Air Traffic Control Reform Newsletter #67
Photo 12987989 © Jakub Jirs?k -

Air Traffic Control Reform Newsletter

Air Traffic Control Reform Newsletter #67

Radar, the FAA and airlines, user fees

In this issue:

  • Wide-Area Multilateration Can Replace Radars
  • FAA and Airline “Customers”
  • Digital Communications Back on Track
  • ATC Revenue and User Fees
  • GPS Backup Still Lacking
  • News Notes
  • Quotable Quotes

Wide-Area Multilateration: Replacement for Secondary Radars

News stories last month announced a development in Colorado that is more important than non-aviation journalists realized. A wide-area multilateration (WAM) system went into full-scale operation in the mountainous area where four airports are located-Yampa Valley, Garfield County, Steamboat Springs, and Craig-Moffat County. Due to the mountainous terrain, there are serious gaps in radar coverage below 13,000 feet, which drastically reduced flight operations during reduced-visibility conditions. But with the new WAM system up and running, controllers at Denver Center can provide normal radar-like separations to planes flying in that airspace.

Multilateration refers to a kind of triangulation, based on measuring differences in the time of arrival of signals from a plane’s transponder to sensors at various known locations. It’s been used for years in airport surface surveillance systems like ASDE-X, both here and overseas. Wide-area MLat uses a larger array of ground-based sensors; in the case of the new Colorado system, there are 20 of them. They continually listen for signals from planes’ transponders and (if so equipped) their ADS-B equipment. A central unit computes the plane’s position and sends it to the appropriate ATC center, where it’s displayed on the controller’s screen just as if it had come from a traditional secondary surveillance radar (SSR).

But as Tony LoBrutto of Sensis Corporation (whose company produced the system installed in Colorado) notes, there are three important differences between SSR and MLat. First, MLat is significantly more accurate than SSR, primarily because its updates occur once per second rather than once every 6 to 12 seconds, and it is not subject to some of SSR’s inherent inaccuracies. Second, it is significantly less costly than SSR, both to acquire and to maintain. Third, MLat can handle ADS-B signals, which SSR cannot. Hence, it can provide a backup and integrity check for ADS-B.

Although the Colorado installation is the first WAM application in the United States (and will be expanded to areas served by seven additional airports), air navigation service providers in Austria, the Czech Republic, Fiji and South Africa are already well along on replacing SSR with WAM. Sensis and arch-rival Era Corp. (a subsidiary of SRA International) are involved in these and other MLat projects worldwide. The Czech Republic is one of the pioneers, with two Era WAM systems in operation and a third under contract. They will cover the country’s entire airspace, handling all en-route traffic from a single facility near Prague, when linked together in 2010. Since they are being certified to at least equal the capabilities of SSR, under Eurocontrol rules the air navigation service provider (ANS CR) can use the same aircraft spacings as with SSR (5 nm. en-route and 3 nm. terminal). ANS CR plans to phase out its SSRs over a period of 10-15 years.

Fiji is also under way with an Era WAM and ADS-B system for the entire Fiji Flight Information Region. It will replace the current air traffic management system for both en-route operations and at the control towers of Nadi and Nausori International Airports. If commissioned on schedule next year, this will make Fiji the first country whose entire system will be non-radar based but of advanced technology. South Africa in February commissioned Era WAM systems for terminal and en-route air traffic management within 60 naut.mi. of both Cape Town and Johannesburg airports.

If WAM is so much better than SSR, should air navigation service providers whose SSRs are wearing out buy new ones? Era’s Russell Hulstrom maintains they should not. In an article in Air Traffic Management last year, he suggested that shifting to WAM instead of SSRs will provide a smooth transition to an eventual ADS-B system, which he terms ADS-X (WAM plus ADS-B). Radars cannot track ADS-B equipped planes, but WAM can. And if the WAM system uses a clock timing system independent of GPS, it can also serve as a backup for ADS-B on an ongoing basis.

There has apparently been a fairly long-standing culture clash within FAA and other ANSPs between the “radar mafia” and advocates of MLat. It looks to me as if MLat is starting to win, and that bodes well for a safer and more affordable air navigation system.

FAA and Airline “Customers”

Responding to criticisms, from Congress and the media, that it has gotten too close to the airline industry, FAA Administrator Randy Babbitt in mid-September announced that the agency will no longer refer to the airlines as its “customers.” Instead, that term will be reserved for members of the flying public.

