A dynamic simulation was conducted to provide an initial and limited investigation into the operational and procedural problems that may exist when intermittent positive control (IPC) is present within a terminal area air traffic control (ATC) system. The simulation was performed at the National Aviation Facilities Experimental Center (NAFEC) and utilized the digital simulation facility (DSF). The test environment simulated a single Discrete Address Beacon System (DABS) sensor site and used the IPC algorithm provided by the MITRE Corporation. The results indicated that the algorithm tested at NAFEC adversely interacted with the present ATC system in a number of operational areas. Rather than remaining passive until required, IPC generated controller alerts and, at times, commands when controllers were following normal procedures and aircraft pairs were well outside ATC separation standards. These unnecessary alerts occurred most frequently between arrivals in the final approach area and between arrivals and departures in those areas where routes crossed. The arrival encounters usually involved high closure rates, and, in general, all encounters demonstrated that a lack of knowledge of ATC intent and a sensitivity to controller technique precipitated the premature IPC activity. Data indicated that significant reductions in the number of IPC messages generated could be achieved by reductions in IPC threshold parameters. Modifications to control procedures could produce similar reductions, but were not considered acceptable because of the tendency toward increased workload and reduced operations rates. A comparative analysis between an airborne collision avoidance system and IPC is provided.

  • Corporate Authors:

    National Aviation Facilities Experimental Center

    Federal Aviation Administration
    Atlantic City, NJ  United States  08405
  • Authors:
    • Rossiter, S
    • Windle, J
    • Strack, R
    • Mullen, W
  • Publication Date: 1977-1

Media Info

  • Pagination: 90 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00151500
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: FAA-RD-76-193 Final Rpt., FAA-NA-76-32
  • Files: NTIS, TRIS, USDOT
  • Created Date: Apr 13 1977 12:00AM