- TSA’s Quiet Skies program critiqued, again
- When will air travel recover?
- Where should drones be allowed to fly?
- Newark pioneers new model for rental car centers
- GPS backup finally getting closer
- News notes
- Quotable quotes
In 2018, the Boston Globe‘s Jana Winter revealed the existence of the Transportation Security Administration’s Quiet Skies program, under which federal air marshals (FAMs) are assigned to follow and observe specific individuals at airports who are not under investigation by any agency and are not in the government’s Terrorist Screening Database. Quiet Skies actually began in 2012, but it only came to light in 2018 when TSA re-assigned some of its FAMs to help staff the program. Several members of Congress subsequently asked the Department of Homeland Security’s Inspector General’s office to audit Quiet Skies and a redacted version of its report, “TSA Needs to Improve Management of the Quiet Skies Program,” was recently released on Nov. 25.
The redacted report reveals things about federal air marshal roles in the program that I was not aware of when I wrote about Quiet Skies in Issue 125 (Sept. 2018) of this newsletter. We now know that a passenger somehow identified as a candidate for FAM attention (despite not being in the government’s terrorist database and despite undergoing enhanced screening at the checkpoint) is not only followed and observed by FAM for “suspicious” behavior while awaiting his or her flight but is also followed onto the plane by three FAMs and again monitored for suspicious behavior during the flight. And in the two years (2018 and 2019) during which FAMs have been doing this, how many “hits” did they get? A table in Appendix G of the report shows that the FAMs noted “suspicious activity” in exactly three cases but that zero passengers were confirmed as aviation security threats. Alas, the table blacked out the number of individuals identified for enhanced Quiet Skies screening and the number actually surveilled by FAMs, so there is no way to calculate percentages.
The Inspector General auditors found that TSA did not develop outcome measures for the program—neither for the enhanced screening of Quiet Skies passengers nor for the value added by FAMs’ participation in Quiet Skies since 2018. The report also shows TSA did not always adhere to its own Quiet Skies guidance concerning privacy protection and it may not have removed some passengers from the Quiet Skies list after they met the criteria for being removed. There were even cases where some Quiet Skies passengers may not have received enhanced screenings at the checkpoint. The auditors reviewed 16 incident reports and found four in which the boarding passes did not include the required “SSSS” designation that alerts screeners of the need for secondary screening.
This is a dismaying report. In addition to raising questions about the value-added, if any, by Quiet Skies since its launch in 2012, the report comes up empty in justifying the use of federal air marshals to track and monitor people who don’t qualify to be on government watch lists or the no-fly list, especially the use of three FAMs taking up potential revenue-flier seats on airline flights to snoop on people who apparently pose no threat to aviation.
In light of the DHS Inspector General findings, I continue to believe that the creation of this program and the addition of FAMs to it were TSA’s reactions to two prior developments.
One was repeated studies by government and scientific organizations showing there was no evidence that TSA “behavior detection officers” played any meaningful role in aviation security. TSA nominally abolished behavior detection officers, but many were apparently redeployed as staffing for the newly created Quiet Skies started in 2012. And in the following years, as study after study questioned the value added by FAMs being deployed on selected commercial flights (when secure cockpit doors and a growing Federal Flight Deck Officer program were far-lower-cost means to the same end), TSA redeployed part of the federal air marshals workforce to Quiet Skies to give them another role and prevent the FAM Service from being eliminated from its budget.
With COVID-19 vaccinations starting to be distributed, many estimates are floating around about how fast air travel might resume over the next four years. Airlines, airports and air navigation service providers (ANSPs) all have a lot at stake on this question, but many estimates seem more like guesswork than analysis. For this article, I have turned to two reports based on at least some kind of analysis.
Bond-rating agencies have been busy revamping their models of airport finance, on which they base their estimates of those entities’ financial soundness. Fitch Ratings released its new assessment on Nov. 30, “Fitch Updates Its U.S. Transportation Sector Coronavirus Assumptions,” reviewing traffic trends at airports and toll roads. The latter has recovered much faster than airports and Fitch’s baseline case expects toll roads to average 100 percent of their 2019 traffic by the end of 2021.
