Tetra Tech Expands its Aviation Technology Solutions with the Acquisition of BridgeNet International

Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK) announced today that it has acquired Bridgenet International Inc. (BridgeNet). BridgeNet is an aviation technology solutions firm based in Newport Beach, California, that is focused on aerospace data analytics, environmental and acoustic consulting, and 3-dimensional airspace visualization for federal and commercial aviation customers.

BridgeNet develops, sells, and supports its proprietary software, Volans, a web-based 3-dimensional application designed to create, evaluate and display flight operations. This tool enables engineers and aviation experts to simulate and display potential acoustic and environmental impacts from new performance-based navigation procedures and flight operations, as well as runway and airfield configurations. Volans is being used throughout the world, including in the United States, Canada, Australia, France and England.

“New performance-based navigation systems require more advanced assessment and management tools,” said Dan Batrack, Tetra Tech’s Chairman and CEO. “By combining the expertise of Tetra Tech and BridgeNet, we have expanded our ability to provide technologically differentiated solutions for life-cycle aviation services from airspace and ground support to environmental and aviation demand modeling and forecasting worldwide.”

Paul Dunholter, BridgeNet’s President, stated, “This transaction represents an exciting new chapter in our business. Tetra Tech shares our commitment to advancing the science of performance-based navigation. This is an extraordinary opportunity for us to join a technology-focused firm with the global resources to broaden our ability to support aviation and airports around the world.”


About BridgeNet (www.airportnetwork.com)

BridgeNet develops and deploys innovative management and technology solutions that address complex aircraft noise and airspace issues for airports and air traffic organizations.


About Tetra Tech

Tetra Tech is a leading, global provider of consulting and engineering services. We are differentiated by Leading with Science® to provide innovative technical solutions to our clients. We support global commercial and government clients focused on water, environment, infrastructure, resource management, energy, and international development. With more than 16,000 associates worldwide, Tetra Tech provides clear solutions to complex problems. For more information about Tetra Tech, please visit tetratech.com, follow us on Twitter (@TetraTech), or like us on Facebook.



Jim Wu, Investor Relations
Charlie MacPherson, Media & Public Relations
(626) 470-2844
Any statements made in this release that are not based on historical fact are forward-looking statements. Any forward-looking statements made in this release represent management’s best judgment as to what may occur in the future. However, Tetra Tech’s actual outcome and results are not guaranteed and are subject to certain risks, uncertainties and assumptions (“Future Factors”), and may differ materially from what is expressed. For a description of Future Factors that could cause actual results to differ materially from such forward-looking statements, see the discussion under the section “Risk Factors” included in the Company’s Form 10-K and 10-Q filings with the Securities and Exchange Commission.

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Part 5: How do Aircraft Navigate?


In the last edition, we spoke about the problem with many existing noise abatement procedures that they are not integrated into flight procedures that govern how aircraft will arrive to and depart from an airport. In this installment, we will outline how aircraft navigate along flight paths. NOTE: As this blog series is focused on establishing a baseline knowledge level for further discussions about current concerns for airports and communities, this will focus on air carrier and business jet aviation. This will not focus on general aviation such as small private aircraft.


Flight procedures, paths that aircraft fly through the sky from airport to airport, are provided to most pilots through two means: 1) paper charts, and 2) digitally in their aircraft navigation systems. These aircraft navigation systems are an onboard computer, outlined in the red circles in Figure 1, that contain a database from which the pilot selects an Air Traffic Control (ATC) assigned path. This onboard computer, known as a Flight Management System (FMS) then sends navigation commands to the aircraft’s navigation displays. Additionally, the FMS receives inputs from GPS satellites to assist in the location and navigation along the flight procedure.

Figure 1. Flight Management Computer (FMS) sends flight commands to the aircraft’s
navigation displays to assist the pilot fling the Flight Procedure assigned by ATC.


When the pilot is preparing the aircraft for flight, they will enter the ATC provided flight procedures into the FMS. They will then confirm the FMS displays on the navigation screens in front of the pilots. Once satisfied that the flight displays are programmed correctly per the ATC clearance, they will proceed to the runway for takeoff. An important point to make here is that the FMS only displays the flight procedure from the database within its memory. It does not have an ability to show other FYI items that might be of concern to local communities such as noise monitors, areas to avoid, houses, etc. The FMS only displays the ATC cleared flight path for the pilots to reference.


