ATC Technologies

 - October 4, 2007, 5:58 AM

Sharp rises in the number of airline flights originating from airports in the U.S. and Europe are presenting FAA and Eurocontrol officials with some daunting challenges. Chief among these is the question of how to squeeze more capacity from airports and ATC route systems that in some places already seem stretched to the breaking point. But somewhat surprisingly, instead of joining forces to confront mounting delays and airspace congestion, the U.S. and Europe are on divergent paths, with the U.S. following its so-called Flight Plan 2004-2008 for ATC modernization and Eurocontrol moving aggressively to implement the Single European Sky (SES) initiative.

It is a race that neither side can afford to lose, especially in the face of higher traffic levels caused by steadily improving economies and the influx of regional jets. Air traffic in the U.S. and Europe has returned to pre-9/11 levels. On both sides of the Atlantic, airlines now seem poised for another period of sustained growth. The main challenge in the next several years for Europe will be shaping the ATC route system to deal with an end to the national boundaries that have impaired its efficiency in the past. The Single European Sky plan is in full swing, with a number of important contracts and milestones coming in the months and years ahead.

The FAA’s Flight Plan is a to-do list through 2008 that the agency adopted from the business world. Notably, all of the targets are employee goals with employee bonuses tied directly to meeting these goals. The ambitious objective is to meet at least 90 percent of the goals–for instance, achieving 27 out of 30 objectives. If the FAA employees who are involved in the modernization projects do that consistently, they will receive raises. If they miss the targets, they will not.

Last quarter the FAA was right on target, hitting 90 percent precisely. This quarter, however, the number dropped to 22 out of 30. Two targets–airport arrival efficiency and on-time arrivals–were in the red zone, meaning that the FAA is not likely to meet them this year. Six other targets were deemed yellow. “With a lot
of work, they can still be brought to green by the end of the year,” said FAA Administrator Marion Blakey.

The good news is that there have been no fatal airline accidents so far this year. In fact, the fatal accident rate for commercial aviation in the U.S. is the lowest in history. Still, the FAA admits there is considerable room for improvement and much work ahead to meet modernization goals.

U.S. ATC modernization on a slow, bumpy course

After more than 10 frustrating years of technical delays, escalating costs and contractor switches, the FAA’s GPS wide area augmentation system (WAAS) is now approaching the level of performance originally envisioned in the late 1980s. With the system’s initial operational capability declared last year–and a year of satisfactory performance now behind them–WAAS advocates can see much more light at the end of the tunnel. And while there are a number of important program milestones still ahead, WAAS avionics units are now entering the marketplace, allowing pilots to start sampling some of the system’s promised benefits, such as WAAS guided LNav/VNav approaches and, when procedures become plentiful next year, “near Category I” localizer precision with vertical guidance approaches down to 250 feet.

This year and next, 13 additional ground-based GPS monitoring stations are planned–five in Alaska and four each in Canada and Mexico–to supplement the present 25 stations across the continental U.S. and to further expand system coverage. The ground stations gather incoming signals from the GPS satellites and, after processing, their results are sent up to very-high-altitude geostationary satellites (GEOs) and re-broadcast down to users as accuracy corrections and failure alerts.

By 2007, when two new GEOs are forecast to be operational, providing redundant “umbrella-like” coverage over most of North America, agency officials expect to declare that the system has attained full operational capability. Looking even further ahead, the FAA aims eventually to have WAAS provide full, ILS-equivalent, Category I service across the continental U.S.

This is a remarkable turnaround for a program that, throughout its 10-year gestation, frequently appeared to be teetering on the brink of cancellation. Even from its beginning in 1995, things looked distinctly unpromising, with the FAA terminating its initial development contract award to Wilcox Electric for non-performance after only nine months.

Transfer of the contract to Hughes Electronics, and later to Raytheon, brought things back on the rails, but not without serious problems in achieving the required levels of signal integrity, causing major delays in commissioning. And all the time the dollar clock kept ticking. In 1994 the FAA estimated that WAAS development, production, implementation and follow-on operations and maintenance costs during the system’s planned 20-year life would total $1.4 billion. One year later, Wilcox estimated the total to be $1.8 billion. Hughes upped that to $2.4 billion, and Raytheon’s entry raised it to $3 billion.

