In this issue:
- Obsolete FAA facilities and equipment
- Inspector General on FAA NextGen priorities
- Rethinking the broken ATC acquisition process
- The ATC “monopoly” red herring
- What private planes pay in Germany
- News Notes
- Quotable Quotes
The Hidden Problem of FAA’s Obsolete Facilities & Equipment
Last month, outgoing FAA Administrator Michael Huerta gave his last speech at the Aero Club of Washington. Among his most-quoted points was the following: “Structure alone cannot solve core funding challenges facing air traffic control. It’s time to have an honest conversation about what the American public expects us to do and how we are going to pay for it.” Which led to a response from one of my sources—a former FAA engineer—who emailed, “Imagine that! Michael Huerta wants a transparent discussion on FAA funding. He has neutered the budget by not being truthful about the state of the infrastructure for eight long years.” That may sound harsh, but please read on.
Earlier this year, a current FAA operations supervisor (who asked that I not disclose his name or facility) emailed me the following:
“At my facility, the radar scopes that are currently in use date back to 1974; the radar itself was commissioned in 1972. While we received some Y2K upgrades in 1999, in essence we are working air traffic the same way we did when ARTS II was commissioned around 1980. Our building will be 55 years old this year.”
Another source sent me a set of photos showing the badly corroded structure supporting an ASR-9 radar (the kind used at most airports with airline service). I queried him and he emailed back that there are about 140 ancient radars in poor condition that need to be replaced, but the best FAA can do is a minimally funded service life extension program (SLEP) just for the electronics, nothing for the antennas or pedestals. He also noted that the ASR in question was further damaged during Hurricane Irma and said there are no spare parts. And he added, “VORs are in even worse shape, and many buildings are falling apart.”
In searching for what FAA plans to do about aging and decrepit facilities and equipment, I managed to obtain an internal presentation, “Air Traffic Control Facilities and Engineering Services: Overall Facility Conditions,” Nov. 29, 2016. It identifies a 2016 portfolio backlog of $2.63 billion in infrastructure needs and $1.24 billion in safety and environmental compliance needs. The largest item in the infrastructure needs is $1.4 billion to replace aging power systems, and the largest item in the latter group is $1.03 billion in environmental cleanup. Note that there is nothing in this backlog for replacing ancient radars and VORs, or consolidating facilities (such as the 21 en-route centers) that have mostly reached the end of their useful lives, despite large sums spent during the ERAM upgrade to fix leaking roofs, poor elevators, and electric power.
By contrast, the next page lists what was to be available in FY 2017 to spend on reducing the listed backlog: $292 million for infrastructure and $159 million for safety & environment. Why so little? The heading gives it away: this is the “FY17 President’s Budget” for this line item. It is what the FAA Administrator was allowed to ask for after a give-and-take with DOT Secretary Anthony Foxx. In other words, the head of the FAA cannot go to Congress and honestly say: “We have a $3.9 billion backlog of facility & equipment needs and it needs to be funded.” All he can do is present the budget that the Office of Management & Budget has approved for submittal to Congress.
It gets worse as you turn the pages. The presentation goes on to explain the kind of triage FAA has to go through to decide the most urgent bits and pieces it can address with these dribs and drabs of funding. And that’s why the idea, from early this decade, of a major facility replacement and consolidation effort, has been lost down the memory hole. Of course, in addition to lack of funding, there is the inevitable pressure from Members of Congress to prevent losses of jobs in their district (which helped kill the plan from earlier this decade to consolidate New York Center and New York TRACON).
The rest of the presentation goes on to discuss conditions at staffed facilities: en-route centers, TRACONs, and towers. FAA uses a quantitative measure called the facility condition index (FCI). Any score below 90 is considered “poor condition.” By this measure, the centers are in relatively good shape, though their average FCI has declined from 94.6 in 2009 to 93.9 in 2015. Average FCI at core terminal facilities declined at 100 out of 137, and declined at 188 of 264 other terminal facilities (towers and TRACONs).
But the really disturbing figures are for the 45 TRACONs and towers whose FCIs are in the “poor” range. Some of these are relatively small facilities, such as the towers at Duluth, Key West, and Long Beach. But seven of these are major TRACONS, including those of New York, Denver, Central Florida, and Southern California. And poor-condition towers include Anchorage, Baltimore, Charleston (SC), Jacksonville (FL), New York Kennedy, and Oklahoma City.
