(_f_) as to the cancellation, suspension, endorsement and delivery up of certificates of competency; (_g_) as to the recognition of certificates of competency issued to navigators and other officers under the laws of any British possession or foreign nation which appear to the Board effective for ascertaining and determining their competency; (_h_) as to the fees to be paid on the grant of a certificate and by candidates entering for examination. (3) The regulations shall provide for different certificates of competency being issued in respect of different classes of aircraft, and a navigator or other officer shall not be deemed to be duly certificated in respect of an aircraft of any class unless he is the holder for the time being of a valid certificate of competency under this section in respect of that class of craft, and of a grade appropriate to his station in the aircraft or of a higher grade. (4) If any person— (_a_) navigates or allows to be navigated any aircraft not provided with a duly certificated navigator, and, in the case of any aircraft which is under the regulations required to be provided with other certificated officers, without such other officers; or, (_b_) having been engaged as a navigator or other officer required to be certificated, navigates, or takes part in the navigation of, an aircraft without being duly certificated; or (_c_) employs a person as a navigator or as an officer in contravention of this section without ascertaining that the person so serving is duly certificated; that person shall be guilty of an offence under this Act. COLLISION REGULATIONS 6—(1) The Board of Trade may make regulations (hereinafter referred to as collision regulations) for the prevention of collisions in the air, and may thereby regulate the lights to be carried and exhibited, the fog signals to be carried and used, and the steering and flying rules to be observed by aircraft. (2) All owners and navigators of aircraft shall obey the collision regulations, and shall not carry or exhibit any other lights or use any other fog signals than such as are required by those regulations. (3) If an infringement of the collision regulations is caused by the wilful default of the owner or navigator of the aircraft, the owner or navigator of the aircraft shall in respect of each offence be guilty of a misdemeanour. (4) If any damage to property arises from the non-observance by any aircraft of any of the collision regulations, the damage shall be deemed to have been occasioned by the wilful default of the person in charge of the aircraft at the time, unless it is shown to the satisfaction of the Court that the circumstances of the case made a departure from the regulations necessary. _Alternative for Subsections (3), (4)_