Currently, unofficial estimates put the bill at around $3.2 billion, although some FAA officials suggest that this could eventually shrink by as much as $500 million. Yet others are skeptical. “We may never know how much WAAS has really cost,” one senior Department of Transportation official told AIN, “But it’s hard to believe it can possibly go below $3 billion.”

Betting on WAAS
Will WAAS pay off? That’s a hard question to answer. The original intent was that WAAS would augment DOD’s GPS with the signal integrity necessary to meet FAA navaid standards, thereby paving the way to “sole means” satellite navigation, which in turn would allow the FAA and the user community to gradually remove traditional ground-based aids and avionics systems, with substantial cost savings. But the events of 9/11, coupled with the acknowledged vulnerability of GPS to deliberate jamming, caused a rethink of this policy, with the recognition that back-up systems will remain necessary. (One exception is in Alaska, where WAAS- equipped Capstone aircraft are exempt from carrying back-up systems.) On the other hand, the safety benefits of WAAS, particularly in approach and landing operations at less well equipped airports, cannot be underestimated. ICAO’s endorsement and adoption of the WAAS concept–known generically as an SBAS, for satellite-based augmentation system–underscores the safety benefits of WAAS. Moreover, the FAA’s initiative has been followed by Europe’s EGNOS, Japan’s MSAS and other regional systems, all receiver-compatible with the original FAA concept.

A key issue that has recently arisen is whether WAAS will, in fact, displace the GPS local area augmentation system (LAAS) as the nation’s future Category I precision approach aid. This was one of the original WAAS goals when the program was conceived in 1994, when it was forecast to achieve Category I by mid-1997. Subsequent changes in contractors and in program priorities saw this date steadily slip until, in November 2003, an FAA official testified before a Congressional subcommittee that this part of the WAAS program had been canceled, thereby yielding significant cost savings. However, in January the FAA canceled the LAAS program, relegating it to a research and development endeavor.

Perhaps as a result, the FAA Joint Resources Council (JRC)–the agency’s senior decision-making body–in May “re-baselined” the whole WAAS project and reinstated its Category I component, under its revamped name of the GNSS landing system (GLS). The JRC also extended the WAAS operational life to 2028, but would commit only to “expecting” GLS implementation by 2013, when it would use “dual GPS frequencies.” This term refers to the signals that the next generation of GPS satellites, forecast to start to enter service in 2013, will transmit. Called L1 and L5, these two frequencies are far enough apart in the radio spectrum that ionospheric activity, which is now the major cause of GPS accuracy errors, will affect them quite differently. Comparing the different ionospheric effects on L1 and L5 allows them to be canceled out in the receiver. WAAS uses a different ionospheric correction technique to achieve the same results.

And this has now raised an interesting question among industry observers. Since dual-frequency operation will become standard on the next generation of GPS satellites starting in 2013, and also with Europe’s Galileo satnav system, forecast to become operational around 2010, and with both systems designed to provide high integrity and quick failure warnings, some observers now ask whether WAAS will become redundant long before the 2028 date the JRC envisions.

ICAO has endorsed automatic dependent surveillance-broadcast (ADS-B), originally conceived for use in remote areas and specialized operations, as a key element in the world’s future air traffic management system.

The FAA’s first Alaska Capstone project in 2000 evaluated ADS-B’s ability to provide “near NAS quality” services to small commercial aircraft flying at low altitudes beyond the reach of VHF communications and below ATC radar coverage. Centered in Bethel in western Alaska, Capstone I has more than 200 participating aircraft. Bethel once had Alaska’s highest aircraft accident rate but, because of ADS-B, accidents have dropped 40 percent, making it the region with the lowest rate.

Capstone II, also involving 200 aircraft, is currently under way in the Juneau/Ketchikan region of southeast Alaska. Capstone III, as yet unfunded, will extend ADS-B across the rest of the state. A U.S. East Coast ADS-B network is also being installed, with “pockets of implementation” planned for other locations starting at Prescott, Ariz., where Embry-Riddle Aeronautical University is equipping 40 training aircraft. At its Daytona, Fla. campus, the university is equipping 60 aircraft.