In the next blog, we will identify the takeoff profile of an aircraft using the FMS programmed flight procedures. This is a more complicated procedure that it appears on the surface and has implications on community expectations surrounding the airport.


About the Author:

Grady Boyce is a current and active Captain for a major airline flying the B-737. He has participated in, and led, airspace developments and ATC modernization efforts on all continentsexcept Antarctica. Grady is a consultant to BridgeNet bringing flight procedure development, ATC expertise, and TERPS assistance into their current and future activities.

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Part 4: The Problem with Noise Abatement Procedures - Integration


In the last few articles, I have outlined some of the basics of Flight Procedure and Airspace Design. In this post, I want to take a small digression and discuss Noise Abatement Procedures and THE fundamental problem with them as designed today: They are not integrated into the National Airspace System (NAS).

A vast majority of airports with noise abatement procedures (I would venture to say 98-99+%) do not mesh with existing aircraft flight procedures. Flight Procedures are very specific paths that aircraft fly. These are built by the FAA in conjunction with a number of stakeholders through a process that this blog series is shedding light on. Noise Abatement procedures are often developed by an airport or local community. These are not the same thing. (NOTE: the discussion here assumes a larger airport with business jets and/or commercial airline traffic. It does not assume small local airports solely served by General Aviation.)


Flight Procedures
Business Jets and commercial aircraft, when cleared for takeoff, are cleared on a very prescribed pattern that has been developed by the FAA in conjunction with Air Traffic Control and other stakeholders. These publications are free to the public for viewing and can be obtained here: https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/dtpp/search/

In our previous blog on “Airspace and Flight Procedure Development: Part 2 What is a Flight Procedure?” we provided insight and definition into procedures. We will not repeat that blog post here, but will simply say that Flight Procedures are how business jets and commercial aviation aircraft get to and from the ends of a runway at the airports they serve.


Noise Abatement Procedures
Communities around airports are becoming more involved in local flight activities at the airports near their homes. In an effort to mitigate impacts from increased aircraft activity at an airport, they work with local airport authorities to design their desires as to how an aircraft should fly when departing. For example: Fly heading 300 degrees until passing the industrial park, then fly on course.


Integration: Flight Procedures and Noise Abatement Procedures

Figure 1 shows an example procedure of a FAA designed flight path from a runway end. When an aircraft is cleared to depart these runways, they either fly a heading of 258 degrees or 078 degrees based on the current wind direction. What the aircraft has been given is an Air Traffic Control clearance and the pilots must comply with that clearance.

Figure 1. Departure Flight Procedure (Source: FAA)


Now, assume there is a noise abatement procedure at the airport as described above to fly a 300-degree heading until over the industrial park. The aircraft is not going to fly that procedure. They are going to fly their Air Traffic provided clearance.


The Problem & The Cure

The pilots cannot fly the noise abatement procedure as written for the following reasons: 1) Their ATC clearance mandates a 258-degree heading (assuming a west bound departure), 2) The departure procedure makes no mention of the noise abatement procedure, and 3) there is no way for the pilots to know where the industrial park is. Therefore, the fundamental problem becomes: There is no integration between the FAA developed flight procedures and the desired noise abatement procedure.

The solution is for all stakeholders to work together and develop a flight procedure that both works for Air Traffic Control and for the local community. Only then, will these two needs merge.


Going Forward…

Airspace procedure development and the merger of noise abatement procedures is a complex task. The above provides a high-level overview of the issues. In our upcoming posts, we will continue to detail how all of this works, how procedures are designed, how aircraft navigate, and so on. At BridgeNet we work hard with local communities and the FAA to help bridge an understanding. This is accomplished through our outreach product, VOLANS (email us to see a demonstration), and our NextGen and Airspace experts.


About the Author:

Grady Boyce is a current and active Captain for a major airline flying the B-737. He has participated in, and led, airspace developments and ATC modernization efforts on all continents except Antarctica. Grady is a consultant to BridgeNet bringing flight procedure development, ATC expertise, and TERPS assistance into their current and future activities.