Fixing these kinds of problem would be an obvious priority for the new ATC Corporation. After working out a sensible plan for replacing many centers and TRACONs with new consolidated facilities, and making use of remote tower technology to consolidate smaller towers, the entire n-year effort could be financed via revenue bonds, with debt service payments coming from the stream of ATC user fee revenues. The status quo offers no way to address this large and growing problem.
(For one example of a plan to consolidate TRACONs and Centers, see the following Reason Foundation policy study from 2013, by Michael Harrison, et al.: https://reason.org/files/air_traffic_control_facility_consolidation.pdf)
Inspector General Dings FAA on NextGen Priorities
In its first report on air traffic control in FY 2018, the DOT Office of Inspector General (OIG) reviews FAA’s progress in implementing the four near-term NextGen priorities it agreed to focus on at the recommendation of the NextGen Advisory Committee (NAC), which consists of a broad array of aviation stakeholders. Despite the innocuous title (“FAA Has Made Progress Implementing NextGen Priorities, but Additional Actions Are Needed to Improve Risk Management”), Report # AV2018001 turns out to be a very serious critique.
Rendered into plain language, the report’s most important findings are these:
- The way FAA reports milestones is misleading, overstating the program’s success;
- The benefits from some of what’s been implemented thus far are minimal; and,
- FAA is not adequately identifying risks up-front, and this is leading to delays in implementation.
On the surface, things look pretty good for these four priority areas (multiple runway operations, performance-based navigation, surface operations, and DataComm). For the three fiscal years 2015 through 2017, FAA reports having implemented 93% of its planned 147 milestones (p. 6). But when you get deeper into the OIG report, a much different picture emerges. The audit finds that FAA’s definition of “implemented milestones” includes cases where a new capability was installed but is not in operation—e.g., prototype electronic flight strips in the new control towers at San Francisco and Las Vegas (which won’t actually be used until 2021) and the runway-incursion system ASSC at SFO (which was installed in 2014 but did not become operational until October 2016). So OIG concludes that “Milestone completion reports overstate FAA’s success.” (p. 17)
Second, FAA does not know whether benefits are actually being achieved at some locations where implementation is completed and the new capabilities are in operation. For example, Wake RECAT has been implemented at LaGuardia and Chicago Midway. But at Midway, the benefits are actually negative (i.e., arrival delays are worse, not better) and only minimal benefits are expected at LaGuardia, due to most of the aircraft being in the same size category. MITRE Corporation’s report on the Northern California Metrroplex found that fuel savings were negative in the months after new performance-based navigation (PBN) procedures were implemented. And the Atlanta Metroplex’s PBN procedures have been partially suspended “to mitigate safety issues.”
This leads to OIG’s third major critique—that FAA has not effectively assessed risks in advance of going forward with implementation. Thus, when problems emerge that might have been foreseen and countered as part of the implementation process, the result is delays that play havoc with actually achieving various milestones. OIG cites the escalating battles in Metroplex locales over community objections to more-concentrated noise under the PBN flight paths. FAA “could have anticipated the high risk due to the heightened public interest at other airports” as a threat to PBN’s long-term success. For the surface operations priority, a key element was a new system called ASSC that helps controllers detect ground vehicles on the airport surface. Despite concerns at SFO about limited controller visibility, which could be addressed via surface movement radar, FAA “implemented” ASSC there in 2014 without that additional radar, leading to actual use of the system being delayed more than a year.
OIG concludes the report by stating that in order to accomplish what it promised the NAC stakeholders by 2020, FAA must proactively mitigate several complex risks, yet it has “not developed a detailed mitigation plan to address identified risks, involved industry in its decision-making process, or transparently [i.e., honestly] reported its progress in this area.”
Rethinking the Acquisition Process
By Sid Koslow
Editor’s note: Sid Koslow was Nav Canada’s vice president of engineering and then vice president and chief technology officer for most of its first 20 years, after several decades at MITRE Corporation. He received the Air Traffic Control Association’s Glen A. Gilbert Memorial Award in 2015. A longer and slightly different version of this article appears in the Fall 2017 issue of The Journal of Air Traffic Control.
The acquisition of air traffic systems has proven to be difficult in practice—especially for systems with increased functionality. There have been few successes—if success is defined as the on-time, within-budget delivery of expected functionality.