For both modes, Fitch developed a ‘Coronavirus Severe Downside Case’ to compare with its ‘Coronavirus Rating Case.’ The former assumes no effective vaccine in use next year, while the latter was more optimistic—but the report was completed and released prior to any of the recent vaccine test announcements, so I am ignoring their severe downside numbers. Fitch’s base case predicts airport traffic reaching 65 percent of 2019 levels for the calendar year (CY) 2021, 80 percent for CY 2022, 90 percent for CY 2023, and 100 percent for 2024. I think those are plausible numbers given that it appears we will have at least three vaccines in distribution during 2021 and possibly several more.
But that is likely a better result for airports than it is for airlines. That’s because the most lucrative category of passenger travel—business travel—could be permanently reduced post-pandemic by between 19 and 36 percent. That projection was made by a four-person expert group convened by IdeaWorks and sponsored by Cartrawler. The experts were Ben Baldanza, the former CEO of Spirit Airlines, Charlie Leocha, president of the consumer group Travelers United, Scott McCartney, the “Middle Seat” columnist at The Wall Street Journal), and Jay Sorensen president of IdeaWorks.
Their methodology was to divide business travel into seven components, with data on the percentage in each category, and then to brainstorm (using whatever data they could find) on what fraction of that travel would no longer fly post-COVID-19 pandemic, making both high and low estimates for each.
For example, internal company trips (20 percent of business travel) were estimated to be reduced by 40 percent to 60 percent (thanks to Zoom and other technologies). By contrast, travel to conventions and trade shows (20 percent of the total) was estimated to be down by between 10 and 20 percent. And due to the personal involvement inherent in most sales call trips (25 percent of business travel), the estimated losses were between zero and 20 percent. Simple math led them to a low estimate that 19 percent of business travel could disappear and a high estimate that 36 percent of business travel could disappear.
If those numbers are anywhere near correct, legacy carriers are in for serious ongoing revenue losses, compared to pre-pandemic times. Business travel, especially international business travel, is the cash cow for legacy carriers. By contrast, low-cost carriers and ultra-low-cost carriers have much better prospects for recovering and perhaps exceeding their 2019 passenger volumes if or when vaccines are widely distributed and used since traveling for vacations and visiting friends and relatives is unlikely to be replaced by Zoom meetings.
Airports need to prepare themselves for reduced traffic from legacy carriers and increased service from low-cost carriers and ultra-low-cost carriers. This may accelerate the ongoing trend away from exclusive-use gates and toward common-use facilities at airports.
Earlier this month, Brent Skorup of the Mercatus Center released a thought-provoking working paper that urges a reimagining of near-surface airspace management (“Drone Technology, Airspace Design, and Aerial Law in States and Cities,” Dec. 2). The central idea is to replace the Federal Aviation Administration-governed (or presumed to be FAA-governed) near-surface airspace with a devolved property- and market-based alternative management framework. Under this approach, state and local governments, as well as private property owners, would have a say in where and when small unmanned aircraft systems (UAS) could operate, much like they do today with land under their control. Skorup’s legal analysis provides a convincing case against what is sometimes claimed as FAA’s near-absolute authority to regulate any air contrivance flying above the grass blades. However, the policy recommendations contained in the working paper raise a number of practical questions that Skorup should seek to address in future revisions.
Skorup begins with a survey of public law and court decisions related to airspace. While recognizing FAA’s general unitary authority over navigable airspace in the U.S., he convincingly argues that this authority is not boundless and likely leaves very low altitude airspace near the surface outside of absolute FAA authority. The Supreme Court has held that very low military and civil overflights can constitute a taking if those overflights substantially interfere with the property owner’s enjoyment of his property in cases involving dead chicken flocks (Causby, 1946) and sleepless nights (Griggs, 1962). Despite government attempts after Causby to expand the definition of navigable airspace to include airfield operations in an attempt to shield aircraft and airport operators from liability, Griggs held such operations can still invade private property. As a result, securing necessary avigation easements from private property owners has become a standard practice for airport operators nationwide in cases where it is not feasible to directly acquire land.
In addition, air rights are a well-developed concept regularly used in urban real estate transactions. All of this suggests that landowners have a property interest in the immediate airspace above their property. That being said, there is no bright line for determining when a near-surface airspace intrusion is presumed to be a trespass, with Skorup advocating for states to adopt a rule of 200 feet above ground level (AGL).