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BridgeNet and Cesium Showcase Partnership: Software for Powerful Visualization




Newport Beach, CA – November 2, 2017  – BridgeNet International and CESIUM Consortium, two world-class companies, have established a showcase partnership enabling effective visualization and communication through unparalleled 3-D maps. BridgeNet, through their award-winning VOLANS software, will leverage CESIUM enabled visualization in their consulting and software development services for clients such as the FAA, San Francisco International Airport, NavCanada, London-Heathrow, and other communities, airports, and regulators around the world.

BridgeNet International, whose core services are related to noise studies, analysis and reporting of aircraft operations near airports, flight procedure visualization, analysis and development, and the visualization of flight and noise data, relies on the capabilities of its proprietary VOLANS software suite. The dedication of CESIUM to the best possible performance, precision, visual quality, and platform support to their software products enables BridgeNet’s robust offering.


“BridgeNet is proud to partner with a top-tier company of the caliber as CESIUM. Our showcase partnership is a dedication to the professionalism of both entities,” said Paul Dunholter, President.




About BridgeNet International

BridgeNet International invents and deploys innovative management and technology solutions that address complex noise and airspace issues for airports and residential communities. With more than two decades of experience and original software solutions, the company identifies problems precisely and solves them through a diagnostic process that mitigates political, community and technical concerns, and builds consensus for ideas and solutions. BridgeNet International is headquartered in Newport Beach, CA and has offices in San Diego, CA and Georgetown, TX. For more information, visit www.airportnetwork.com.


About Cesium
Cesium is an open-source JavaScript library for world-class 3D globes and maps. Our mission is to create the leading 3D globe and map for static and time-dynamic content, with the best possible performance, precision, visual quality, platform support, community, and ease of use.For more information, visit www.cesiumjs.org




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Part 3: What is a Flight Procedure?


So far, we have defined the difference between RNAV and conventional flight procedures and what airspace is. This installment in the series will discuss what a Flight Procedure is. Later installments will merge these concepts as we continue to explore airspace and flight procedure development as a whole for an airport and its surrounding communities.


A Flight Procedure, the topic of this blog, is a lateral path through the air that moves from point to point and connects airports. In some cases, flight procedures can have a vertical element to them as well, however, for the purpose of this discussion we will only be concerned with the lateral path.


The lateral path is tantamount to the freeway system that you use every day when going to work. When you leave your home, you drive onto an on-ramp to become established on the freeway. In aviation, this on-ramp is tantamount to a Standard Instrument Departure (SID) that connects the departure airport, or your home, to the freeway, or in aviation, the aviation “enroute” system. Think of the freeway as a series of straight paths defined by a “waypoint” at each turn or change of direction. For example, when the freeway turns to the right, imagine there is a fixed point there that ends that straight segment and begins the next straight segment. Figure 1, outlines this concept using a flight procedure from the FAA for the John Wayne Airport (KSNA). Once on the freeway you follow that path until it is time to get off.


When nearing your destination, you must exit the freeway to arrive. In aviation, this is called a Standard Terminal Arrival Route (STAR). These three paths, SID, enroute, and STAR comprise most of what we know as flight procedures. The last basic category, which will be covered in a later post, are arrival procedures, or instrument approaches.


Historically, flight procedures, such as the one outlined in Figure 1 above, were defined and developed by air traffic control facilities through coordination between airspace sectors (for definition of airspace sectors, see the last blog posted). These procedures were either based on ground based navigation aids or RNAV paths (the difference between the two was covered in an earlier blog). During the last 10+ years, the development of these procedures has grown to a more collaborative process where airspace stakeholders, such as air carriers, air traffic control, military, and FAA  headquarters representatives convene to amend, add, or delete flight procedures to the air traffic system.


Although this collaboration has expanded over the years, typically, airport authorities and/or airport representatives have not been a part of this process. This was not a snub to them, but instead a by-product of where the airports fell in the overall flight path. For example, most flight procedure modifications address activities beyond a 5-mile radius from an airport since within this radius the paths to and from a runway are less apt to be modified. However, these paths too can be changed, and that will be the topic of another post in this series.  Therefore, airports have not been a part of the flight procedure and airspace modification process. Recent FAA flight procedure implementations have prompted airports to seek some involvement. At BridgeNet, we work with airports and their communities to help address concerns and provide an understanding how all of these elements merge to impact noise and other environmental effects.



