MSA sectors 2

28.10.2004

Submission:

What was proposed seems to be possible according to PANSOPS, which indicates in Vol II Part 3 Chapter 9 section/para 9.5 that MSA sectors can be separated/delineated by a DME arc provided that a 5NM sector buffer is used (refer fig III-9-2). Some Tahiti procedure charts published by the French seem to use this approach (others use a conventional single MSA figure). This has resulted in an MSA as follows:

9000FT within 18NM of TAF VOR and to 25NM between R-060 and R-175; 2500FT beyond 18NM between R-175 and R-220; 5000FT beyond 18NM between R-220 and R-310; and 2700FT beyond 18NM between R-310 and R-060.

I assume this allows procedures from the North East to commence at 2700FT rather than 9000FT which might be otherwise required. The only condition seems to be

that the inner area has the lower MSA. In Australia (and PNG) a 360 degree 10NM MSA is commonly provided. This MSA can be used in addition to the 25NM MSA. The 25NM MSA applies from 0 to 25NM (from the nominated aid) for all sectors marked, and the 10NM MSA applies from 0 to 10NM of the nominated aid.

P. Bushell - Procedure Designer - RAAF Aeronautical Information Service - Melbourne - Australia