A standard process has been used by ANSPs for more than 40 years, with a remarkable lack of success. The standard acquisition process includes program justification, detailed requirements definition, contractual arrangements, building, testing, and installation. Despite its troubled track record, this remains the standard practice for nearly all ANSPs. It’s time to examine the problem and determine whether the standard acquisition solution fits.
Air traffic management (ATM) systems are based on complex sets of rules with myriad exceptions built up over years of experience, including the special needs of individual airspaces. The rules are not scientifically based, in that there are no formulas, and the rule set can never be complete. Envisioning a new system with new functionality in complete detail is not possible.
The objective of ATM capability acquisition is to provide useful new functionality for the operation. The inherent nature of the activity is development, since the precise operation of the system in the many varied circumstances in which it needs to work cannot be known in advance.
It does not matter how experienced or how thoughtful those involved may be, or how much time they spend writing requirements. Requirements written before development are always wrong, at least in detail.
Development is the only way to be successful, which means learning the way forward to a result that is not altogether predictable, at least in its detail, and detail is everything for an ATM development to be successful.
Yet we continue to apply the standard procurement approach. The standard approach is linear and does not take into account the uncertainty inherent in the problem or the fundamental need to iterate, as the system capabilities come into view. However, the problem does not care about our solution. The problem forces learning and iteration on us in the form of change requests. No matter how competitive the original contract was, change requests are sole-source. There is no other way to get to get a useful system.
The fatal flaw of the standard procurement approach is the false premise that the requirements are known. They may be envisioned to a degree, but they are not known initially, at least not in detail. The result is an attempt to conduct development in a contractual strait jacket. This situation is exacerbated by the promise of a large, game-changing capability needed to get the project approved. In fact, this front-end promise—typically much more than can reasonably be delivered—sets up the project for greater and often unnecessary complexity in the design and development phase, as well as increased difficulty, an elongated time horizon, and substantial cost increases through the implementation.
This is in no way an indictment of the people or organizations involved in the acquisition. They typically work hard to make the procurement a success. However, unless a system is acquired that is already in use and accepted as is, the standard procurement approach is unfit for the purpose of acquiring ATM capability.
Given the above points, we must ask: What is a suitable approach to ATM development?
An effective alternative involves continuous collaboration between experienced ATM operational personnel on the one hand, and ATM development personnel on the other—working together. What is the basis of collaboration and progress if a detailed requirements specification is not produced as in the standard procurement model?
The intermediate term (five years nominally) capability needs to be established. Then a base capability needed to get to the intermediate capability is established, along with people, schedule and cost implications, taking into account inherent uncertainties.
Some preliminary design work will need to have been done in order to have reliable estimates. Succeeding steps will be based upon the base capability. The steps are incremental with no big leaps. Close collaboration between Operations and Engineering is absolutely essential to set expectations on which resources are based. Success is unlikely without mutually understood expectations and appropriately derived resources.
It is extremely difficult to recover from a bad start. All the processes in the world will not help if the system and software design is not solid or if the scope is not aligned with the resources. In engineering, it is said that quality cannot be “tested in.” In other words, the early work is crucial, and complete recovery will not happen without extreme difficulty if underlying issues are discovered late in the project. The value of a well-prepared project start cannot be overstated.
Written requirements are an attempt at an explicit definition of imagined notions of future system capability operating in an extremely complicated and variable environment. Software is developed that implements the developer’s interpretation of the written requirements in the standard approach. There is an inherent lack of common language between the requirements people and the developers. A prototype is the answer.
Developers are pleased to build prototypes because they can do something creative early in the process rather than analyze paper. As well, operations people are pleased to react to them, because they are real, and they act as a common language. They also allow exposure and visualization by a wider range of people throughout the organization, such as requirements providers, including those from head office, as well as the all-important field personnel who will help transition the capability into operation.
A prototype is the vehicle that enables the reduction of uncertainty, allowing the development to converge on a successful outcome. In order to avoid time delays between successful prototypes and fielding operational systems, prototypes should be built on versions of existing operational software.
But what about those who believe that they need to be in control? Experience shows that the standard approach often leads to large schedule slippages and very large cost overruns. What kind of control is that?
