It was an event that reverberated inside and outside of the aviation industry.
A cargo plane on approach to land at Austin-Bergstrom International Airport in Texas nearly collided with a passenger plane that had been cleared for take-off on the same runway. Only the last-minute evasive action from the pilot of the cargo plane prevented a catastrophic event.
The ensuing investigation examined a number of factors influencing the event. Among them included lack of ground technology for air traffic controllers to monitor traffic on the taxi and runways as well as lack of physical visibility from the tower 200 feet above the ground to a fog-hidden airfield.
Any discussion of airport safety must begin with the acknowledgement that, statistically speaking, aviation is by far the safest mode of transportation in the United States. That is due to an unprecedented collaborative effort between government, airplane manufacturers, airport operators, and airport engineers and designers who all set a goal of zero fatalities in air travel. The incorporation of technology and sensors both inside and outside the plane and in the control towers has elevated how safely airplanes can operate in an increasingly crowded environment both in the air and on the ground. Even general aviation facilities, which do not benefit as greatly from the Part 139 oversight, or extensive technological investment that commercial airports enjoy, can greatly enhance safety through easily implementable design alterations that will reduce incursions, incidents and accidents.
Yet, as the incident in February in Austin illustrated, airport and airplane operations are still a human activity. For all of the technology that can be incorporated in and outside of the cockpit to mitigate human error, airports still need to be designed for human activity since what is being moved in, through and out of an airport are humans.
Unfortunately, the case from Austin is not an outlier. Workforce challenges in the cockpit, as well as the tower, have created significant turnover and shortages in staffing and experience. Aging technology and infrastructure also challenge airport operations at a time when passenger traffic has rebounded to near all-time highs. The convergence of all of these factors puts new pressure on that collaborative group to question the collective responsibility to safe operations and how safety can be enhanced in the next phase of aviation travel.
Team approach to safety
Airplanes are designed primarily to fly – a remarkable achievement in physics but one that leaves them limited and cumbersome when making the transition from land to air. As a design vehicle, aircraft are at their weakest on the ground, which is why it is not surprising that the majority of aviation accidents occur at or near the airport.
If you envision an airplane as strictly a ground-design vehicle, it leaves much to be desired. The aircraft's length, width/height, and wheelbase make them unwieldy for any type of maneuvering other than straight. They require great impulse thrust to even get in motion. They don’t play nice with grade changes and have obstructed lines of sight. They can’t even go in reverse!
Therefore, an airport’s purpose is to transition a plane from the ground to the air and back down again. Through their layout and geometry, they are designed to maximize safety, while increasing efficiency of airport operations.
Nearly 50 years of data show that more than 60% of all aviation accidents/incidents occur on and near the airport environ. This includes accidents occurring during ramp and taxi operations, takeoff, initial climb, as well as approach and landing. Even though sentinel events are rare in the U.S., even a wing clip can have a significant ripple effect within the entire system: It can take that plane out of service and create delays for dozens of flights across the nation.
Despite similar operational characteristics, airports are not cookie-cutter in design. While the Federal Aviation Administration (FAA) standardizes the design of airports, the layout, airspace, and intended use at each operation create a unique and customized facility to serve the particular needs and dynamics. A key facet of the airport’s design is to enable the pilot to know exactly where they are in relation to where they are trying to go. It’s a function of both improving situational awareness and guiding to the intended destination in an efficient manner. This includes not only aircraft maneuvering by pilots but air traffic controllers, operations also personnel/vehicles.
That carefully planned and designed environment - working in tandem with pilot training, pilot health screenings, airplane manufacturing, ground and air instrumentation, and air traffic control - is what makes air travel today the safest form of transportation.
Finding safety options within standards
Many airports around the U.S. were originally designed in the WWII era and have been modified and expanded as aviation evolved into its current form. Wider and longer aircraft, increased performance, high traffic volumes, airspace, and even changing demographics in a community can impact airport operations. As the aviation industry continues to grow, change, and develop, the designer plays an integral role in ensuring and enhancing airport safety through design.
In the decades since aviation evolved from primarily mail service and military operations to a key component of the U.S. transportation infrastructure for moving people and goods, the FAA has conducted extensive studies to determine standards for design. Within those standards, however, the designs must reflect the unique nature of a particular airport’s location and operations. An airport designer’s job goes beyond simply meeting standards and rises to a mindset of employing the layout, materials, and other physical enhancements of humble infrastructure to increase safety within a particular airport’s dynamics.
For example, as Pigeon Forge, Tenn. grew as a tourist destination, the airport had to facilitate more enplanements and accommodate wider aircraft. Expanding the airport changed the separation standards to the point that the runway was too close to the terminals, ramps, and hangars. Resolving the challenge required a new runway. In Pigeon Forge, shifting the runway a few degrees – although not mandated by the standards – improved the precision for approaches and created a safer operation for pilots, while setting the stage for future growth in a safer and more efficient manner.
A similar tactic, but to a larger degree, took place for Lanett Municipal Airport in Lanett, AL. When the land locked airport needed to grow, engineers turned to a “re-orientation” of the runway and the whole airfield proper. This enabled increased safety for larger aircraft, greater approach compatibility, and provided a new terminal area to sustain long term growth and development.