About the Author: Grady Boyce is a current and active Captain for a major airline flying the B-737. He has participated in, and led, airspace developments and ATC modernization efforts on all continents except Antarctica. Grady is a consultant to BridgeNet bringing flight procedure development, ATC expertise, and TERPS assistance into their current and future activities.


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Part 2: What is Airspace?

In this next installment of Airspace and Flight Procedure Development, we’ll focus on
defining: What is Airspace. This is important to address this topic before we delve into a
historical view of airspace and flight developments and before we discuss how these are
addressed today.

Have you ever looked above you and thought: What a beautiful, clear sky? I think we
have all done this where we admire cloud formations, geographic features, endless lakes
and oceans, and other features surrounding us. From an aviation perspective, wide open
expanses are often how the airspace above our heads is considered, however, the reality is
significantly different.

Prior to 1946, there was a common law which stated a person whom owns a plot of land,
also owns the sky above it. Enter Mr. Causby, owner of a chicken farm in a field next to
where the military placed a new airfield. The aircraft on approach to the runways were
literally scaring his chickens to death, causing Mr. Causby great financial harm. Citing
the common law, he filed suit against the government claiming ownership of the air
above him. The government countered citing the 1926 Air Commerce Act. Seeking a
final remedy, the United States Supreme Court handed down a landmark ruling favoring
the Commerce Act and ending this ownership of the airspace above a property owner.
This ruling gave rise to the Civil Aeronautics Authority (CAA) which eventually became
the Federal Aviation Administration (FAA).

As air commerce has grown the ability to manage the traffic within has become more and
more complex. Thus, the FAA has divided the airspace into “sectors” that assist Air
Traffic Control (ATC) in the management of this traffic. These sectors are defined by
lateral and vertical boundaries. For example, a sector may extend for 20 miles
horizontally and vertically for 10,000’ with other sectors surrounding it on all sides as
well as above and below. Figure 1 below is an overview of the Los Angeles Class B
airspace (NOTE: The FAA designates “classes” of airspace based on their overall usage.
The discussion here about sectors is independent of the classes of airspace. We are not
addressing classes of airspace here.) This diagram shows a top down view of the overall
airspace lateral boundaries. Within each boundary there are altitude limits drawn that
look like 100/50. This means that parcel of airspace, within those lateral boundaries,
extends from 10,000’ to 5,000’ above the ground. Below, above, and adjacent to those
altitudes are other sectors of airspace.

Figure 1. Los Angeles Class B Airspace Overview. A full image can be found here: https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/vfr_class_b/media/Los_Angeles_Class_B.pdf

This stratification of airspace exists all over the world with certain locations being more sectorized than others based on traffic flow. Air traffic patterns/flows, can change over time through a modification process that involves negotiations between the sectors impacted by the desired change. Reasons for a sector boundary change may include safety reasons, traffic flow, new flight procedures, or other such occurrences.  When a change needs to be made to an existing sector, the Air Traffic Control (ATC) group that controls that sector will approach the adjacent ATC sector and begin a process of working out how changes can be made and assessing what the impact will be to the overall structure beyond these two sectors in discussion. This process is not instantaneous and must proceed through a well-documented FAA process before a final amendment can be made. This last point is very important to consider when someone looks at a map and says: Why don’t we just move the flight pattern over to this new location?  Airspace is not that simple.

Finally, if the image above seems confusing, that is because it is. Now, go back outside, take a look up at the sky above you and picture this stratification. Sectors of airspace surround you and are closely monitored by ATC and the FAA. Changes can occur, but must address many surrounding issues and stakeholders, such as airports, airlines and the surrounding community to name a few, in the process. As we continue this series, this process will be central to our discussions.

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Part 1: The difference between Conventional and RNAV Flight Procedures.