Besides, the people who must be trusted in the collaboration approach are the very same people who in the standard approach are trusted to determine requirements, determine which change proposals are essential, and determine when the capability can go operational. Why not trust them in an approach which is more likely to succeed?
The bottom line is that the standard procurement approach is unlikely to lead to success, while the collaborative approach is likely to lead to success.
The ATC “Monopoly” Red Herring
Opponents of ATC reform have recently come up with yet another argument against the bipartisan proposal that would remove the Air Traffic Organization from FAA and convert it into a federally chartered non-profit corporation, funded by fees for its services like any other utility. AOPA President Mark Baker in the September issue of AOPA Pilot wrote that “Privatization [sic] in this case is a euphemism for monopolization,” and that the ATC corporation would “face no competition.” Well, duh, if the ATO is now operating as a monopoly, changing its funding and governance cannot be “monopolization,” which means to make something become a monopoly.
Jumping on this bandwagon was the American Conservative Union Foundation, which in October released its (written for the occasion) Seven Principles of Privatization. These would be fine if ATC were a competitive business (like British Airways was when it was privatized by Margaret Thatcher’s government). ACUF argues that the ATC system should be put up for competitive bidding (sale to the highest bidder) and operated as a for-profit monopoly with no regulation of its rates. This ignores:
- That no U.S. aviation stakeholders support a for-profit ATC company;
- That the company bidding highest would seek to recover the amount it spent to buy the ATO via higher rates and charges; and,
- That ATC as we know it today is and will be a monopoly, and therefore requires some way of having its customers protected from monopoly exploitation.
Let’s be clear about the monopoly nature of air traffic control. To be sure, control towers can be and are being provided by competing bidders—in this country via the Contract Tower Program and increasingly in Europe, as noted in previous issues of this newsletter. But no workable model exists—either in theory or practice—for competing ATC providers in the same airspace. Perhaps that day will come someday via currently non-existent technology, but for the foreseeable future, we will be dealing with ATC as a de-facto monopoly.
There are three known ways to deal with the potential of monopoly pricing and exploitation of customers, and all three are well represented among U.S. utilities. They are:
- A government corporation, which is presumed to be acting in the public interest and not exploiting its customers. We observe this model in municipal electric, gas, and water utilities.
- An investor-owned, for-profit company with a legal monopoly, whose charges and usually also its profit (rate of return) are regulated by a public utility commission.
- A user co-op, of which there are thousands, such as rural electricity, water, and telephone co-ops. Aviation co-ops are also prevalent; examples include the original ARINC, today’s SITA, and various airline co-ops at airports, such as LAXFuel.
In ATC today, since the global wave of corporatization began in 1987, we see mostly government corporations, but these are far more like real businesses than most of what we term government corporations in this country (Amtrak, U.S. Postal Service, etc.). There is one for-profit, partially investor-owned ANSP—the U.K.’s NATS, 49% owned by the government, 5% by its employees, and the balance owned by airlines and pension funds. NATS is price-regulated as are the privatized U.K. airport, electricity and water utilities.
There is only one private, non-profit ATC corporation—Nav Canada. Its rates are largely unregulated, because its board members are nominated by aviation stakeholders, in keeping with the user co-op model. They have an interest in the rates being affordable, and having any “profits” used either for capital modernization or to reduce future rates. This is the model that the large majority of U.S. aviation stakeholders have chosen as the best fit for this de-facto monopoly, and Nav Canada’s superb 20-year track record is hard to beat. Among the ANSPs of advanced developed countries, it has the highest productivity, as measured by indicators such as IFR flight hours per controller hour or IFR flight hours per dollar spent. Despite the self-regulatory nature of a nonprofit co-op structure, legislators built in an appeal process for both Nav Canada and the proposed U.S. ATC corporation; in both cases the appeal is to the federal transportation agency.
Finally, just a reminder why advocates of corporatization don’t call it “privatization.” It’s not privatization. It is intended as the transformation of the existing ATO into a more-effective funding and governance model, which is feasible only if it is removed entirely from the federal government and its budget process.
What Private Planes Pay in Germany
One argument AOPA uses to frighten private pilots is the specter of ruinously expensive fees to fly within the country’s controlled airspace. In this newsletter I have repeatedly explained that small private planes in Canada do not pay any per-transaction fees to its ATC corporation, Nav Canada. Instead, they pay a modest annual charge based on the plane’s weight (which for most recreational piston planes is C$68/year). Moreover, the current House FAA bill, which includes the ATC corporation provision, specifically exempts all general aviation aircraft from any ATC fees or charges. (Those planes would presumably continue to pay aviation fuel taxes, which would continue to support the federal airport grants program, AIP.)
