As above - slack Canadian TAWS requirement.
1998 US proposes TAWS requirement.
2001 US mandates the system.
2003 ICAO recommends TAWS, Annex 6 required TAWS after Jan 2007.
2008 EU mandates TAWS.
1995 Canadian TSB recommends TAWS after Sandy Bay accident.
2000 Canadian Aviation Regulation Advisory Council (CARAC) Recommends TAWS.
2011 Transport Canada Civil Aviation (TCCA) proposes regulations.
Canada finally mandated TAWS in July 2012 (no deviation from ICAO found), to be implemented by retrofit by July 2014.
A very tardy response, particularly when hosting ICAO headquarters.