Behind the Scenes of NextGen.
Austrian et al conducted a 2012 study to identify potential human performance related hazards associated with the Next Generation Air Transportation System (NextGen). The resulting data will reveal the likely impact of these hazards on the Traffic Management Unit (TMU) and therefore on the safety and efficiency of the National Airspace System (NAS).
The study focused on Segment Bravo, a series of seven solution sets incorporating related Operational Improvements (OIs) due to be implemented into the NAS in 2016.
Four solution sets were deemed most appropriate for analysis.
Each solution set was ranked according to potential for risk.
Table 1. Segment Bravo Solution Set TMU Relative Risk Rankings
|Solution Set||Acronym||Relative Risk Rank|
|Trajectory Based Operations||TBO||1|
|High Density Airports||HD||2|
|Collaborative Air Traffic Management||CATM||3|
|Flexible Terminals and Airports||FLEX||4|
The OIs for each solution set were also ranked according to their potential for human performance related hazards.
Table 2. Segment Bravo Operational Improvements TMU Relative Risk Rankings
|Operation Improvement||Solution Set||Risk Rank|
|108206: Flexible Airspace Management||TBO||1|
|104122: Integrated Arrival/Departure Airspace Management||HD||2|
|104128: Time-Based Metering in the Terminal Environment||HD||3|
|102114: Initial Conflict Resolution Advisories||TBO||4|
|105302: Continuous Flight Day Evaluation||CATM||5|
|104209: Initial Surface Traffic Management||HD||6|
|105208: Traffic Management Initiatives with Flight Specific Trajectories||CATM||7|
|104120: Point-In-Space Metering||TBO||8|
|104117: Improved Management of Arrival/Surface/Departure Flow Operations||HD||9|
Hazards associated with TMU activity were identified. The En Route domain job description relating to TMU job activities and job sub activities resulted in the identification of four sub activities listed according to risk ranking within the Segment Bravo solution sets. Responding to changes in airspace status resulted in the greatest potential for risk and related directly to OI 108206 - Flexible Airspace Management, the highest risk rated OI.
Table 3. TMU Impacted Sub-Activity Relative Risk Rankings.
|Sub-Activity Description||Relative Risk Ranking|
|S35: Responding to changes in airspace status||1|
|S26: Responding to traffic management initiatives||2|
|S34: Responding to requests for temporary release of airspace||3|
|S25: Managing arrival flows and approach sequences||4|
The HESRA (Human Error and Safety Risk Analysis) hazard identification process was used to assess the severity, likelihood, and recovery of human performance hazards within the Segment Bravo solution sets and OIs and Risk Priority numbers (RPN) assigned to each hazard. This will greatly assist in the identification of threats within the TMU and clarify the many variables before implementation of the new procedures.
The HESRA hazard identification process was used in conjunction with discussions with ATC and human factor experts to establish potential Segment Bravo solution set hazard conditions and assign risk rankings. The collaboration with experts in their field minimises the risk of allowing potentially hazardous conditions to intrude undetected into the design of NextGen.
The FAA's Safety Management System (SMS) likelihood and severity scales were used to ensure commonality with the FAA safety system, further enhancing standardisation.
Table 4. TMU Impacted Sub-Activity Relative Risk Rankings.
|Extremely Low Risk||• No system or safety implications. • No further design or evaluation efforts required.|
|Low Risk||• No significant system or safety implications. • Unlikely that significant design, training, or procedural changes will be required.|
|Moderate Risk||• Potentially significant system or safety implications • Possible that significant design, training, or procedural changes will be required.|
|High Risk||• Significant system or safety implications. • Likely that significant design, training, or procedural element will be required.|
|Extremely High Risk||• Critical system or safety implications. • Significant design, training, or procedural changes are required before the system is deployed.|
- Trajectory Based Operations. TBO
- Flexible Airports and Terminals. FLEX
- Collaborative Air Traffic Management. CATM
- High Density Airports. HD
The HESRA evaluation process identified many OIs associated with the solution sets. Those OIs chosen for this study are listed in Table 2. Segment Bravo Operational Improvements TMU Relative Risk Rankings.
The Segment Bravo solution sets and the number of associated OIs were grouped to allow risk rankings.
Table 5. NextGen Segment Bravo Solution Sets
|Trajectory Based Operations||TBO||6|
|High Density Airports||HD||7|
|Collaborative Air Traffic Management||CATM||6|
|Flexible Terminals and Airports||FLEX||14|
Significant generalisation. The data provided will be of great benefit to the designers of NextGen systems and procedures. The data will be of direct benefit to the TMU when implementing operational strategies, and to air traffic controllers whose airspace will be affected by the strategies of the TMU.
AUSTRIAN, Edward M, BERRY, Katherine A, SAWYER, Michael W (2102). Behind the Scenes of NextGen: Describing the Impact of NextGen Operational Improvements on the Traffic Manager. Proceedings of the Human Factors and Ergonomics Society Annual Meeting 2012 56: 6 DOI: 10.1177/1071181312561022