Skorup envisions a system of defined, defensible, and divestible property rights to govern near-surface airspace. State and local governments, as well as private property owners, could exercise those rights to exclude or allow small UAS to operate within their airspace parcels. As a starting point for future UAS network development, he encourages state and local governments to lease the airspace over their public rights-of-way to facilitate “drone highway” transit corridors that UAS operators such as package carriers could use.
Undoubtedly, this approach should have some basic appeal to free-market supporters as a substitute for highly centralized, command-and-control government airspace management. However, if the intent is to support the nascent UAS marketplace, this policy approach carries very serious risks that could hinder rather than help the emerging drone economy. In response to calls for airspace federalism and decentralization, longtime aviation lawyer Mark McKinnon noted earlier this year, “Ironically, many of the people arguing for more local control of airspace do so because they are afraid the FAA will become more and more heavy-handed and restrictive. A review of regulatory efforts, however, shows that when state and local governments act, it is almost always to ban conduct that is permissible under federal law.”
Indeed, one of the two primary supporters of drone airspace federalism in Congress, Sen. Dianne Feinstein (D-CA), has publicly complained for years that FAA’s airspace supremacy prevents her home state from imposing a variety of restrictions and prohibitions on UAS operations. Skorup’s intent is to foster UAS development and deployment, but those in government who share his near-surface airspace governance approach generally have the opposite intent. This likely explains why the entire UAS industry—with the notable exception of companies that develop and market unmanned traffic management systems—is strongly opposed to Sen. Feinstein and her colleague Sen. Mike Lee’s (R-UT) perennial legislative efforts to devolve low-altitude airspace authority to states. In future revisions, Skorup should explain how his idea to support UAS commercialization wouldn’t backfire and crush this infant industry, or at least how this risk can be mitigated.
Another similar concern relates to Skorup’s implicit assumption that small UAS will always be confined to transit corridors below the current Part 107 general limit of 400 feet AGL. Rather than being something intrinsic to the technology or commercial applications, this altitude limit reflects a compromise between FAA, traditional airspace users, and the UAS industry as a way to minimize conflicts with conventional aircraft while allowing for ongoing UAS research and early commercial deployments.
If drone federalism carries the day and UAS operators are potentially required to obtain authorization from thousands of entities, would the UAS industry seek access to higher altitudes to avoid this patchwork and flee back to uniform FAA control? Traditional airspace users would strongly oppose such a move, but if it was successful, state and local governments would lose revenue opportunity from near-surface airspace leasing while maintaining regulatory authority to prohibit drones from taking off and landing anywhere other than at FAA-certified airports.
Despite these significant unanswered questions, Skorup’s working paper presents a novel model of airspace management for a new type of aircraft. Readers should carefully consider these ideas.
At most U.S. airports, renting a car is a pain. The arriving passenger must wait on the curb for a rental-car bus, journey to the actual rental car lot, and then check out the car and depart. Airports would like to get those rental car buses out of the congested terminal roadways. They would also like to reclaim the huge acreage occupied by rental car lots, by shifting those operations into garages, ideally adjacent to the terminals themselves (as at Reagan National and a few other airports). But with the rise of alternatives to car rentals (Uber, Lyft, and future automated vehicles), how much risk should an airport take on to develop and operate a modern consolidated rental car center (ConRAC)?
A promising model is under development at Newark Liberty International Airport (EWR). The project consists of a six-story parking and rental-car facility plus an adjacent quick turnaround facility for washing and servicing incoming rental cars—and it is accessible from the terminal via an elevated walkway. Best of all, the EWR ConRAC shifts major risks from the airport operator (the Port Authority of New York & New Jersey) to the private developer/operator of the ConRAC.
The developer/operator is ConRAC Solutions, which is financing the $480 million EWR project with equity and debt. Its revenue stream will be a customer facilities charge (CFC) paid by each rental car customer. Over the 35-year lease of the long-term public-private partnership (P3), the CFC will increase by 2 percent a year. ConRAC Solutions and its equity providers and lenders will depend on this revenue stream for both debt service and their return on equity. They have no recourse to the Port Authority, which means the risks are transferred to the company.
The equity providers are Fengate Asset Management (owned by public pension funds) and Related Fund Management, an arm of real-estate developer Related Infrastructure. The initial debt is a 10-year bank loan, which can be replaced later on with longer-term financing such as revenue bonds. Fengate’s Mac Bell told Airport Business that although conventional municipal bonds that the PANYNJ could have issued would have had a lower cost of money, the PA would then have been responsible for risks such as construction cost overruns or future decreases in rental car use. For the PA these risk transfers offset the higher cost of capital, as is typical of this kind of revenue-risk P3 structure.
