Aircraft Flight Operation Regulations Article 261

An aircraft shall be provided with radio communication equipment capable of conducting two-way communications for aerodrome control purposes, for receiving meteorological information at any time during flight; and conducting two-way communication at any time during flight with at least one aeronautical station and any other aeronautical stations on such frequencies as may be prescribed by the appropriate authority.The radio communication equipment required in accordance with the preceding paragraph shall provide for communication on the aeronautical emergency frequency 121.5.An airplane to be operated on a flight to which the provisions of on extended flights over water or on flights over designated land areas apply shall, unless exempted by CAA, be provided with radio communication equipment capable of conducting two-way communication at any time during flight with such aeronautical stations and on such frequencies be prescribed by the appropriate authority.The preceding 3 paragraphs shall not apply to free balloons equipped with walkie-talkie devices and operated in an uncontrolled airspace.