But these facts have not stopped AOPA from running periodic articles about the horrors of flying a small plane in Europe, Latin America, Australia, or New Zealand. One example is a column by Tom Haines, editor in chief of AOPA Pilot‘s November 2016 issue. In it he recounts examples of private pilots in France, Germany, the U.K., and New Zealand paying an assortment of airport and ATC fees.
I’m not about to defend the taxes and charges levied in any of these countries on GA aircraft. The political fact is that the United States and Canada have much larger GA communities than elsewhere, and they have become skilled at gaining political influence. Governments everywhere tend to impose taxes and fees on those with little political influence.
That said, I was intrigued by the comments on GA charges made by the CEO of Germany’s well-respected ANSP, Deutsche Flugsicherung (DFS), at the ATCA Annual conference in October. My notes related him saying that VFR flights by GA planes in Germany are not charged, and that the German government reimburses DFS for its costs of serving non-paying customers. But I wasn’t sure I was scribbling notes accurately as I tried to keep up with Klaus-Dieter Scheurle’s remarks at that session.
After reviewing my notes, I emailed Scheurle a set of questions, seeking to clarify the situation. Here is my summary of his responses. VFR flights are generally not charged for, even in en-route airspace. When GA flights go IFR, they are exempt from normal ATC fees if they have a maximum take-off weight less than two metric tons. In those cases, the German government reimburses DFS for the fees it would have collected, had those flights not been exempted. By the way, GA is defined in Germany as all civil flights that are neither scheduled nor charters.
There is one exception to the general rule set forth above. DFS charges all aircraft terminal charges for departures in the airspace near all 16 of Germany’s international airports. In addition, most international airports in Europe are capacity-constrained and seek to manage demand via defined landing slots and/or landing fees. What airports charge is up to the airport operators, and is not determined by DFS. However, the airports use this revenue to cover the cost of providing tower services at these major airports.
Returning to the debate over U.S. ATC corporatization, you might wonder why no one has proposed that the federal government reimburse the US ATC corporation for services provided at no charge to GA aircraft. The consensus among the working groups that developed the basic framework for the ATC corporation plan—at Business Roundtable and the Eno Center for Transportation—was based on advice from Nav Canada’s then-CEO not to go down that road. Why? Because any federal tax money that goes into the ATC corporation would open the door to congressional “oversight” and attempts to micromanage the new ANSP. And that, in the view of most proponents, would defeat one of the key aims of corporatization—to de-politicize air traffic control.
New Video Explains Space-Based ADS-B Over the North Atlantic. Air traffic control is complex, and often difficult to explain to non-experts unfamiliar with the field’s acronyms and jargon. In a well-done 4-minute video, Nav Canada graphically explains how air traffic is managed over the oceans today—and how greatly improved it will be once space-based ADS-B surveillance becomes available in late 2018. An enjoyable eye-opener for your non-aviation friends or your favorite Member of Congress. (https://www.youtube.com/watch?v=hib6k7GNOks&sns=em)
NATS Brings Electronic Strips to Belfast Control Towers. As of mid-October, the NATS-operated control towers at Belfast International and Belfast City airports are equipped with electronic flight strips, replacing paper. But in addition, the data driving the strips resides on a central server at the NATS Swanwick Control Center. NATS refers to this as its Hub and Spoke system for tower data, and plans to extend the concept to other airports with NATS-operated towers, including Bristol, Southampton, Farnborough, Cardiff, and London City.
IAA and Isavia Expand Free Route Airspace in North Atlantic. Since 2009, the Irish Aviation Authority has offered Free Route Airspace (FRA) in the high-altitude Shanwick Oceanic airspace. In October, IAA expanded this into Shannon’s lower airspace, down to 7,500 ft. This expansion is part of a collaboration among nine northern European ANSPs to provide FRA across their entire areas of operation. The Borealis Alliance comprises the ANSPs of Denmark, Finland, Norway, Sweden, Iceland, Ireland, the U.K., Estonia, and Latvia. In parallel, Iceland’s Isavia added new entry and exit points to the Reykjavik FIR, in cooperation with adjacent ANSPs. Once the Borealis FRA program is completed, fuel burn within that airspace is projected to be reduced by 46,000 tonnes per year.
