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Terminal Sequencing and Spacing


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Program Description

Terminal Sequencing and Spacing (TSAS)

TSAS extend the metering capability into the terminal area by providing tools to terminal ATC and TMU for time-based merging, sequencing and spacing.

Key Capabilities

Key Capabilities

  • Current guidelines for en route controllers are to deliver flights to their meter fixes within +/- 60 seconds of their STAs. TSAS requires improved delivery accuracy (+/-30seconds) to produce the desired flight efficiency gains.
  • GIM-S capabilities enable improved meter fix delivery accuracy
  • Extended Metering allows for en route delay to be absorbed over more sectors and greater distances.
  • Speed advisories help controllers deliver flights to meter fixes with greater precision
Program Benefits


  • Increases the use of Performance Based Navigation (PBN) to improve flight efficiency
  • Supports Optimization of Airspace and Procedures in the Metroplex (OAPM) redesign goals
  • Supports the future use of Flight Deck-Interval Management (FIM)
  • Extends use of time-based metering from the en route domain to the terminal domain and runway, leveraging the FAA's investment in TBFM

Map of Deployment

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