ADS-B has many applications. Embry-Riddle plans to use it to help students see and avoid other aircraft. Conversely, freight carrier UPS wants it to assist pilots in closing large gaps between aircraft arriving at its cargo hubs during overnight “rush hours.” And at Juneau, Alaska, ADS-B map displays will allow snowplow drivers to see arriving and taxiing airplanes in low-visibility conditions. ADS-B has also been tested in aircraft transiting the Gulf of Mexico, where widely spaced “procedural” separations are imposed outside ATC radar coverage. ADS-B “pseudo-radar” reports to the ARTCC could alleviate this problem. Australia is adopting ADS-B across its vast uninhabited interior, for the same reason.

Yet while ADS-B’s benefits are clear, opinions differ about its optimum datalink. Three different links are available: the mode-S transponder-based 1090ES (1090 for its 1090 MHz frequency, and ES for its “extended squitter” ADS-B signal bursts); the U.S.-developed Universal Access Transponder (UAT); and Sweden’s VHF Data Link Mode 4 (VDL-4). According to ICAO, “Each has relative advantages over the others with regard to some criteria.”

Air carriers support 1090ES, since their mode-S transponders are modifiable to that standard, and the FAA, Eurocontrol, Australia and the Asia Pacific nations have correspondingly adopted it. However, the FAA also supports UAT for Capstone and for general aviation, and its ADS-B ground stations will handle both 1090ES and UAT. Mode-S antennas can also carry UAT signals. But VDL-4’s VHF frequency would require separate, dedicated antennas on mode-S- or UAT-equipped aircraft, making it less attractive for worldwide use.

Nevertheless, as we move into the 21st century, ADS-B seems set to become the foundation of the world’s future air traffic management system, bringing enhanced safety, improved surveillance, increased capacity and other benefits.

Pilots flying into Milwaukee’s Mitchell International Airport may not realize that their every movement–approaching, landing, taxiing in and then taxiing out and taking off–is now being monitored more closely than ever before. But not for national security reasons: it’s actually part of the FAA’s war on runway incursions. Eight small, unmanned sensor units arrayed around the field, key components of the latest airport safety technology, perform the upgraded monitoring. Officially called multistatic dependent surveillance, or multilateration, and aimed at reducing surface accidents, the system’s potential application to other aviation tasks could well earn it the sobriquet of ATC’s Swiss Army Knife.

Multilateration uses the principle once called triangulation, where bearings or ranges of an object from three separate locations would establish its position. In today’s system, the sensor units around the airport continuously listen for all transmissions from aircraft mode-A, -C or -S transponders, TCAS, ADS-B and even military IFF units. When these signals are received, they are computer processed to precisely pinpoint their source.

The multilateration system is the brain behind the FAA’s ASDE-X program, where it is combined with a new surface detection radar. Built by Sensis, the Milwaukee installation is the first of 33 ASDE-X systems to be progressively installed at major airports in the NAS. Sensis multilateration equipment is also installed at London Heathrow, and has been ordered by several large European airports and by the U.S. military.

The major benefits of multilateration are its precision–it has much higher accuracy than radar and is claimed, in fact, to be more accurate than GPS–and its once-per-second target tracking rate, almost five times faster than terminal surveillance radar and 12 times faster than long-range en route radars. But the equipment does not need to be combined with radar, which gives it the flexibility to be applied to many other operational tasks at significantly lower cost.

For ATC and pilots multilateration has some even more intriguing operational benefits. Under a NASA contract, Rannoch has developed a cockpit runway incursion display that gives pilots the same alerts as the tower’s ASDE-X.

Europe realigning for a 'single sky'

Air traffic in Europe has returned to pre-9/11 levels and seems set for another period of sustained growth. This time it will be in the context of an ATC system preparing to cope with an end to the national boundaries that have impaired its efficiency, one that is on the verge of introducing various forms of data communication and that can look forward to benefiting from a new and better satellite navigation system.

Pascal Dias, head of Eurocontrol’s air traffic services division, said he believes that ATC will continue to be a human-centered activity for the foreseeable future. It will, however, deal increasingly with intents and trajectories. There will be a greater emphasis on air/ground cooperation, and trajectory information will need to be shared among aircraft as well as with controllers on the ground.

