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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
Performance-based Horizontal Separation Minima (PBHSM) for both lateral and longitudinal separation in Fukuoka Flight Information Region (FIR).


The purpose of an EMA is to evaluate airspace safety before implementation of PBHSM and to continue safety monitoring after implementation.

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 PBCS 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

Copyright(C) 2011 Japan Airspace Sfety Monitoring Agency. All Rights Reserved.