Section 331.14 - Aircraft(a) The operation of aircraft on WCA lands and waters is prohibited, unless authorized in writing by the District Engineer.(b) Except in extreme emergencies threatening human life or serious property loss, the air delivery of any person or thing by parachute, helicopter, or other means onto project lands or waters without written permission of the District Engineer is prohibited.(c) The provisions of this section shall not be applicable to aircraft engaged on official business of the Federal Government or used in emergency rescue in accordance with the directions of the District Engineer.