“As far ahead as we can see, ATC will remain a human-centered activity, and generally speaking it will be based on providing the human participants with more informed and distributed decision processes,” Dias said. “So it’s about what is sometimes referred to as system-wide information management.”

It is also likely to involve better cooperation between air and ground. The agency has developed a concept called cooperative air traffic services, which Dias describes as “a base for our activities in trying to better scope the interactions between the ground and the aircraft, and also trying to approach the potential sharing of responsibilities between the controllers and the cockpit.”

At the same time, where currently ATC is based on an understanding of the present situation and aircraft positions, it will move toward a better understanding of intents and trajectories. “It’s likely that interactions with ATC will be manipulating the trajectories and not only the positions,” Dias said. The current ATC system does that to some extent by modifying headings, waypoints or altitudes, but “we expect these trajectory-based interactions to intensify.”

Overall Architecture
One major focus for Eurocontrol’s activities, and one supported by the European Commission (EC), is the Overall ATM/CNS Target Architecture (OATA) project. Aimed at defining a high-level architecture to support future concepts, particularly in the context of the EC’s Single European Sky initiative, OATA has been running since the beginning of last year and is scheduled for completion by the end of next year.

The results should be available in time to support the realization of the SES, initially by ensuring the progressive convergence of existing systems. Ultimately it will constitute the reference ATM/CNS architecture for all new implementations from 2011 on.

One aspect of OATA, Dias said, relies on the European Organisation for Civil Aviation Equipment (EUROCAE) to help Eurocontrol define an industry standard for implementing the architecture: “The Single Sky principles see Eurocontrol helping the overall regulation process with some implementation rules, but also the industry being involved through EUROCAE in developing the industry standards.”

Rather than issue mandatory specifications, Eurocontrol will issue standards that will define best practices from the industry side to support the implementation of the rules. “We’ve initiated a strong cooperation with EUROCAE on those matters, including architecture,” Dias commented.

The organization is taking a new interoperability approach toward another key component of the future air traffic management system, namely flight plan processing systems. These ground systems need to be able to interoperate so that they can support trajectory-based ATC, with deconfliction well in advance and traffic spread among a number of centers.

Last year Eurocontrol awarded Spain’s Indra ATM a contract worth up to $60.04 million (449 million) to develop a new flight data processing system for its own upper area control center (UAC) at Maastricht. Scheduled to become operational at the end of 2007, the system will be based on requirements developed by the European flight data processing program (eFDP).

The Maastricht center manages traffic in the upper airspace (above FL245) of Belgium, Luxembourg, the Netherlands and northwestern Germany. The new FDPS is expected to help deliver improved interoperability, trajectory prediction to provide four-dimensional flight paths and map them onto the airspace structure, controller pilot datalink communications (CPDLC) and direct routing and dynamic route changes, among other benefits.

For Germany’s DFS, Indra and Raytheon developed the very advanced FDP operational requirements implementation (VAFORIT) under a contract awarded in 1999. The VAFORIT integration release software was handed over last December; the Release 2 software was due to follow this year, adding improvements such as enhanced mode-S and medium-term conflict detection (MTCD).

Thales and Finmeccanica-BAE Systems formed joint venture AMS last year to develop a new FDPS for the French and Italian air navigation service providers, DNA and ENAV. Known initially as eFDP/fi, for eFDP/France Italy, and estimated to be worth more than $122.5 million (4100 million), the program adopted the name Coflight (short for cooperative flight) last month, when Switzerland’s Skyguide joined its two neighbors.

At the time of the original contract, Thales and AMS said the flight-plan software would be designed in 20 fine-grain components offering standardized interfaces. Predicted benefits were improved performance, scalability, enhanced safety capabilities and adaptability to customer needs, providing for easier migration and adaptations to European ATC centers.

Another major initiative just getting under way is the Dynamic Management of the European Airspace Network (DMEAN). “We hope this will be a new program,” Dias said. “It’s about managing the airspace in a more dynamic way, and it’s trying to achieve the benefit in the short term, say 2007-08. One key component of it is a proper implementation of flexible use of airspace together with the proper dissemination of flight planning information.”

DMEAN would also involve Eurocontrol’s central flow management Unit (CFMU), which replaced five regional flow management centers in 1996 and represents one
of the first major successes in European air traffic management cooperation.

