AMOSSG/3-SN No. 10

2/1/01

AERODROME METEOROLOGICAL OBSERVING SYSTEMS STUDY GROUP (AMOSSG)

THIRD MEETING

Miami, 22 to 25 January 2002

Agenda Item	5:	Review of the requirements for meteorological observations and reports at aerodromes contained in Chapter 4 of Annex 3

COMMENTS ON PARAGRAPHS 4.8.4 TO 4.8.6 AND 4.12.3

(Presented by Benoît Okossi)

SUMMARY
This study notes comments on paragraphs 4.8.4 to 4.8.6 and 4.12.3.

1.	INTRODUCTION

1.1	The following comments are offered concerning paragraphs 4.8.4 to 4.8.6 and 4.12.3:

a)	Paragraph. 4.8.4, line 1: "In local routine and special reports and in reports in the METAR/SPECI code forms.…aviation are as follow." The types of present weather phenomena should be reported in local routine and special reports as well as in the METAR/SPECI code forms. Thus the line added by AMOSSG/2 is justified. Conclusion: agreement with the AMOSSG/2 proposals (in red);

b)	Paragraph. 4.8.4, line 16: Referring to users requirements, small hail and/or snow pellets (GS) is aeronautically less significant than all forms of hails (GR). Thus the removal of GS and keeping of GR is justified. Conclusion: agreement with the AMOSSG/2 proposals to remove GS;

c)	Paragraph 4.8.5, line 1: "In local routine and special reports and in reports in the METAR/SPECI code forms.…abbreviation are as follow." Conclusion: agreement with the AMOSSG/2 proposals (see Comment a));

d)	Paragraph 4.8.5, line 9: "… or lightning seen or detected within 30 km from the aerodrome…". It seems very difficult to estimate the distance at which a lightning can be visible to the naked eyes. Appropriate instruments can detect lightning within and over 30 km. Conclusion: suggest to remove "seen or" in the AMOSSG/2 proposal which becomes "or lightning detected within 30 km from the aerodrome…"

e)	Paragraph 4.8.6, line 1: "…In local routine and special reports and in reports in the METAR/SPECI code forms.…indicated as follows". Conclusion: agreement with the AMOSSG/2 proposals (see Comment a) );

f)	Paragraph 4.8.6, line 4: "(abbreviated plain language).. (METAR/SPECI)"…. Referring to Appendix 2 Annex 3 (14th edition), "abbreviated plain language" is no more used, it has been replaced by "local routine and special reports". Conclusion: agreement with the AMOSSG/2 proposals of adding "SPECI" and removing "abbreviated plain language" and replacing it by "local routine and special reports" ;

g)	Paragraph 4.8.6, line19:"…Not at the aerodrome but…..reported under 4.8.5". Since volcanic ash is one of the most dangerous weather hazards for aviation, the presence of this phenomena in the vicinity of the airport have to be reported in local routine and special reports and in reports in the METAR/SPECI code forms. Conclusion: suggest to remove "only" and replace it by "both in local routine and special report and" and to add « VA,» between "with" and « DS ». So the sentence should read as follows: " – Not at the aerodrome but further away than approximately 8 km from the aerodrome perimeter and used both in local routine and special report and in reports in the METAR/SPECI code forms with VA, DS, SS, ….under 4.8.5"; and

h)	Paragraph 4.12.3, line 1: "In local routine and special reports and in reports in the METAR/SPECI code forms.…supplementary information……REVA". Conclusion: agreement with the AMOSSG/2 proposals (see Comment a) ).

2.	ACTION BY THE GROUP

2.1	The group is invited to take account of these comments when reviewing the draft amendment presented in Study Note No. 2.

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