17/8/11 AERODROME METEOROLOGICAL OBSERVATION AND FORECAST STUDY GROUP (AMOFSG) NINTH MEETING Montréal, 26 to 30 September 2011 Agenda Item 5: Observing and forecasting at the aerodrome and in the terminal area 5.1: Observations AMENDMENT TO VISIBILITY SPECI CRITERIA (Presented by Hu Jiamei) SUMMARY This paper proposes that the SPECI criteria for visibility 1500 m, as defined in Annex 3, be aligned with the visibility threshold 1600 m of basic take-off and non-precision approach and landing operations, as defined in ICAO Doc 9365. 1. INTRODUCTION 1.1 China has done a comprehensive review of the meteorological information provided from the Air Traffic Management Bureau (ATMB) since last August, which is the main aeronautical meteorological service provider in support of airline operations. This review included consultation with the dispatchers and pilots. Following these discussions a proposal was developed that the SPECI criteria for visibility 1500 m defined in Annex 3 Meteorological Service for International Air Navigation, be aligned with the visibility threshold 1600 m of basic take-off and non-precision approach and landing operations, as defined in ICAO s Manual of All-Weather Operations (Doc 9365). (6 pages) AMOFSG.9.SN.027.5.en.doc
- 2-2. DISCUSSION 2.1 ICAO Annex 3 Meteorological Service for International Air Navigation currently states in Appendix 3 Para. 2.3.3 2.3.3 Recommendation. Where required in accordance with Chapter 4, 4.4.2 b), SPECI should be issued when ever changes in accordance with the following criteria occur: b) when the visibility is improving and changes to or passes through one or more of the following values, or when the visibility is deteriorating and passes through one or more of the following values: 1) 800, 1 500 or 3 000 m; and. 2.2 ATMB of China provides SPECI that are compliant with Annex 3. 2.3 It is noted that the SPECI visibility threshold 1500 m is not applied in the Aerodrome Operating Minima of China listed in Appendix A, which actually results in the disuse of SPECI for visibility passing through 1500 m. Instead visibility threshold 1600 m is not only defined in most cases of the Aerodrome Operating Minima of China, but also most widely used in real aircraft operations, according to the feedback from airlines customers. 2.4 It is also noted that ICAO Annex 6 Operation of Aircraft, Part I International Commercial Air Transport Aeroplanes just defines the categories of precision approach and landing operations with ICAO Doc 9365, listed in Appendix B, as the guidance on the establishment of aerodrome operating minima. Aerodrome Operating Minima of China was established primarily based on ICAO Doc 9365. 2.5 It can be seen that the first visibility threshold 800 m of SPECI is applied in ICAO Doc 9365, Para. 6.3. Accordingly, the second visibility threshold of SPECI is supposed to be the most representative among the rest of basic take-off minima and commonly acceptable non-precision approach minima as given in ICAO Doc 9365, which is 1600 m. 3. RECOMMENDATION 3.1 To meet the aviation operational requirements and align with ICAO Doc 9365, it is recommended that SPECI criteria for visibility and some other related items in ICAO Annex 3 be reworded as follows: ICAO Annex 3, Appendix 3 Para. 2.3.3 2.3.3 Recommendation. Where required in accordance with Chapter 4, 4.4.2 b), SPECI should be issued when ever changes in accordance with the following criteria occur: b) when the visibility is improving and changes to or passes through one or more of the following values, or when the visibility is deteriorating and passes through one or more of the following values: 1) 800, 1 500 1600 or 3 000 m; and
- 3 - AMOFSG/9-SN No. 27 ICAO Annex 3, Appendix 5, Para. 1.3.2 1.3.2 Recommendation. The criteria used for the inclusion of change groups in TAF or for the amendment of TAF should be based on the following: e) when the visibility is forecast to improve and change to or pass through one or more of the following values, orwhen the visibility is forecast to deteriorate and pass through one or more of the following values: 1) 150, 350, 600, 800, 1 500 1600 or 3 000 m; or ICAO Annex 3, Appendix 5, Para. 2.2.3 2.2.3 Visibility When the visibility is expected to improve and change to or pass through one or more of the following values, or when the visibility is expected to deteriorate and pass through one or more of the following values: 150, 350, 600, 800, 1 500 1600 or 3 000 m, the trend forecast shall indicate the change ICAO Annex 3 4.6.3.3 The runway visual range, assessed in accordance with 4.6.3.1 and 4.6.3.2, shall be reported in metres throughout periods when either the visibility or the runway visual range is less than 1 500 m 1600m. ICAO Annex 3, Appendix 3 4.2.4.4 Recommendation. In METAR and SPECI, visibility should be reported as prevailing visibility, as defined in Chapter 1. When the visibility is not the same in different directions and a) when the lowest visibility is different from the prevailing visibility, and 1) less than 1 500 m 1600 m or 4. ACTION BY THE AMOFSG 4.1 The AMOFSG is invited to: a) note the content in this paper; and b) support the proposal provided.
Appendix A APPENDIX A THE AERODROME OPERATING MINIMA OF CHINA 7.1. Basic take-off minima is represented by VIS/RVR as follows: a. Standard minima of 800 m for 3- or 4- engine aircraft and b. 1600 m for 1- or 2-engine aircraft 8.6.3 Approach Minima for CategoryⅠ Table 4 Approach Minima for CategoryⅠ Lighting Aircraft Minima VIS/RVR (m) System Category ILS/GLS ILS/(GP failure) VOR NDB APV(LNAV/VNAV) RNP(LNAV) FALS A B C 550 800 800 1200 D 1200 1600 1600 IALS A B C 800 1200 1200 1200 D 1600 1600 1600 BALS and NALS A B C D 1200 1600 1600 1600 11. Circling Approach Minima Table 7 Circling Approach Minima Aircraft Category A B C D MDH (m) 120 150 180 210 VIS (m) 1600 1600 2400 3600
Appendix B APPENDIX B ICAO DOC 9365 -MANUAL OF ALL-WEATHER OPERATIONS, PARA. 6.3 6.3 Tables of Aerodrome Operating Minima
Appendix B B-2 END