This change in terminology illustrates the schizophrenic nature of the FAA as presently constituted. In its identity as the nation’s aviation safety regulator, the decision is absolutely correct. The entities that are subject to its safety regulation are and should be at arm’s length from their regulators, and calling those regulatees “customers” sends the wrong message to the airlines, pilots, mechanics, flight schools, airports, and airframe and engine producers that it regulates, as well as to its own safety regulatory staff.

However, this change is exactly wrong for the agency’s largest branch, the Air Traffic Organization. The ATO is an “air navigation service provider” (ANSP), and as such, it has customers: those who operate aircraft in the airspace under its control. Creating the ATO early this decade was a big step forward for the FAA, clarifying roles and responsibilities by consolidating the agency’s air traffic operations and its “facilities and equipment” branch into a single, dare I say, corporate entity aimed at serving its customers.

Just about every other civilized modern western country has gone further, by organizationally separating its ANSP from its aviation safety regulator. The ANSP is typically made self-supporting via fees and charges paid by its customers, while the air safety regulator typically remains within the transport ministry, funded by general government tax revenues. This model has proven itself over the last decade in country after country, improving both air safety (by providing truly arm’s length safety regulation) and air traffic management (by depoliticizing the ANSP and making it more responsive to its customers).

Administrator Babbitt knows about this track record, having served on the advisory board of the best multi-country study of the before-and-after performance of 10 leading ANSPs, “Air Traffic Control Commercialization Policy: Has it Been Effective?” produced by MBS Ottawa and George Mason University, Syracuse University, and McGill University in 2005 and released in January 2006. ( I hope he will issue a clarification, explaining that this new policy does not apply to the ATO.

Digital Communications Back on Track

Way back in mid-2003, the FAA abruptly dropped a promising program called Controller-Pilot Data Link Communications (CPDLC), despite a successful trial run involving American Airlines in South Florida. Shifting routine air-ground communications from VHF voice radio to digital communications (text messages) was and is viewed as a key building block for NextGen, and the FAA decision to put the program on indefinite hold baffled many observers.

The good news is that digital communications is back, in both Europe and the USA. Still called CPDLC in Europe, it was officially mandated by the European Commission in January 2009, for EU air navigation service providers and aircraft flying above 28,500 feet within Europe. For Western Europe, the implementation deadline is February 2013 and for Eastern Europe, February 2015. The aim is to achieve at least 75% equipage in each region by the deadline dates, since most aircraft operators will want to operate at or above 28,500 ft.

The new EU regulation specifies that data link equipment must comply with ICAO standards for controller pilot data link communications. This will permit long-haul aircraft already equipped with FANS-1/A equipment to use its datalink function, while other aircraft may have to add new equipment compliant with ICAO-standard ATN/VDL communications.

The EU action may have inspired the RTCA Task Force that I wrote about last month to include Digital ATC-Aircraft Communications as one of its key near-term (“Now-Gen”) recommendations. Data link would be used for departure clearances, re-routes, and routine communications, with implementation beginning this year and proceeding through 2014. Like the EU plan, the RTCA recommendation calls for using already in-place FANS-1/A equipment on long-haul planes and ATN Baseline 1 equipment for other aircraft (including regional jets), which would have to equip by 2014. All Centers would be equipped by 2014, as would larger commercial airport towers. Since FAA does have a similar plan in the works (Segment 1 of its Data Comm program), Task Force members are hoping for timely FAA approval of this recommendation to expedite Segment 1. The RTCA report notes that “initial analysis by flight operator financial executives has shown a conservative ROI payback period of approximately 2.8 years.”

ATC Revenue and User Fees

The October 21 issue of Aviation Daily had two apparently unrelated articles on page 2. One was headlined “Yield Decline Worsens in September, ATA Says.” The other was captioned “House Lawmakers Caution White House Against User Fees.” Let me attempt to connect the dots here.

The first article reflects the latest data compiled by the Air Transport Association on month-by-month “yield” figures-airline revenue in cents per revenue passenger mile (RPM) from air service in four regions (Domestic, Atlantic, Latin America, and Pacific). Overall, yields were down 18% year-on-year, reflecting the 10th consecutive month of fare decreases. The graph on p. 7 of that same issue shows yields from January 2007 through September 2009. Domestic yield averaged about 13.6¢/RPM in January 2007, with a gradual uptrend peaking in summer 2008 at just over 16¢/RPM. Domestic yields have plunged since then to 13.3¢/RPM in September 2009.