Properly updated flight plan information shared among all the participants is one of the major elements of the DMEAN concept. The idea is to identify specific ATM problems and facilitate capacity planning and route network optimization on the basis of information shared by both civil and military airspace users.

In the longer term, Dias said, “we will look at exchanging flight data information that is more accurate, more up to date and more dynamic than just updated flight plans. In this context the exchange of trajectory or trajectory elements with the aircraft or with the airline operations will be important.”

The methods for exchanging those trajectory elements and the ways in which they can be incorporated into ATC procedures and clearances require further development. “But we are definitely going toward an ATC system that will be based on proper understanding and knowledge of trajectories so that the decision support tools can be based on that,” Dias said. “And there will be exchanges so that the trajectory is shared with the air component, with the flight management system or airline operations centers.”

ADS-B and Cascade
Sharing intent information is one of the functions of automatic dependent surveillance-broadcast. But while ADS-B can be used to broadcast next-waypoint and similar information, it is essentially just a spontaneous exchange of information. “It is one of the mechanisms that will be used for the exchange of trajectory elements,” Dias said, “but it is very difficult to exchange trajectories on a broadcast basis because the frequency band will be completely overloaded. So there will be point-to-point exchanges and there will be broadcast activities, but the broadcast activities will be limited to next waypoints in the current concept.”

Both ADS-B and the mode-S secondary surveillance radar (SSR) datalink use the same airborne equipment in the shape of the mode-S transponder. The SSR frequency will be the first datalink medium for ADS-B, Dias said, but if that band becomes overloaded there will be a need for other datalinks to complement it.

“For that we still have technology options,” he said. The most established of these are the VHF digital link (VDL) Mode 4 and universal access transceiver (UAT), and research activities are being pursued to decide which would best support ADS-B functions in the future.

Dias said Eurocontrol is keen to develop the approach under its Cascade program (it stands for cooperative ATS through surveillance and communications applications deployed in ECAC, or the European Civil Aviation Conference, which is the body on which the 41 European national government transport ministers are represented). Cascade aims to exploit ADS-B technology to deliver additional benefits. It focuses primarily on improving the surveillance function, but is also intended to make possible some new ATC procedures that would involve aircrew participation.

One example is the delegation to the pilot, supported by appropriate avionics tools, of some of the functions involved in sequencing and merging traffic. That would probably form part of the second stream of implementation, anticipated to begin after 2010. Before that, operational trials beginning next year are expected to lead to the implementation from 2008 of the first stream, addressing the limitations of radar-based surveillance and introducing the facility to transfer routine air/ground communications from voice to data channels.

While Cascade looks to the future, a longer-running program in the surveillance domain continues to make progress. The ATM surveillance tracker and server (ARTAS) technology, which is designed to fuse all types of surveillance data from different sensors into a seamless and accurate air situation picture, has been under development since 1993. The first operational version, V3U, was introduced at the Netherlands ACC at Schiphol in 1998.

ARTAS V4, which added remote supervision capability, became operational at Schiphol, the Maastricht UAC and the Lisbon ACC in 2001. The current operational version is V6b2, which adds the capacity to process elementary mode-S radar information and has been introduced recently at those three centers.

In June Eurocontrol announced that five more centers–Brussels, Dublin, Geneva, Shannon and Zurich–had recently introduced the baseline version of the system. The next version, V7, will enable enhanced surveillance sensor information from mode-S radars and ADS transmissions to be processed: a Unix version was due to be delivered last month, followed by a Linux version in the middle of next year.

Eurocontrol’s program for implementation of CPDLC, Link 2000+, is based on VDL-2 and aeronautical telecommunications network (ATN) technology. To encourage operators to equip their aircraft to use the link, Eurocontrol has provided testing support and financial assistance amounting to $24,506 (420,000) per aircraft for the first 100 aircraft. The organization reached that milestone in January, when Air Europa, FedEx Europe and Hapag Lloyd joined American Airlines, Finnair, Lufthansa, SAS and Airbus Transport in committing aircraft to the program.

