53. Use of materials, processes, parts and periodical overhaul of aircraft- (1) Every aircraft required under these rules to be provided with a certificate of airworthiness and aircraft components and items of equipment on such aircraft shall periodically be inspected, overhauled and certified on completion of the prescribed flight time or calender time or on the basis of any other stipulated condition in accordance with the approved maintenance schedules or approved maintenance system. Such inspection and certification shall be effected by appropriately licensed engineers or authorised persons as may be specified by the Director-General.

(2) A certificate to be issued in pursuance of sub-rule (1) shall not be issued unless the materials, processes, parts, method comply with such designs, drawings, specifications or instructions as may be issued by the manufacturers or as may be specified or approved by the Director-General. The method and workmanship shall be in accordance with standard aeronautical practice or as may be approved by the Director-General.

(3) Notwithstanding the foregoing provisions, the Director-General may grant exemption by general or special order in writing to any person or class of persons from the operation of the foregoing sub-rules either wholly or partly, subject to such conditions, if any, as may be specified in such order.