The EWR ConRAC is the first U.S. ConRAC to use a revenue-risk P3 model. The other public-private partnership ConRAC under construction today at Los Angeles International Airport (LAX) is financed based on annual availability payments made by LAX to the P3 company (Fengate and PCL Investments). Under that structure, key risks (including a future decline in rental car use) remain with the airport.
I think ConRAC Solutions has a winning model—and so does a leading infrastructure investment fund. Last month, the company announced a five-year partnership with iCON Infrastructure to develop other privately financed ConRACs at U.S. and Canadian airports, using the revenue-risk model.
There is a growing consensus in the United States and Europe that entire economies are overly dependent on GPS and analogous forms of global navigation satellite systems (GNSS). All forms of navigation (aviation, motor vehicle, maritime, etc.) depend on GNSS. GNSS precise timing signals underlie global telecommunications networks, banking transactions, electric transmission systems, and numerous other applications. It’s not just an aviation problem, and an aviation-only solution is a diversion from solving the overall problem.
In this country, the Department of Defense and Department of Transportation jointly developed the National Positioning, Navigation, and Timing (PNT) Architecture, which envisions multiple sources for these three vital functions. Last year, DOD went further, releasing its own PNT strategy document in August 2019. DOD envisions three layers: a global layer of GNSS, a regional layer based on terrestrial technologies such as eLoran, and a local layer using a variety of other technologies. The European Space Agency has developed a backup architecture for United Kingdom maritime commerce. The MarRINav report produced a hybrid approach using GNSS, eLoran, and short-range R-mode VDES.
In the National Timing Resilience and Security Act of 2018, Congress required DOT to test a variety of terrestrial precise-timing systems to back up GPS timing signals. Such systems were to be expandable to provide navigation services. As Bill Carey reported in Aviation Week (Nov. 9-22, 2020), DOT’s field tests of 11 such systems were carried out in March at two facilities—NASA Langley in Virginia and a Volpe National Transportation Systems Center facility in Massachusetts. Carey reports that as of late October, DOT’s analysis of the results had completed an interagency technical review, but there is not yet a projected release date for DOT’s report on the demonstrations.
Carey talked with people from some of the companies that took part, including two whose proposed systems are based on eLoran—UrsaNav and Hellen Systems. He summarized their proposed roll-out plans for PNT systems based on that technology, emphasizing the merits of a signal vastly stronger than that of GPS and in an entirely different part of the spectrum. Hellen Systems estimates that it could refurbish the 19 legacy Loran-C transmitter sites over a several-year period for $300-400 million, less than the cost of a single GPS III satellite. Their team includes L3Harris Technologies, which operates the Automatic Dependent Surveillance-Broadcast (ADS–B) ground network for FAA.
Carey’s article also notes that FAA’s current Navigation Roadmap remains increasingly dependent on GPS. For example, it is counting on the expanded use of GPS-based wide-area augmentation system (WAAS) for airport landing systems, refusing to invest in the latest generation of instrument landing systems (ILS) that are far more effective than legacy ILS. The same course is being followed in Europe via the expanded use of GNSS-dependent European Geostationary Navigation Overlay Service (EGNOS) for landing systems. (Note: I discussed FAA resistance to new-generation ILS in “A Rebirth for Instrument Landing Systems?” in the March 2020 issue of this newsletter.)
FAA continues to focus on an aviation-only approach to GPS backup, including a reversal of the original NextGen plan to phase out legacy VOR ground stations in order to retain a minimum operational network of about 600 by 2030. That plus an expanded network of distance measuring equipment (DME) ground stations will provide an emergency capability to enable aircraft to keep flying in the event of a serious GPS failure. Far better would be a robust multi-layer, economy-wide PNT capability, as called for by Congress and the National PNT Architecture. DOT should require FAA to get with that program, rather than continuing to focus on a crude aviation-only GPS backup.
