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With the introduction of technologies like ASAS (Airborne Separation Assistance Systems) and ADS-B (Automatic Dependent Surveillance), future flight crews may be faced with increased responsibility for separation assurance during all phases of flight. One example is Airborne Information for Lateral Spacing (AILS) approaches to close parallel runways in Instrument Meteorological Conditions (IMC) will increase the capacity of parallel runways to be equivalent to those in VMC conditions.

Air traffic control systems have currently reached a “bottleneck” on flights they can safely manage, forcing flight crews to assume some responsibilities. Currently, the flight crew is not responsible for separation management, but they are responsible for the safety of their own flight. Future operational concepts shift the responsibility for separation and appropriate evasive maneuvers from ATC to the flight deck. NASA’s goal is to enable fully airborne self-separation, but this would require extensive training and surveillance equipment on flights.
Automatic Dependent Surveillance – Broadcast (ADS-B) In and Out is an essential capability within NextGen implementation plans. It is also featured in SESAR. GNSS and GPS services are essential for full ADS-B capabilities.
Certain OEMs may have recently moved away from the self-separation operational concept.

Potential hazard

  1. Complex air/ground systems
  2. Intent and reasoning systems not well understood by the pilot
  3. Unfamiliar, and unanticipated characteristics and interfaces (also when partial system lessons learned from another region will need to be absorbed)
  4. Systems approach a semi-autonomous status with interfacing systems without awareness by the flight crew
  5. Systems given limited control of the vehicle independent of the crew
  6. Lack of clarity when responsibility has been reassigned and how it may vary by phase of flight and type of airspace.
  7. Breakdown in the fusion of current (radar) and near-term surveillance technologies (ADS-B In/Out) plus the procedures and phraseology that goes with them.
  8. NextGen/SESAR hazard condition: Controller assists with weather avoidance, but overall responsibility remains with pilot. Associated human performance hazard: Sector controller fails to notice pilot request for assistance.
  9. Computer-to-computer transfer of separation responsibility does not occur properly.
  10. Ground based conflict resolution not calculated. With increasing levels of traffic, TCAS may not provide a robust defense.

Corroborating sources and comments (Report by NASA on separation assurance and function allocation in flight. Currently, ATC has reached a “bottleneck” on flights it can safely manage, forcing flight crews to pick up the slack. The eventual goal is airborne self-separation, but this would require extensive training and surveillance equipment.) (Dated 1999, this informational report looks at the relevance of separation management and some proposed early mechanisms. No word on cyber-augmentation or automation of the task, unlike in the NASA brief.) Separation Assurance and Collision Avoidance Concepts for the Next Generation Air Transportation System, John P. Dwyer, Boeing Research & Technology Center and Steven Landry, School of Industrial Engineering, Purdue University.

FAA/EUROCONTROL Cooperative R&D, “Principles of Operations for the Use of ASAS”, 2001

FAA AVS Workplan for NextGen 2012, P. 73

OI 102137 – Automation Support for Separation Management: ANSP automation enhancements will take advantage of improved communication, navigation, and surveillance coverage in the oceanic domain. When authorized by the controller, pilots of equipped aircraft use established procedures for climbs and descents.

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