The FAA has been keenly aware of the integral role that design plays, and recently updated guidance on Problematic Taxiway Geometry and Runway Incursion Mitigation including airport Hot Spot identification and visual aid improvements. The key challenge for the designer is to use their creativity, ingenuity, and unique role within the system to move beyond basic compliance in order to exceed those standards and improve safety and operations to an even greater degree.
At Montgomery Regional Airport, the FAA identified two “hotspots”, or areas with a potential risk of runway incursion or collision exists. The airport designers worked with FAA to ensure pilots must make a conscious turn and enhanced lighting and signage in this area to heighten situational assessment. Upon completion of the project, the geometry was no longer listed as a hotspot.
For airport operators, the biggest challenge is bringing entire operations up to standards while keeping the airfield flexible for growth and ever-changing standards. More than an endpoint, though, it’s a process, not only to remain compliant but also to manage outdated layouts and accommodate innovations and security measures meant to improve aviation travel.
Beyond pavement
Not everything that needs to be done can be accomplished all at once. Modernizing operations is a muti-pronged approach that requires a comprehensive strategy to meet the individual needs of an airport, from the development vision of the owner down to the markings/signage that indicate where ground crews should and should not be and situational awareness for pilots.
Modernization and expansion strategies require a holistic, ecosystem approach that aligns the design to all of these complementing and sometimes competing components. Employing this broad view, a modernization project can take what is already a complex operation and mitigate any confusion that would be created by the design and construction of new infrastructure to meet evolving needs.
It’s a delicate balance to make sure the airport and the community are mutually compatible in terms of balancing growth and development with land use requirements for implementing safety improvements. An example that has challenged airports as standards have updated are with vertical obstructions. Vertical obstructions are a common problem for airports. Antennas, cellphone towers, and trees around the airport all have an impact on how steeply a pilot must approach. The angle of the approaches may need to be raised, visibility minimums affected, or require a typical approach procedure. While height and land ordinances can be employed to prevent incompatible use, evolving needs can outpace dated protections. An example is the burgeoning VTOL and EVTOL aircraft with the design standards that will be placed on airports still in flux.
It is important to consider that an airport extends beyond its property lines. Designers must consider not just the airport itself but also the land around it, which also needs to be reviewed and analyzed under different conditions that include approach, weather, and equipment. These complexities then must be conveyed to local leaders who may have zoning authority in and around the airport.
Importantly, software modeling, visualizations, augmented reality, and burgeoning AI can also help owners learn more about the design options and the impact of their choices on situational awareness for pilots and air traffic controllers. For example, taxiway geometry, historically designed for efficiency and expediency, has not always led to clarity for pilots. The resulting outcome is wrong runway takeoffs because of reduced situational awareness.
By designing geometric configurations that direct pilots to where they need to go, akin to roundabouts used for motor vehicle traffic, airports can improve situational awareness by guiding pilots through a predetermined director or slowing movement. In roadway design, measures such as roundabouts and speed bumps are referred to as traffic calming. A good airfield designer can utilize the same theory to not so much calm traffic, but increase situational awareness and subtly guide aircraft without sacrificing efficiency.
By taking proactive steps, airport operators and users of their facility can reduce their liability exposure of accidents and incidents, helping not only safety but the bottom line.
Levels of safety to whole system
Although technology has advanced safety in many ways, the human element in safe operations is essential to understand each person, including the airport designer has a responsibility to safety and awareness. This includes from the basic design to how changes (sometimes significant) can alter the standard profile at the field. These changed conditions, whether temporary or permanent, can present significant dangers that pilots need to monitor beyond trusting their instruments.
Even as new technology is developed to mitigate human error, such as autonomous operation, the integration of that technology will present its own challenges and opportunities for airports, like possible upgrades to markings signage and configuration to assist the sensor suite of these systems. Additionally, the terminal environment will change as well with the increased strain on the electrical grid around an airport and aircraft charging, servicing, and firefighting of electric systems.
Therefore, improving the safety of airport operations is a dynamic process that requires looking at the airfield as an ever-evolving entity. An airport team is comprised of many stakeholders with varied responsibilities - from managers and manufacturers to pilots controllers, and the airport designer. Including an aviation design specialist who can eye the entire operations from a 30,000-foot view and utilize maintenance and development projects to not only ensure airport owners to maintain FAA compliance, but also lay the foundation for the future.
From what is visible, like the angle and position of runways, to what is unseen, such as design surfaces, approach paths, and even stormwater drainage, there are levels of safety that must be examined to improve overall operations. It goes beyond short-term fixes and immediate needs to include long-term solutions that improve quality and the adaptability of the entire airport.
Projects need to be examined with a lens that looks outside of the aviation sector for insights to safety improvements. While FAA and state grants may have strict stipulations for how the funds are applied, thinking creatively about solutions to complex problems can effectively meet the compliance standards and increase the situational awareness necessary to improve safety.
Many safety considerations are outside of an airport’s control, such as pilot and air traffic controller staffing and training. However, that does not suggest that airports are at the mercy of these human challenges. By leveraging the specialized expertise of aviation planners, designers and engineers, airport leaders can ensure that their operations will continue to play a key role in maintaining aviation’s status as this country’s safest mode of transportation.