Nav Canada Cutting Costs as Revenue Is Hit Hard
Though still hoping to be included in a government aviation assistance package, Nav Canada is coping with large losses in air traffic control user fee revenue this year due to 63 percent less air traffic than last year. It has had to make difficult decisions on operating costs. In September, the company announced layoffs of 720 people, about 14 percent of its total staff, none of which were air traffic controllers. On Nov. 24, it disclosed that it is considering reducing controller positions at seven control towers in lower-traffic locations, such as Whitehorse and Windsor. It is also considering converting the service at six other low-activity towers to flight service stations.
FAA to Use Space Data Integrator in 2021
FAA Administrator Steve Dickson told the NextGen Advisory Committee on Nov. 17 that the long-awaited Space Data Integrator (SDI) will go live early next year. With 56 commercial launches scheduled next year, SDI will use real-time telemetry data from launches and recoveries to minimize the extent of restricted airspace involved. The data will be fed directly to SDI at the FAA command center, where it will be displayed on an Enhanced Space Data Display updated once per second. FAA will also evaluate the use of space-based ADS-B data from Aireon to supplement the telemetry data with near real-time data from other air vehicles near the restricted airspace.
Denver Airport Releases Scaled-Back Great Hall Terminal Plan
A year after terminating a long-term public-private partnership to massively renovate and expand facilities in its landside Great Hall terminal, Denver International Airport unveiled a scaled-down $770 million renovation plan. It calls for a less-ambitious relocation and make-over of its two security screening checkpoint areas, adding only five more screening lanes. The two major carriers—Southwest and United—will still get enlarged check-in areas, but other airlines will not. And there will be fewer new retail establishments than in the original plan, which depended on concession revenue to provide debt service on the project’s revenue bonds. The renovation is to be completed by the end of 2021, two years later than originally planned.
NATS Selling Surplus Properties to Raise Cash
The public-private company that is the ANSP for the United Kingdom—NATS—is divesting six unused radar sites, as part of a drive to cut costs and increase revenue during the global depression in air travel. The company has 70 acres available for sale at the sites, as well as numerous other sites on which it is willing to lease the right to erect mobile phone masts and antennas. And on the cost-cutting front, NATS released 122 controller trainees, due to no prospects for their getting NATS jobs until 2022 at the earliest.
Broadband Satellite Provider Lands New Investor
OneWeb, a start-up company that declared bankruptcy earlier this year, has been restructured following two new investments totaling $1 billion—from Bharti Global (of India) and the UK government (which acquired a “golden share” as part of the deal). OneWeb will now resume its position as a competitor with global broadband satellite services being developed by Amazon and SpaceX. OneWeb plans to launch 34 to 36 satellites within the next month or so, with further launches through 2021 and 2022.
Two More Norwegian Airports Now Controlled from Remote Tower Center
Avinor, the ANSP of Norway, announced last month that its Remote Towers Center in Bodo is now controlling traffic at two more towers, at the Hasvik and Berlevag Airports. That brings the total to four. Avinor’s plan calls for 15 airports to be controlled from Bodo by the end of 2022. This is similar to the plan for the Scottish airports operated by Highlands and Islands Airports Ltd. That plan is being attacked by controllers and politicians as untried and risky.
Non-CO2 Climate Impacts of Aviation Highlighted by EASA
A new report from the European Union Aviation Safety Agency (EASA) confirms research reported in last month’s issue of this newsletter that non-CO2 emissions from aircraft (nitrogen oxides and contrails) are at least as important as CO2 emissions in terms of climate impact. The report identifies possible policy responses, including emission taxes, alternative fuels, and alternative altitudes to reduce the formation of contrails. Previous aviation measures in Europe focused solely on CO2 reduction.
Vinci Airports Testing Facial Recognition Technology
With 45 airports under its management, Vinci Airports is one of the world’s largest airport companies. It is launching a one-year trial at Lyon St. Exupery Airport of a facial-recognition system called Mona. Passengers can opt-in using the airport’s app. Once enrolled, the facial image is used at every step of the process, from check-in/baggage drop to security screening, lounge access, and boarding. The lure for passengers is an estimated total time saving of 30 minutes, thanks to dedicated lanes. Vinci says all data will be erased once the plane takes off. Initially, the full service will be offered on flights from Lyon to Porto and Lisbon, Portugal, with other destinations to be added next year.
$500 Million Cargo P3 Proposed at Anchorage International
IC Alaska Airport has proposed to develop, build, operate, and maintain a cargo facility of 360,000 square feet, with 14 aircraft hardstands. In exchange for the airport financing the project, the company would pay a lease rental rate of $0.18/sq. ft. for 55 years. The deal still needs to be negotiated in order to become a reality. The company involved was co-founded by the former chief investment officer of the Alaska Permanent Fund, Russell Read.
