Most ICAO members use the metric system to express visibility. In the weather information for aviation on Teletext I always see visibility in meters and kilometers. However, some time ago the USA refused to adopt the METAR/TAF codes that were agreed by all other members. This also includes the rejection of the hPa, and going on using the inHg. Regrettably Canada joined the US in this, so you see these soft conversions.
----- Original Message ----- From: "Joseph B. Reid" <[EMAIL PROTECTED]> To: "U.S. Metric Association" <[EMAIL PROTECTED]> Sent: Thursday, 2002-09-12 3:14 Subject: [USMA:22174] Re: National Weather Service: temperature in Celsius Jim Frysinger w.rote in USMA 22155: "Nikolay O. Malyarov" wrote: You know what puzzles me here in Canada (among a few other things) - is that the visibility given in the current conditions is a direct conversion from miles (6.4 km, 16.1 km, 24.1 km). Additionally, ceiling is given in feet. Cheers, Nikolay Vancouver, B.C., Canada Sure! The customers are the airline industry members. ICAO, I believe, is the organization that specifies that. Jim Don't blame ICAO). Russia and China follow ICAO rules, which are fully SI. The rest of the world follow American rules because of the dominant position of USA in aviation. These are recognized by ICAO as temporary exceptions; the blue book, if I recall correctly. -- Joseph B. Reid 17 Glebe Road West Toronto M5P 1C8 Tel. 416 486-6071
