The Hidden Cost in the Lack of ATC Safety Regulation

By Langhorne Bond, Former FAA administrator

(ASW note: the following commentary is an abbreviated and updated version of a presentation given Feb. 5 at the North American Aviation Safety Conference hosted by the Flight Safety Foundation in Atlanta, Ga.)

Problem

The Federal Aviation Administration (FAA) has no formal, structured safety regulation system for air traffic control (ATC), unlike virtually all developed countries and the European Commission.

This absence has allowed bureaucratic empires and programs to emerge [the cost of which] is estimated at $4 billion without a useful role yet certified.

Disclaimer

Let me begin by spreading the blame. Like most program disasters, the WAAS/LAAS (wide area augmentation system/local area augmentation system) tangle is a result of many mis- steps, some almost 20 years old. The present management of FAA is not culpable and instead has the uphill task of straightening it all out.

The fact is that making a GPS (global positioning system) signal safe for aviation precision approach is an immensely difficult task, requiring much more time and money than originally, optimistically predicted.

It is doubtful that these systems will have much, if any, benefit to those who are paying for them - aviation users.

Easy to declare with the benefit of hindsight, some may say. I maintain that it was all foreseeable.

Sponsorship

Back in the late 1970s and mid-1980s there was a pervasive belief that the FAA's R&D (research and development) shop was launching a bunch of expensive, fascinating projects, which ultimately fizzled because they didn't produce any real-world benefits. The MLS (microwave landing system), a technical success, was cited as an example.

So the practice of "sponsorship" began. An operating office of FAA - airports, safety, and air traffic - would endorse and adopt a development project because it would benefit its area of responsibility. In the absence of any recognizable long range planning, sponsorship is as good an oversight system as any. But it is out of control with respect to GPS augmentation.

The romance of satellites

By the early 1990s it was evident that the Department of Defense (DoD) GPS program would have enormous potential for all sorts of civilian applications. The GPS satellites broadcast two positioning signals: an encrypted P code for military users (providing sufficient accuracy for weapons targeting) and an open C code meant for civil users to provide position and timing information.

DoD realized from the outset that the civil signal was (a) very accurate and (b) available to hostile military forces and terrorists. The civil code could be used as a targeting system against the United States and its allies. So the GPS birds incorporated "selective availability" (SA), which made the civil signal inaccurate for precise targeting and for many civil uses, including precision approach for aviation.

As civil uses of GPS multiplied, DoD was pressured to turn off SA. President Bill Clinton's 1996 decision directive decreed that SA would not be turned off until 2006. As it turned out, SA was turned off in 2000 - six years early.

The civil GPS signal opened new and exciting possibilities in navigation guidance. A culture arose in the FAA that GPS would revolutionize and modernize ATC. It would render obsolete the existing array of ground-based navigation and surveillance system - ILS (instrument landing system), VOR (VHF omnidirectional radio range), DME (distance measuring equipment), NDB (non-directional radio beacon), LORAN (long range navigation), and even radar used by controllers.

Expensive GPS-based programs were launched that would replace the ground-based systems, which would be scrapped, saving lots of money for the U.S. government. Aircraft operators would discard their multiple avionics boxes and would replace them with a small number of boxes based on a single signal - GPS. They, too, would save lots of money.

A new role for the safety office

Instrument approach is one of the most important elements of the ATC system. The ground-based transmitter providing this service enables aircraft to approach and land safety in bad weather. There are two generic types: non-precision and precision approaches.

Non-precision approach (NPA) provides an accurate track over the ground but it does not provide a stabilized, straight-line descent - continuous vertical guidance - to the runway threshold. NPAs are found at small, lightly used airports where the expense of a precision approach ILS is not justified. The accident rates of NPA-equipped airports are higher than at ILS equipped airports.

Precision approaches provide continuous vertical guidance - a straight line through the clouds - as well as a direct tack over the ground as the aircraft descends. Precision approaches are of immense economic value because they permit scheduled operation in bad weather. In the hands of skilled pilots, they also are very safe. There are now 1,100 ILS- equipped runways at the 700 busiest U.S. airports.

So, as the list of GPS-services was developed, it became necessary to parcel out the new projects to an appropriate sponsoring office in the FAA. Instrument approach by GPS presented a problem. It was an integral part of the ATC system, so perhaps the air traffic services (ATS) office should be the sponsor. On the other hand, instrument approach clearly had a safety dimension, so perhaps the FAA's office of regulation and certification (code AVR) should be the sponsor.

