§ 247. Examination of wrecked aircraft before destruction or removal. When an aircraft falls or lands in a wrecked condition or is wrecked by the fall or in landing and an occupant thereof is killed or severely injured thereby or escapes death or injury by the use of a parachute, neither such aircraft nor any part of it shall be destroyed or removed before the expiration of twenty-four hours thereafter without the permission of an inspector of the federal aviation agency or an investigator of the civil aeronautics board or a member of the state police or of a sheriff or regular deputy sheriff; and if, before it is destroyed or removed, such an inspector or member of the state police or sheriff or deputy sheriff shall appear at the scene of the wreck for the purpose of examining the aircraft it shall not be destroyed or removed until the examination is completed provided the examination be completed within forty-eight hours of the time that the aircraft fell or landed. This section shall not prevent or postpone the destruction or removal of a wrecked aircraft lying in a public street or highway in a position that causes a blockade of traffic, or lying in a navigable waterway in a position that impedes or imperils navigation, or which lands or falls on a building or structure, or in a case where the immediate destruction or removal of the aircraft is necessary to prevent injury to persons; but such necessity in the case last mentioned, shall be a matter of defense in any prosecution for a violation of this section. A person who destroys or removes, or causes to be destroyed or removed, a wrecked aircraft in violation of the provisions of this section is guilty of a misdemeanor.