Unless you have a 406-MHz emergency locator transmitter (ELT), even your U.S.-registered airplane will be closed to Canadian airspace in approximately two years. Even flights that begin and end in the United States-but with a segment involving transition of Canadian airspace-will not be permitted, based on a decision made recently by Transport Canada that will cover all foreign-registered aircraft as well as those operated under Canadian registration. As of this February, search and rescue satellites will cease to monitor 121.5 MHz, the frequency used by older ELTs. New 406-MHz units typically cost $1,000 plus installation, according to the Canadian Owners and Pilots Association, and are soon to be eclipsed by better technology. The FAA has so far not mandated installation of the new ELTs, and the COPA management has projected that the new ruling will severely cut down on U.S. aircraft operators visiting their northern neighbor. The group estimates that 63,000 foreign-registered aircraft visited Canada last year-90 percent from the United States.