The selection decision was influenced by the air traffic office's lack of enthusiasm for GPS precision approach. The air traffic folks could see no reason to discard a nationwide - indeed worldwide - array of ILSs which were increasingly cheap, increasingly reliable, very safe, and in place.

So the safety office, AVR, was selected to sponsor WAAS and LAAS, the GPS-based replacements for ILS. This fateful decision led to a new role for AVR: spokesperson, advocate, supervisor, designer of cost-benefit studies, and co-ordinator of meetings of a new bureaucratic entity - the SOIT (satellite operations implementation team).

Improving the GPS signal

GPS, modified by SA, lacked the accuracy and integrity to guide an airplane safety to 200-ft. above the runway in a Category I approach. Something had to be done to modify the basic GPS signal to meet these stringent standards. The answer lay in augmentation systems.

WAAS transmitted corrective signals from geostationary satellites over the equator. Because WAAS messages are limited as to accuracy and integrity, WAAS would provide for Cat. I approaches everywhere.

LAAS, the "local" area augmentation system, would be installed on a specific airport and would provide Cat. II and III approaches, where needed.

The birth of GPS 'sole means'

The Office of Management and Budget (OMB), noting that the GPS systems would be duplicative of the ground-based equipment, insisted that the ground-based equipment be turned off and removed. This would offset the cost of GPS systems.

Thus began the government's embrace of the principle of GPS "sole means" - that GPS would be the only navigation system in the cockpit and the only service provided by the government (see ASW, July 23, 2001, 'GPS Virus'). It is the FAA's duty to decide what is safe and what is not. The FAA failed to state to OMB that GPS sole means was not safe and that most of the ground-based navaids had to be retained.

Emergence of the SOIT

To promote U.S. GPS programs domestically and abroad, the SOIT was formed, nominally, within the safety office, AVR. The SOIT is co-chaired by the person from the flight standards office and from the certification office, both within AVR. The SOIT was established as sort of a special program office (SPO) outside the typical bureaucratic hierarchy. Central to the SOIT's self-generating "theology" is the principle that GPS sole means is safe - GPS needs no backup. When questioned on this point, the SOIT leaders responded that the question was not in their charter.

Unfortunately, that question is in no one else's charter at the FAA.

Neither the SOIT, nor the names of its chairmen, are in the FAA phone book.

ATC safety regulation

The proper solution to the ATC safety vacuum is simple: the function should be independent of ATC operations (just as it is independent of air carrier operations and airplane manufacturing) and it should be in AVR.

This solution is correct whether ATC remains as is, or even if a non-profit organization along the NAV CANADA model is set up. The AVR safety office doesn't want to touch it.

Augmentation as the offspring of sole means

Both WAAS (for Cat. I) and LAAS (for Cat. II & III approaches) depended on the doctrine of GPS sole means. If the ILSs were retained, WAAS and LAAS would be duplicative and unnecessary.

The doctrine of sole means was the subject of constant criticism from outside experts and institutions - all characterized sole means as deeply flawed and unsafe. The FAA fought back to protect its programs.

The death of sole means

The end finally came Aug. 29, 2001, with publication of the GPS Vulnerability Assessment by the John. A. Volpe National Transportation Systems Center. It was read in full by Transportation Secretary Norman Mineta, who endorsed its findings.

There is no turning back.

The report also is highly critical of some of the FAA's professional officers and of its past leadership.

The situation today

The requirement to carry a secure, backup ground-based positioning source to complement GPS is not that hard to achieve, nor does it impeach potentially useful GPS roles, such as ADS-B (automatic dependent surveillance - broadcast), which are planned for oceanic, domestic en route, and terminal flight.

But the need for the augmentations, WAAS and LAAS, is largely eliminated. The continuation of the ILS transmitters and the continued use of ILS receivers on aircraft means that the 1,000 busiest runways in the United States will not use a GPS approach aid. Nor will the ILS-equipped runways in the rest of the world. One thing is clear: if the FAA had done its safety work from the first, neither WAAS nor LAAS would have been undertaken. With a total program cost estimated at nearly $3 billion, its remaining aviation roles are minor. Small airports without an ILS precision approach may now have a glide slope added to their NPA. It is hard to envision a market for WAAS among air carriers, who have said that all along. There are many WAAS users today, but not in aviation, and the number is increasing. Agricultural users owe a debt of thanks to the FAA for paying for WAAS with taxes on air carriers.

