(2)If any recording facility provided in compliance with sub-rule (1) ceases to be capable of recording the matters required by that sub-rule, it shall be ensured that, as far as practicable, a record of the following is kept in writing -(a)a summary of voice communications exchanged between the Aeronautical Telecommunication Station and aircraft by Air Traffic control unit; and(b)voice communication, message exchanged with other Aeronautical Telecommunication Station.