In Atlanta, in June 2014, one of the last events at Aviation 2014, the annual forum hosted by the American Institute of Aeronautics and Astronautics (AIAA), was conducted by the five NASA officials in charge of carrying out the new strategic vision of the agency’s Aeronautics Research Mission Directorate (ARMD). In outlining the six new “strategic thrusts” for the directorate’s research, Robert Pearce, Director for Strategy, Architecture and Analysis at ARMD, said the agency must be able to embrace future “big ideas” while adapting to the breakneck pace at which both the business practices and the technology of aviation are evolving.

One of the six new research thrusts outlined by the ARMD in the summer of 2013 was “real-time, system-wide safety assurance.” The two modifiers in that phrase – “real-time” and “system-wide” – indicate the key challenges that lie at the heart of NASA’s research into assuring safety in the National Airspace System.

One of the NASA panelists was Dr. John Cavolowsky, program director for ARMD’s new Airspace Operations and Safety Program (AOSP) – which combines elements of two existing research programs, Airspace Systems and Aviation Safety. The reason for the integration of these two programs, Cavolowsky explained, was that it had already become impossible to consider the issues separately. “To suggest that Airspace Systems had not been addressing safety before is wrong,” he said. “We have been. But the opportunity to bring in some of the advanced capability that has been driven aggressively through the Aviation Safety Program over the years is providing far greater additional value and integration of our capabilities.”

The rapidly developing technologies and capabilities being investigated by ARMD researchers to increase the capacity, efficiency, and autonomy of the air traffic management (ATM) system are also important tools in assuring overall safety. Likewise, the former structure of the Aviation Safety Program, which divided areas of research into those aimed at vehicles, the air transportation system, and environmental hazards, no longer reflects the complexity of technological development. The increasing integration of onboard sensors, software, and operational systems with ground- and satellite-based control systems has muddied such distinctions. The future of aviation is one in which aircraft and control systems – and pilots, when necessary – will function increasingly as one, not only reacting to, but eventually anticipating and avoiding, potential threats to safe aviation.

Merging the program structures into the AOSP, said Cavolowsky, gives ARMD researchers the ability “to provide a strong integration and interrelationship of those elements and development of quality products going forward – not just for the operational element, but for the safety element of the overall system.”

One of the six new research thrusts outlined by the ARMD in the summer of 2013 was “real-time, system-wide safety assurance.” The two modifiers in that phrase – “real-time” and “system-wide” – indicate the key challenges that lie at the heart of NASA’s research into assuring safety in the National Airspace System.

 

“System-Wide” Assurance

One of the inefficiencies in today’s air traffic management system is that it’s managed by people at either end of individual flight paths, tasked with granting clearances for takeoff and landing; their focus, by definition, is on a conflict-free handover to someone else. An aircraft’s movement from sector to sector, over time, can create a mismatch between the capabilities of a ground control system and the dynamics of flight data (i.e., unexpected conditions) encountered by an onboard flight management system – and this mismatch can create downstream problems such as delays and safety risks.

The Federal Aviation Administration’s (FAA) vision for modernizing the National Airspace System, the Next Generation Air Transportation System (NextGen), includes the concept of trajectory-based operations (TBO) – devising an optimal point-to-point trajectory for an aircraft based on data gathered from every appropriate source throughout the air traffic management system. The shift from clearance-based to trajectory-based operations will offer several distinct advantages:

• Aircraft trajectories will be precisely executed through four dimensions (the three spatial dimensions and time);
• Details of these trajectories will be shared by all concerned parties, end-to-end, using system-wide information management tools;
• In the case that a trajectory must be altered, these information management tools will allow full knowledge of downstream effects – and therefore selection of the least troublesome alteration; and
• The increased end-to-end certainty about trajectories will allow for more aircraft to be inserted into a given volume of airspace.

The capabilities that will allow for true TBO, including real-time knowledge of planned trajectories and en-route conditions throughout the air traffic management (ATM) system, have not yet been integrated into the NextGen architecture – but NASA is working on it.

 

“Real-Time” Modeling

Early research into aviation safety, by necessity, required a look back at the issues and factors that had contributed to accidents. “Early on in the safety research program,” said Dr. Jessica Nowinski, a NASA research psychologist who studies aviation system safety, “we were more focused on retrospective analysis of what we call the ‘tall poles’ – the most frequent causes of accidents and incidents. But because aeronautics will be focusing on new and developing technologies, we really need to address the safety issues in conjunction with the development of those new tools and concepts. Now we’re trying to be even more proactive and look at what safety issues might develop with the introduction of new operations – because the technology is developing so quickly, we really don’t want to wait and see what problems arise. We want to be able to address vulnerabilities before they become problems.”