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About the EMA

The En-route Monitoring Agency (EMA) is a part of the JASMA, was established and operated by Japan Civil Aviation Bureau (JCAB), to perform the safety application of Reduced Horizontal Separation Minimum (RHSM) for both lateral and longitudinal separation in Fukuoka Flight Information Region (FIR).


The purpose of an EMA (originally known as Safety Monitoring Agency or SMA) is to evaluate airspace safety before implementation of RHSM and to continue safety monitoring after implementation. The name has been changed recently to EMA, because the agency monitors mainly the en-route phase of Performance Based Navigation (PBN) flights in targeted airspace.

Within the Asia/Pacific Region, the Asia/Pacific Air Navigation Planning and Implementation Regional Group (APANPIRG) is responsible for approving the establishment of an EMA through the Regional Airspace Safety Monitoring Advisory Group (RASMAG). Japan has been approved as the EMA for international airspace in the Fukuoka FIR.


The JASMA covers international, and oceanic airspace, for lateral and longitudinal separation between aircraft flying by RNAV10 (RNP10) or RNP4.


Function-1: Safety Administration

To establish and maintain a database of PBN and other necessary approvals

  • PBN approvals
  • Data Link approvals

To monitor horizontal-plane navigation performance

  • Core Navigational Performance
  • The occurrence of Large Lateral Deviation (LLD) and Large Longitudinal Errors (LLE)

Function-2: Safety Analysis

To conduct safety assessment and reporting results

  • Safety Assessment
  • Establish the Competence Necessary to Conduct a Safety Assessment
  • Assembling a sample of traffic movements from the airspace
  • Process for Determining Whether the TLS is satisfied as the results of a Safety Assessment

To monitor operators' compliance with state approval requirements

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