The situation with LAAS is more optimistic. The program is in its infancy and can be stopped. LAAS is a very short-range replacement for ILS at busy airports, which will now keep their array of ILSs. There are no benefits to small airports or to general aviation.

Now searching a role for LAAS, the FAA is proposing that it can be used to fly high accuracy tracks and curved final approached. This is true but unpersuasive. Flight management systems with basic GPS can fly any high accuracy track and intercept an ILS glideslope. Most air carriers have figured this out and will not equip with LAAS.

The next steps

It is now evident that much of the FAA's furious and expensive GPS augmentation development would have added little to ATC capacity even if GPS sole means were a viable concept, which it is not.

However, basic unaugmented GPS is a superb, high accuracy positioning signal in space, especially now that SA has been turned off.

The real revolution comes from computerized, modern avionics. Improvements in ATC capacity and safety will come from avionics advances and in airspace redesign. Fortunately, this work is proceeding.

Meanwhile, four steps should be taken to set a better path for the future:

1. Establish an ATC safety regulatory office in AVR, whether they like it or not.

2. Continue WAAS development. It can't be stopped now. Maybe the Department of Agriculture will chip in.

3. Kill LAAS. In the words of a skeptical OMB director in the Nixon Administration, "Now you guys have done it. You've created a program with no benefits at all."

4. Stop AVR from "sponsoring" projects. Abolish the SOIT. The research shop (FAA code ARA) and the air traffic office (FAA code ATS) are perfectly capable of implementing ATC technology and have done so since 1938.

Byline: Langhorne Bond was FAA administrator from 1977-1981. He has authored numerous papers examining the safety, system architecture and cost benefits of GPS and other elements of the future air navigation system. In recognition of his lifelong contribution to ATC, Bond received the 1999 Glen A. Gilbert Memorial Award from the Air Traffic Control Association. (The Volpe Center report on GPS vulnerability as a sole means system may be viewed at http://www.navcen.uscg.gov/archive/2001/Oct/FinalReport-v4.6.pdf)

Pitfalls of Air Traffic Control Privatization

By Prof. Elliott Sclar, Columbia University, February 2003 (extracts)

Cost cutting related to privatization has been directly or indirectly blamed for two recent transportation accidents:

• A July 2002 midair collision above Switzerland killed 71 people, including 52 Russian school children. Investigation indicated system problems at Skyguide, the company that operates the Swiss air traffic control system, including inadequate staffing, a degraded communications link with German controllers, a collision alarm that had been taken out of service for maintenance, and a general lack of clarity about lines of responsibility and authority.
• In May 2002, the 'Potters Barn' train derailment in London killed six people and seriously injured 65 more. Poor maintenance and slipshod inspections by Railtrack, the privatized rail infrastructure operator, are likely to blame.

Privatizing ATC has been 'just short of disastrous' in countries that have tried it. Specifically:

• In Britain, the newly privatized National Air Traffic System has been forced to go to the government for financial bailouts, valued to date at two-thirds of the system's original sale price. In addition, technology failures have resulted in multiple system shutdowns and operational irregularities.
• In Australia, excessive demands on controllers have led to a series of strikes, while failures of new technology have led to actual radar blackouts and major traffic disruptions.
• In Canada, the privatized system has led to massive increases in user fees and dangerous understaffing in towers.

Source: NATCA. For the report on the pitfalls of privatizing ATC, see http://www.natca.org/assets/Documents/mediacenter/PDFPitfallsofATCPrivatization.pdf.

A Major Management Challenge

Project: Wide Area Augmentation System (WAAS), designed to provide satellite-based navigation for airspace users. Estimated cost: original, $892 million. Estimated current: $2.9 billion. Projected deployment schedule: original start 1998. Current start, 2003; finish, to be determined.

Integrity concerns have plagued WAAS development. While the agency has made progress in resolving these concerns, FAA must decide whether to stop WAAS development in 2003 or continue to refine the technology to provide an approach capability with greater precision.

Source: GAO, Major Management Challenges and Program Risks, January 2003 (Report No. GAO-03-108), p. 26 (See http://www.gao.gov/atext/d03108.txt)