ENAIRE Upgrades Controller Work Stations. The ANSP of Spain—ENAIRE—has announced plans to upgrade controller work stations in its en-route and terminal facilities, to replace paper flight strips with electronics, a change which has already been implemented at ENAIRE control towers. The new equipment is a product of a collaborative effort among seven ANSPs and technology company Indra, called iTEC, aimed at delivering interoperable work stations and later Common Flight Plan Processing. Besides Spain, the other member ANSPs are from Germany, Lithuania, the Netherlands. Norway, Poland, and the U.K.
London City Airport Signs 10-Year NATS Contract. After losing two control tower contracts to the towers division of DFS in recent years, NATS has been upping its game in its U.K. home market. Last month it signed a 10-year contract to continue its relationship with London City Airport, where it has been the control tower operator since the airport opened in 1987. NATS and London City are collaborating to install the U.K.’s first remote tower at London City, which will be operated out of the NATS control center at Swanwick.
NBAA Loses Key Member Company. Long-time NBAA member General Electric stunned the business aviation community by announcing the sale of all but one of its business jets and shutting down its New York-based flight department, which was a founding member of NBAA, in 1947. The move came just a few weeks before the NBAA’s annual convention in Las Vegas.
“Some argue that we need to keep the current structure in place and invest more in it. Unfortunately, that’s the equivalent of throwing good money after bad. Congress is already several billion dollars behind in getting systems for which they appropriated taxpayer money. I’ve witnessed the professionalism and dedication of our FAA employees and controllers firsthand. This is not an indictment of them. The problem is the inert procurement and financing structure that hinders modernization efforts. . . . The proper solution is credited to President Clinton, who proposed in 1993 establishing an independent, nonprofit entity to run air traffic control. The idea now has the support of the current administration, House Speaker Paul Ryan, forward-thinking Democrats, and the unions representing air traffic controllers and pilots.”
—David Grizzle, former COO of the FAA Air Traffic Organization, “No Time to Delay at U.S. Airports,” Boston Herald, Sept. 16, 2017
“Recently we’ve taken a fresh look at the air traffic control reform designed to improve the efficiency of air travel. Based on this review, as well as our own experiences with commercial airlines, we strongly support the long-overdue modernization of our air traffic control system. . . . For decades, government agencies have done the best they can with an unstable and unpredictable funding structure. But we have to face the facts: if we want to succeed in modernizing our ATC system, we need a new approach that will help attract and sustain the long-term investments that this major undertaking will require. Simply put, the system’s current governance and funding structures cannot deliver the 21st century technology needed for more-efficient, customer-focused air travel. Given the essential and immediate need for relief, I ask that you re-examine your position on this issue, or at least make clear that you do not speak on our behalf.”
—Chuck Jones, CEO, FirstEnergy (NBAA member for 10 years), letter to NBAA President Ed Bolen, May 15, 2017
“The proposal, which has been under consideration by various administrations for decades, would move air traffic control out of the federal bureaucracy and move it into a federally chartered, not-for-profit corporation. With members representing a wide variety of consumers and system users, the reform would allow for significant improvements, while keeping safety oversight under control of the FAA. These proposed reforms would allow the new ATC system to modernize through less bureaucratic red tape, new bond-financing tools, and greater long-term funding certainty. All of which would allow for greater investments in new, satellite-based technologies and help bring U.S. aviation into the 21st century.”
—Former Sen. Kit Bond (R, MO), “New Flight Plan Will Take U.S. Travelers Safely into Future,” St. Louis Today, Sept. 13, 2017
“NextGen would be developed and deployed in a different way for many reasons if it was executed under a corporatized ATC structure. The ability to raise capital from the private sector will be translated into execution clarity, expedited decision-making based on true return on investment. The interaction with the corporation’s board will drive decisions and the clarity of mission. The bottom line will be driven by the customer—people who fly in the airspace—experience. The ability to prune the NextGen program tree will be accelerated, freeing up resources to focus on key priorities and continuously improving the service offering.”
—Vincent Capezzuto, Chief Technology Officer, Aireon Corporation, “U.S. Insights Survey,” Air Traffic Management, Quarter 3, Fall 2017