Section 48. The public safety requiring, and the advantages of uniform regulation making it desirable in the interest of aeronautical progress, that aircraft operated within this commonwealth should conform with respect to design, construction and air-worthiness to the standards prescribed by the United States government with respect to navigation of civil aircraft subject to its jurisdiction, no aircraft shall be operated or navigated within the commonwealth unless such aircraft has an appropriate effective license, permit or certificate, issued by the Civil Aeronautics Authority of the United States or other proper licensing authority and is registered by said authority; provided, that this restriction shall not apply to military aircraft of the United States or possessions thereof, public aircraft of any state or territory, aircraft licensed by a foreign country with which the United States has a reciprocal agreement covering the operation of such licensed aircraft, nor to model aircraft operated in accordance with such regulations as the commission may prescribe, nor to gliders licensed by the commission in accordance with such regulations as it may prescribe; and provided, further, that the commission may waive the provisions of this section for the purpose of inspection or test flights of a non-passenger carrying aircraft.