This matters for ATC funding, because the single largest source of revenue for the Aviation Trust Fund is the 7.5% tax on airline tickets. Large declines in that source of revenue mean budget squeezes for the FAA overall, and especially for the ATO. The ATO budget is already under pressure due to the increased payroll costs that will occur thanks to the recent contract agreement with controllers’ union NATCA. Higher operating costs and lower revenue will mean budget cuts somewhere-and most likely in capital investment (i.e., modernization, also known as NextGen).

In recent years, the FAA itself (under Marion Blakey), the GAO, and the DOT Inspector General have all pointed out that a revenue system based on the price of airline tickets bears less and less relation to ATC costs as time goes on. The FAA, in particular, in its FY2007 budget proposal, laid out a sweeping funding reform, that would have ATC users pay for ATC services via user fees and the airport grant program via a user tax, with the federal general fund covering FAA safety regulatory activities. That proposal, alas, was dead on arrival in Congress.

Some of us cheered when we saw the Obama Administration’s initial budget projections, calling for a shift to largely user-fee funding for the FAA starting in FY 2011 (with an estimated $9.6 billion coming from that source). Needless to say, that has set off the usual anti-user-fee campaign among general aviation groups, primarily AOPA (representing mostly individual private pilots). As of this week, they have recruited 118 House members, from both parties, to sign onto their a letter to President Obama calling for the user fee plan to be dropped. The letter urges continuation of status-quo funding, ignoring how out-of-sync that funding is with the factors that drive ATC costs.

The last thing we need is another war between the airlines and business/general aviation over user fees. But we do need to put the ATO on a sustainable funding path, especially with the major capital investments it needs to make on NextGen, which will improve flying for everyone. That sustainable funding path almost certainly must involve the users of Centers and TRACONs paying for the services they get-but in a way that does not impose burdensome administrative costs or put small-plane owners out of business. Canada succeeded in threading this needle when it created the funding system for Nav Canada more than a decade ago. As the Administration works to flesh out its user fee proposal, it would be wise to use the Nav Canada model as a starting point.

GPS Backup Still Lacking

A very sobering article appears as the cover story of the October 2009 issue of Avionics: “Fixing GPs,” by Callan James. ( James summarizes the Government Accountability Office’s assessment, earlier this year, of the vulnerability of the GPS constellation to some of the existing satellites wearing out before enough replacements can be built and launched. ( But his principal focus is the congressional testimony last May by Prof. Brad Parkinson of Stanford University. Prior to entering academia, Col. Parkinson was the USAF’s chief architect of GPS and its original program manager, causing him to be widely known as the Father of GPS.

Parkinson outlined four possible approaches to mitigate (i.e., make less severe) a possible GPS “brownout,” due to fewer than necessary satellites being operational. One would be to reactivate five of the satellites that are currently shut down because their solar panels can no longer handle the power-hungry DOD nuclear detection functions-but could still provide civil navigation signals (though their remaining lifespan may be short). Another would be to accelerate the development of the next-generation GPS III satellites, which are far more powerful than the existing ones. But that would take money from other DOD programs, so is not very likely. A third alternative would be to launch some simplified versions of GPS III, sans the military nuclear detection functions-which the military is unlikely to favor. Last-and least good-would be to add more GPS IIF satellites to the current late and over-budget contract, which Parkinson himself said would “be both expensive and risky while not meeting [full] operational requirements.”

That, of course, leaves us with getting a back-up system in place, such as eLoran that I’ve written about in previous issues of this newsletter. It turns out that it was none other than Brad Parkinson who chaired the independent panel of experts (the Independent Assessment Team) that studied the problem for the Departments of Homeland Security and Transportation in 2007 and unanimously recommended eLoran as the best available backup for GPS. That recommendation was accepted by both agencies, and DHS announced in February 2008 that it would begin implementing eLoran as the GPS backup.

But then everything seemed to disappear into a black hole. The report disappeared from public view, and I’m told that the Office of Management & Budget continued its long-time effort to zero out funding for the Loran program-including eLoran. And language to that effect was included in the Obama Administration’s initial budget proposal. The report itself was only unearthed via a Freedom of Information Act request earlier this year, and several members of Congress took up the cause of reviving eLoran as the GPS backup.