Avionics required include a VHF data radio implementing VDL-2, an audible or visual alerting mechanism to notify aircrew of a message’s arrival and a means of displaying messages and selecting responses. The last can be provided by modifying the multifunction or datalink control and display unit (MCDU or DCDU) or using a dedicated keyboard and printer. The communications management unit (CMU) or air traffic services unit (ATSU) also needs to be upgraded with software containing the CPDLC and context management (CM) applications used to encode and decode the messages and the ATN end system and router protocols.

Baseline CPDLC services are datalink initiation capability (DLIC), ATC communications management (ACM), ATC clearances (ACL) and ATC microphone check (AMC), which lets controllers up-link an instruction for all aircraft to check that they are not inadvertently blocking a given voice channel.

An aircrew initiates DLIC on first contact with an ATC unit that supports data communications. A prerequisite to the operational datalink services, it enables flight plan and aircraft address to be associated in the ATC system. Information provided to the ground system comprises airframe identification, aircraft identification, supported air-ground datalink services, departure airport, destination airport and estimated off block time when available.

ACL enables aircrew to request and controllers to deliver en route clearances such as level (including constraints based on time, position or vertical rate of change), heading, speed (IAS or Mach), direct route and rate of climb or descent. It also caters to SSR code change instructions and provides acknowledgments in both directions.

The current sector controller uses the ACM service to transfer ATC communications to the next sector. As well as supporting the transparent transfer of data communications, in synchronization with the transfer of voice communications, it retains the operational principle that there is only one controlling authority, and that the controlling authority is identified properly and unambiguously.

Link 2000+ will also support legacy datalink services such as departure clearance (DCL), downstream clearance (DSC) and the digital automatic terminal information service (D-ATIS) that have been introduced already at some airports for delivery over the aircraft communications addressing and reporting system (ACARS). They are expected to migrate gradually to VDL-2 and ATN as more aircraft are equipped, but Eurocontrol says the program will provide a migration path to the newer media so that airframes using the ACARS version are not excluded from the services.

Once the first 100 aircraft are equipped, Eurocontrol plans to reduce route charges for CPDLC-capable aircraft in Link 2000+ airspace to encourage continued equipage, with a target of 25 percent of flights. Beyond that, the agency has drafted a rule that would make equipment mandatory: the agency has yet to finalize dates, but it envisions timeframes of 2009-10 for forward fit and 2012-14 for retrofit.

On the ground, CPDLC has been operational at the Maastricht UAC since June 2003. The Karlsruhe and Swiss UACs, along with the Canary Islands, Reims, Rome and Lisbon ACCs, are due to implement the technology in 2006-07, followed by the Madrid, Barcelona, Palma, Seville and Shannon ACCs in 2007.

The UK’s National Air Traffic Services (NATS), with input from Nav Canada, has drafted a requirements document for the service’s extension to the North Atlantic. Eurocontrol’s business case suggests that airlines would recover their investment in ATN/CPDLC in less than three years and ANSPs in less than seven.

One datalink already mandated is mode-S. “I think the mandates are clear and the industry is basically doing its best to provide the appropriate solutions so that the retrofits can take place on time,” Dias said. “It’s a major challenge for the industry because it involves equipping all individual aircraft, IFR first and then VFR.”

The mandate applies only in the core area, the airspace of Belgium, France, Luxembourg, the Netherlands and Switzerland, he said, “but almost all European aircraft fly in the core area and all long-haul aircraft fly there as well, so it’s a major challenge in terms of industry participation and activities. However, we are still determined to make it happen and make it a success.”

Mode-S, Dias said, represents a major change in the surveillance infrastructure, one that will be able to support the future traffic growth and future traffic demand. “It’s basically a technology change so that the systems can continue to accommodate more flights,” he said.

The transition period for the operational introduction of mode-S elementary surveillance ends on March 31 next year, for instrument flight rules and general air traffic (IFR/GAT) flights in defined airspace.

France, Germany and the UK are all moving to implement mode-S enhanced surveillance, which gives controllers access to aircraft-derived data, known as downlink aircraft parameters (DAPs). The eight parameters selected for initial implementation are magnetic heading, airspeed, selected altitude, vertical rate, track angle rate, roll angle, groundspeed and true track angle. Their availability is expected to help controllers increase their efficiency in tactically separating aircraft, enabling them to better assess separation situations while reducing their radio telephony workload and reducing the potential for communication errors.

