviation Authority. "At present, airlines have very different views on what they should be doing about installing a cost-effective, legal, navigation system for the future ATM/CNS environment".

According to O'Neil, the certification issue needs to be "urgently addressed". CNS/ATM technologies involve a level of co-operation and integration between ground and avionics elements not covered by existing certification processes. "Global implementation of these technologies means that, for example, the [automatic dependent surveillance - broadcast (ADS-B)] infrastructure must be fully integrated across national boundaries," he adds. The difficulty of achieving international certification is such that introduction of the flexible use of airspace "-may be impeded", says O'Neil.

He believes that a clear picture may be emerging, however, on how the necessary standards should be developed. "There's a lot of material already, but there are bound to be big political and economic battles about whose solutions on things like network standards should prevail," he says.

The European problem is exacerbated by what SITA's Lake describes as a "mountain of institutional problems". No single body has the power to push through the necessary measures.

The European Joint Aviation Authorities still has no legal power, says O'Neil. Euro-control is increasingly present in the development of regulations and of CNS/ATM technologies to allow gate-to-gate flexible use of airspace, but it is not a certification authority and has (as yet) no rule-making mandate. "We still need to clarify their role," says O'Neil.

One suggestion is that the European Commission (EC) could become an Euro-control member, making it a regulatory body, with the Commission having a casting vote.

The EC itself warns that, if "-Europe does not act promptly, control of the entire system will be done from overseas-user requirements, standards and certification will be set by those that own and operate the system". The FAA's progress on the WAAS, and its open invitation for other regions to participate in using the system, is clearly being interpreted as a wake-up call.

The UK CAA also raises important questions about safety, again because the various elements, which go to make up CNS/ATM are, because of the international context, not overseen by any single body.

"How does the ATS provider prove it can offer safe service to his authority?" asks John Pumfrey, who heads a team developing safety requirements for future ATM systems. "There is no mechanism at present to allow cross-judgement of each country's safety case. It is a big problem, because it needs to be quick and effective - the airlines won't tolerate a mega-body," he adds.


Pumfrey suggests that special "functional teams" are needed to cut across the spectrum of ATM issues, possibly working under the International Civil Aviation Organisation.

The phenomenal quantity of software inherent in the latest ATM systems, and the various languages they use, pose another problem. "How does the regulator cope?" asks Pumfrey. The UK is looking at the idea of third-party assessment of safety measures, with more emphasis on analysis of safety and performance trends. "We need accident, but also incident, data," he says. The CAA is looking for partners with which to develop its "safety-case" approach to safety at complex ATS systems such as area control centres.

As with so much of the current FANS debate, the major hurdles to overcome may prove more cultural than technical.

Source: Flight International