With airspace and flight procedure development in the forefront of the news these
days, we are going to begin a new series that discusses how airspace and flight
procedures are developed. In this series, we will discuss the following topics:

  • The difference between conventional and RNAV procedures
  • What is Metroplex and its origin
  • How airspace and flight procedures were designed in the past
  • How airspace and flight procedures are designed today
  • What processes and rules are used in these developments
  • How do aircraft fly paths in the sky
  • How to merge a local community’s concern with successful flight procedure development



As this new series of is kicked off, it is beneficial to define the “credibility”, if you will, of the author. I am currently a Captain of the B-737 for a major airline and during my tenure at the airline, I spent 9 years in charge of their airspace and flight procedure development programs. Additionally, I am an FAA approved flight procedure designer, have been an FAA flight examiner, have consulted to the FAA and International Civil Aviation Organization (ICAO) on flight procedures and consulted to governments and companies such as Honeywell and Boeing. These series will pull from that experience and attempt to demystify airspace and flight procedure development so that they can be better understood when viewing local community, airport, and other stakeholder concerns.

Part 1: Difference between Conventional and RNAV Flight Procedures
Historically, flight procedures were built around ground based navigation aids from
which aircraft would receive signals/guidance to navigate along their flight paths. Today,
these are known as “Conventional” flight procedures. Figure 1 shows a current
Conventional flight procedure into San Francisco airport where the ground based
navigation aids are fundamental to the procedure and are identified by red circles.

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The expanding role of remote air traffic control towers. Do they provide improved efficiency?

Remote Air Traffic Towers: An expanding role

This month, the Reason Foundation, released a study about Remote Air Traffic Control towers as a possibility to enhance safety, reduce costs, and expand services at smaller airports. These are being proposed as an alternative to Contract Towers staffed with non-federal employees in light of the recent FAA budget challenges.

The concept is not new and has been tested in Europe successfully. In fact, much of today’s air traffic system is, relatively, remote. Local operations are supported by air traffic control towers located on the airfield they service. Beyond that, approach and departure control is provided by facilities that are often not located on the field but can be much further away. Outside of the approach and departure airspace, the enroute controllers take over and issue tactical commands from hundreds of miles away. Couple this reality with the success in Europe, and this concept is feasible. Right now, aviation is receiving a tremendous amount of attention from local citizens, government officials, and now private companies with the recent announcements by President Trump. In light of all of this, it is very important to remember that aviation is a system with many components that are heavily interrelated.

All aviation projects have borne out a single truth: The only successful aviation implementation occurred when the system as a whole was addressed. Remote towers are an interesting idea. However, any pursuit of this concept on a wider basis must address all elements of this diverse and complex infrastructure. Technology is great, but the contingencies must be addressed and part of the whole system. This has been part of BridgeNet’s core philosophy through its 20+ years of operation and it has never been proven to be more true than in today’s environment.


About the Author: Grady Boyce is a current and active Captain for a major airline flying the B-737. He has participated in, and led, airspace developments and ATC modernization efforts on all continents except Antarctica. Grady is a consultant to BridgeNet bringing flight procedure development, ATC expertise, and TERPS assistance into their current and future activities.

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Can the courts determine how an aircraft flies to lower the impact of noise?

Court Challenges and Plane Noise

In a recent article on WTOP.COM (http://alturl.com/njue4), Kate Ryan highlights recent considerations in Rockville, MD where the city council president is considering whether it can change flight patterns through the judicial process.

Flight procedure development is a complex process that involves input from many different stakeholder communities and compliance with FAA directives as to how these procedures are engineered. It is not a simple process. Let’s start this review from the high-level perspective. Next time you step outside, look up and make an assessment of the airspace above you. What is it like? What do you see? Is it congested or lightly traveled? The most common response to this question is that “it is not too congested” unless the person being asked lives in a community close to an airport. Then, the answer is obviously different. In truth, unless you are in northern Canada, the airspace above you is very congested and highly structured.

Airspace is divided into sections and those sections are further divided into sectors based on altitudes. Connecting those sectors are airways for aircraft, or corridors used to transit an aircraft from one sector to another. When adverse weather is added to this picture, the entire airspace system can be completely reshuffled in a moment. Further, within these sectors are buffers that are added to keep aircraft separated, since aircraft don’t look kindly on impacting other aircraft.