The latest news is that the DHS appropriations bill approved by a House-Senate conference committee this month allows for termination of Loran-C signals on Jan. 4, 2010 if the Coast Guard (which operates Loran) certifies that the signal is not needed for navigation and if DHS certifies that it is not needed as the GPS backup. Let’s hope DHS gets this one right!

News Notes

Naverus Certified for Public-Use RNP Procedures
The company that pioneered development of precision approaches for airlines such as Alaska and Southwest, Naverus, received FAA certification last month to develop such approaches for public use at airports. Naverus has designed over 300 approaches that can be used by aircraft equipped for Required Navigation Performance (RNP)-in Canada, the United States, and other countries. Until now, public-use RNP procedures had been developed only by the FAA. The FAA’s decision to allow third-party developers should speed the introduction of such approaches.

CANSO Launches Middle East Region
The Civil Air Navigation Services Organization (CANSO) has launched a new region encompassing the Middle East, reflecting the growth of interest in upgrading ATC in that part of the world. CANSO held its first conference in the region in January 2009, in Jeddah, Saudi Arabia, and its board approved creation of the new region at its annual meeting in July. Thus far, two of the region’s Middle Eastern air navigation service providers are full members of the organization, GACA (Saudi Arabia) and NANSC (Egypt).

ATC Still on Inspector General’s Problem List
The DOT Office of Inspector General (OIG) produces a list each year of the DOT’s top management challenges-and once again, ATC modernization has made the list. Specifically, the OIG defined the problem as “moving toward the next generation air transportation system and improving the national airspace system’s performance.” The FAA’s second appearance on the list concerns air safety regulation: “strengthening aviation’s regulatory framework for safety and addressing human factors.” As I have written many times before, the strongest step DOT could take in this regard would be to separate the FAA’s air safety regulation organization from its ATC operation (the ATO), putting safety regulation truly at arm’s length from ATC operations, as is true for all other aspects of aviation.

JPDO Releases New Documents
Early this month, the Joint Planning & Development Office (the interagency group responsible for longer-term research and planning of NextGen) on Oct. 2, 2009 released several new reports, including a revised Integrated Work Plan, NextGen Enterprise Architecture, and enhancements to its Joint Planning Environment. Go to:

Belgium Ripping Off Air Travelers
One of the basic principles of commercialized air navigation service providers is financial autonomy-i.e., that the ANSP raises its own budget from the fees it charges for its services. But the government of Belgium is violating that principle when it comes to its allegedly commercialized ANSP, Belgocontrol. In each of the two latest fiscal years, the Belgian government has diverted €20 million from the ANSP to its own general government budget. The Association of European Airlines has rightly protested this ripoff, which is forcing airlines (and hence their passengers) to help cover the government’s budget deficit. This kind of thing calls into question the viability of the commercialization model under which the ANSP remains 100% government-owned.

Quotable Quotes

“The Czech strategy is to provide air traffic surveillance at least 20 naut. mi. beyond its own borders. It may be possible for Poland or Austria or another neighbor to make use of aircraft tracking data from [Czech provider] ANS CR when deciding whether or not to replace aging secondary surveillance radars in their own countries. The fact that multilateration makes it easy to share surveillance data means it’s a good tool to facilitate cross-border cooperation envisioned in the Single European Sky ATM Research (SESAR) modernization effort.”
–David Hughes, “An Alternative to Radar,” Aviation Week, October 20, 2008.

“I passionately believe that in 2020 no one will buy secondary surveillance radars. We will have crossed the threshold and our ANSPs and airspace designers will be able to improve safety, increase capacity, reduce fuel consumption, and decrease greenhouse gas emissions in ways that were never possible with secondary radar.”
–Russell Hulstrom, SRA Air Traffic Systems, “Why Buy SSR Any Longer?” Air Traffic Management, Issue 4 2008 (

“How likely and how serious is the threat of future GPS brownouts? As one senior industry official told Avionics, ‘If Brad Parkinson says there’s a threat, you’d better believe him, no matter what the DOD says.’ . . . Parkinson noted that ‘GPS is so much a part of today’s embedded infrastructure that brownouts must be avoided.’ But he cautioned that ‘To avoid this risk will require the best efforts of DOD, Congress, the GPS Program Office, the Air Force Space Command, and the contractors.'”
–Callan James, “Fixing GPS,” Avionics, October 2009.