Enhanced surveillance should also enable monitoring tools and safety nets that work on actual data, such as short-term conflict alert and minimum safe altitude warning, to be implemented or improved. Such tools in turn should help maintain or improve safety levels despite rising traffic levels. The provision of more precise predictions and monitoring of aircraft altitude changes and the execution of altitude clearances should also enhance safety.

Mandates for the carriage and operation of mode-S enhanced surveillance airborne equipment apply to all aircraft flying as IFR/GAT with effect from March 31 next year. There will be a two-year transition period to March 30, 2007, during which time a coordinated exemption policy will be applied.

To support the operational introduction of mode-S enhanced surveillance, Eurocontrol has formed a mode-S exemption coordination cell as a focal point
to manage declarations of compliance and requests for exemptions from the mandates by aircraft operators via a Web-based application.

Satellite Navigation
The European Union’s planned Galileo satellite navigation system appears to be back on track after two years that saw progress slowed by funding uncertainties, a dispute between Germany and Italy over leadership of the program, and protracted negotiations with the U.S. on security safeguards and the definition of signals that would ensure interoperability with the U.S. global positioning system (GPS).

The last was resolved in negotiations earlier this year after what Europeans characterize as years of hostility and obstruction on the part of the U.S. and formalized in June when the U.S. and EU signed the Agreement on the Promotion, Provision and Use of Galileo and GPS Satellite-Based Navigation Systems and Related Applications. The White House described the agreement as ensuring that Galileo’s signals will not harm U.S. and NATO navigation warfare capabilities, ensuring that both the U.S. and the European Union can address individual and mutual security concerns, and calling for non-discrimination and open markets in terms of trade in civil satellite navigation-related goods and services.

At the beginning of last month the two teams competing to operate the Galileo system submitted their bids to the Joint Undertaking set up in 2002 by the European Commission and European Space Agency (ESA) to oversee the program’s development phase.

On the industrial side, Galileo Industries was established in 2000 to develop and deliver the Galileo infrastructure as the industrial prime. Owners are Alcatel Space of France, Alenia Spazio of Italy, the German and UK components of EADS Astrium and Spanish consortium Galileo Sistemas y Servicios, with Thales expected to take a stake in the near future. France, Germany, Italy and the UK are each contributing $117.3 million (495.7 million) to help fund the development and validation phase of the program.

Air navigation is just one among many civil applications of both GPS and Galileo, but it is one that really needs the two constellations if its full potential is to be realized. Together, and with the help of local augmentation systems, they may even be capable of supporting Category II and III precision approaches.

Other applications include improved monitoring and surveillance as a result of aircraft being able to broadcast more accurate navigation data. And medical or rescue helicopters should be able to use the Galileo safety of life signal for missions in visibility where safe helicopter operations have so far been impossible.

In the meantime, the European geostationary overlay service (EGNOS) is about to become operational. A regional augmentation of GPS and Russia’s GLONASS consisting of transponders on three geostationary satellites and a network of ground stations, EGNOS is a counterpart to the U.S. wide area augmentation system and one that will generate a similar signal usable by the same receivers. The reliability and accuracy information carried by its signal enables users to determine their position to within about five meters.

Shorthand departure routes helping to reduce delays for business aviation

For the last two months, three airports in the New York metropolitan area have been participating in a trial program to find out whether business aircraft flight crews can use coded departure routes (CDRs) to reduce frequency congestion and decrease departure delays.

CDRs are a form of shorthand clearance issued as a way to expedite departures from busy airports, especially “on a thunder-stormy Friday night, when just about every aircraft is getting a reroute,” said Joanne Damato, manager of NBAA’s general aviation desk at the FAA’s ATC system command center (ATCSCC).

NBAA has been working with operators at Teterboro, N.J.; Morristown, N.J. and Westchester County, N.Y. airports, as well as flight plan service providers and FAA traffic flow management personnel to introduce CDRs to general aviation. The FAA has used the procedure for several years to expedite airline traffic.