The flight paths that are built have to accommodate aircraft from the weekend flyer, helicopters, military aircraft, and commercial airlines of all sizes and performance capabilities. Therefore, a wide variety of aircraft performance characteristics have to be considered and accommodated for. The above is a very brief overview of a long process that is very involved and complicated. The legal challenges that are being considered by Montgomery County and other locations around the country, pose an interesting question: Can the courts determine how an aircraft flies? At BridgeNet, we believe in, and have successfully participated in, a different path.

Over the years, the FAA has developed a series of criteria documents that have provided a safe structure to our aviation system. Additionally, they have developed documents that outline how flight path design is to be performed and what stakeholder groups should be involved. As with any area of our lives, flight procedure and airspace development is a compromise of many different organizations, needs, and aircraft capabilities. Many individuals on our staff have implemented successful airspace and flight path changes around the world. This can be accomplished in the United States as well with a mix of education, compromise, and a willingness to succeed.


About the Author: Grady Boyce is a current and active Captain for a major airline flying the B-737. He has participated in, and led, airspace developments and ATC modernization efforts on all continents except Antarctica. Grady is a consultant to BridgeNet bringing flight procedure development, ATC expertise, and TERPS assistance into their current and future activities.

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Is Privatizing Air Traffic Control Services an Improvement?

Recently both the President and Congress have pushed for privatization of Air Traffic Control in an effort to what some see as a broken and antiquated system, and to stimulate modernization from RADAR to a GPS based system. As a long time user of the current air traffic system, I applaud the modernization efforts, but am not sold on the idea that this proposed path will achieve the desired effects.

Over the last decade, I have participated in, and led, many FAA airspace modernization efforts, including NextGen and Metroplex. All of these efforts have moved away from older technology and towards a more modern airspace system. The results of using new technology and GPS in our current airspace system are measurable, repeatable, and must continue to be pursued. However, the time frame of such improvements, admittedly, can feel as if they are measured in glacial timescales and this leads to the angst of many seeking some changes. I have been one of those frustrated stakeholders in the past. However, the air traffic system is a massive and complex being.

A common mistake in viewing and seeking changes in the current system is that of viewing a sought change in a local-only perspective. It is easy to look up to the sky and think: “There is a lot of empty sky up there. Why can’t we just move a flight path over there, or use the technology in my cell phone to help navigate.” It should be remembered that the FAA does not just represent one stakeholder of the aviation system, but instead, have been tasked with representing all stakeholders. Movement of an airspace structure or flight path has to be viewed in totality and not locally. Making changes to aircraft navigation systems have to be viewed from the general aviation perspective to commercial airlines. This is a daunting task and can lead to delays. Having said that, I have also witnessed some cultural issues in the FAA where departments are risk averse and siloed. This is a problem just as difficult as managing broad changes that affect all stakeholders. How will privatization affect this?

The idea of privatization is one approach to addressing a broad array of issues affecting the current air traffic system. Perhaps individual corporations bidding on these opportunities will drive down operational costs on the system as a whole. However, a few questions arise that should be addressed as this concept moves forward: 1) Who will maintain a national standard for air traffic? Who will enforce this? 2) How will coordination be seamless across different air traffic service providers? Will their systems be cross compatible? 3) While these new organizations will provide air traffic services, will they also be mandated with making improvements to the system? Will they also be mandated to address noise and other environmental concerns? 4) How will privatization improve the acceleration of new technology in current and future aircraft? Will the FAA still maintain control of this responsibility? Finally, and perhaps most importantly, 5) Who, and how, will the current level of safety be maintained and improved?

There are many considerations in this proposal that must be fleshed out further. I used to think this whole process was “simple”, then I became deeply involved in these processes around the world working with many different cities, airlines, airplane manufacturers, and governments. Aviation is a massively complex system with significant safety implications. If this path is to be pursued, all stakeholders must maintain a methodical and pragmatic approach to this as the law of Unintended Consequences will surely be a constant challenge.

About the Author: Grady Boyce is a current and active Captain for a major airline flying the B-737. He has participated in, and led, airspace developments and ATC modernization efforts on all continents except Antarctica. Grady is a consultant to BridgeNet bringing flight procedure development, ATC expertise, and TERPS assistance into their current and future activities.

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