Sofia Airport P3 Agreement Signed
A consortium consisting of Meridiam, Munich Airport, and Strabag has signed a 35-year public-private partnership (P3) agreement with the Bulgarian Ministry of Transport to develop and modernize the country’s major airport. The consortium says it will bring global best practices and efficiency to Sofia Airport as part of the modernization.
House Transportation Leaders Seek Study of COVID-19 Transmission on Planes
Rep. Peter DeFazio (D-OR) and Rep. Rick Larsen (D-WA) have asked the Government Accountability Office (GAO) to study COVID-19 transmission on airliners to clarify what is and is not known about this subject. DeFazio chairs the House Transportation & Infrastructure Committee and Larsen chairs its Aviation Subcommittee.
Munich Closes Off Terminal 1 Due to Pandemic
As of Dec. 1, Munich Airport (MUN) put its Terminal 1 into “hibernation” due to the latest surge in COVID-19 cases and the airport expects it to stay closed until air travel resumes sometime next year. That means airlines, including Air France, British Airways, and Emirates, have been shifted to Terminal 2, where Lufthansa has long dominated. This relocation is much easier than it would be at most U.S. airports, thanks to the widespread European practice of common-use gates, which the airport can assign and reassign at it wishes. In November, MUN served only 10,000 passengers per day, compared with 120,000 per day in November 2019. Earlier this year, London Heathrow (LHR) closed Terminals 3 and 4, consolidating operations into T2 and T5.
“[T]he infrastructure backbone of the industry—airport and [air traffic management] procedures, slots, and so on—were constructed before the start of liberalization of the industry in the 1970s. They are completely airline-centric, not customer-centric. Even worse, the guidelines promulgated by ICAO demand that every airline is treated identically. The rule is ‘Peace, Love, Kerosene, Brown Rice.’ That may have been wonderful in the 1940s when airlines were state-owned and there was no competition, but those days are gone. Non-discriminatory, transparent, and priced according to the cost of production is a millstone that needs to be ditched immediately. Airports and ANSPs should be allowed to compete and to offer their customers differentially priced services, just like the airlines do. Now, when there is little traffic, is an ideal time to make changes that will benefit passengers as well as airlines.”
—Andrew Charlton, “Being the Reform We Need to See,” Aviation Intelligence Reporter, Sept. 2020
“The system with the biggest impact on mankind in the shortest period of time: that’s a great metaphor for what the Space Force does. Forty people, eight or ten on a shift, sitting in Colorado run the GPS system that is free to the world and that people around the world use incessantly. . . . And I would put forward GPS as the system that has had a bigger impact in a shorter time on all of mankind than any other invention in mankind’s time. I mean, think of fire, or the wheel, or the printing press—what would compete with the GPS system that has been fully operational just 25 years and is used by so many people around the world with so few people managing it?”
—Barbara Barrett, “The Space Force: A Conversation with U.S. Secretary of the Air Force Barbara Barrett,” Forbes.com, Nov. 13, 2020
“The Congressional Research Service recognizes that the FAA [Airport Improvement Program] entitlement formula prioritizes airport needs by a well-designed set of criteria. AIP, by act of Congress, is meant to serve the needs of a national air transportation system, not the needs of a congressional district’s aspiration to ‘build an airfield and they will come.’”
—Sandy Murdock, “Another Turkey from Congress? Hoyer and DeFazio Want Earmarks Back,” JDA Journal, Nov. 24, 2020
“We cannot have GPS signals be a single point of failure for transportation and other critical infrastructure sectors. More safety applications will depend on PNT [positioning, navigation, and timing] in the future. Public confidence in these will be critical. People will not be comfortable getting into an automated vehicle or with platooning driverless trucks heading down the highway if they think their invisible hand is not reliable or that their GPS might be spoofed. Getting public adoption of other PNT capabilities—space-based, terrestrial, and self-contained—integrated with GPS technology will be critical to the success of any such system.”
—Diana Furchtgott-Roth, Asst. Secretary for Research and Technology, U.S. DOT, in “No Silver Bullet for US PNT, Many Sources Needed,” GPS World, Aug. 18, 2020