“The time it takes to read a full route clearance can tie up the frequency for a minute or more,” Damato said. In such situations, controllers can instead issue a CDR to an aircraft if “CDR capable” is listed in the remarks section of the flight plan. To participate in the trial, crews must first review a PowerPoint presentation and a CDR procedures document, both of which are available on NBAA’s Web site.

If the trial is successful, NBAA intends to “push to make this a national procedure,” Damato said.

Noting “CDR capable” in the flight-plan remarks section replaces the need for individual operators to establish a Memorandum of Agreement with individual towers at airports where CDRs originate. “The goal for business aviation is to make this as automated as possible,” Damato said.

Tom White, traffic management officer at the FAA’s New York Tracon, said the only significant problem he is aware of thus far in the test program is that some crews have not had a current or complete list of CDRs available to them when they have been issued the clearance.

“We’re trying to find out if there are any logistical problems on the GA side,” he said. “For us in the New York area it’s going to be a very positive step to get the GA population on board.”

While the primary purpose of CDRs is to help aircraft avoid severe weather within 200 nm of a terminal area, White said that he expects ATC eventually to be able to issue CDRs for “volume relief” as well as during periods when severe weather avoidance procedures are in effect.

Robert Ocon, the CDR coordinator at New York Center, said the CDR concept originated “as an easy way for New York Center to amend routes,” not as a means of issuing abbreviated clearances to pilots. After years of using this system internally, controllers began issuing clearances to airliners using this shorthand.

Sometimes a CDR will match one of the Preferred Routes that are published in the Airport/Facilities Directory (for example, HPNALBPF, from Westchester County to Albany, N.Y.), but the CDR is not listed in the Airport/Facilities Directory as such. There are 581 CDRs originating in HPN to 108 destination airports, including five in Canada; 578 from TEB to 123 destination airports, including five in Canada; and 67 from MMU to nine destination airports in the U.S. Some CDRs incorporate jet routes while others use only low-altitude airways.

ARTCCs develop and maintain CDRs. Traffic managers can suggest adding new routes or deleting obsolete routes to the CDR coordinators at the other ARTCCs, who collectively decide whether to accept the changes. The coordinators try to limit the number of CDRs between individual city pairs to 10, but some routes that are especially prone to severe weather can include many more CDRs. For example, there are 23 CDRs for flights from New York Kennedy to Dallas Fort Worth.

The ATCSCC uses its “National Playbook” of scenarios to guide traffic around severe weather. “We try to tailor our CDRs to match their playbook,” Ocon said. It is impossible to write a CDR to cover every possible re-route scenario, and occasionally nature’s fury will tear even the best conceived severe weather avoidance plan to shreds. The FAA is using prototype software program known as the Post Operations Evaluation Tool (Poet) to track the use of CDRs by general aviation during the test period. Poet was developed by Metron, Cognitive Systems Engineering and ATM Systems Engineering under the FAA’s collaborative decision-making (CDM) program, as a way to identify inefficiencies in the daily operation of the National Airspace System. The ability to track CDR usage was added to the prototype system to support the New York test program, to see which routes are used most often.

As of press time, White said it was too early to decide whether the test is progressing as planned, or how many times controllers have actually issued CDRs to GA participants. A full report will be published at the completion of the test, he said.

The complete CDR database–which contains 15,400 routes between 363 airports in the U.S. and Canada–is updated every 56 days (concurrent with the chart cycle) and can be downloaded free from the FAA’s Web site at

Several flight plan service providers are offering CDRs to their general aviation customers as part of the New York-area test program.

Gary Gambarani, director of Arinc’s flight operations center, said that the company’s Arinc Direct flight planning system incorporates the complete up-to-date CDR database. If a user has notified Arinc that he is CDR capable, the user will have the option of calculating and storing several flight plans for the trip, including routes that would involve a CDR clearance.

“Once the avionics are fired up, users can recall the route over a datalink,” Gambarani said. “When we found out in May that this program was coming to fruition, within five weeks we had the [software] changes in test, and about
two weeks later it was ready. We knew the importance of the test program, and the urgency to get it out there during the summer months.”

Lisa Sasse, national account executive for Air Routing International, said the CDR database is compatible with the company’s Web-based Flight Manager tool. Universal Weather and Aviation will provide its customers only a printed copy of the appropriate CDRs with their flight plans, according to a company spokesman.