(1) Except when necessary for taking off, or landing, or except with prior written approval of the Director, no aircraft—
(a) shall be flown over congested areas or over an obvious open-air assembly of persons at a height less than 1 000 ft above the highest obstacle, within a radius of 2 000 ft from the aircraft;
(b) when flown elsewhere than specified in paragraph (a), shall be flown at a height less than 500 ft above the ground or water, unless the flight can be made without hazard or nuisance to persons or property on the ground or water and the PIC operates at a height and in a manner that allows safe operation in the event of an engine failure; and
(c) shall circle over or do repeated overflights over an obvious open-air assembly of persons at a height less than 3 000 ft above the surface.
(2) *(For helicopters only)
(3) Except when necessary for take-off or landing, or with the express permission of the Director, an aircraft shall at night, in IMC or when operated in accordance with IFR, be flown—
(a) at a height of at least 1 000 ft above the highest terrain or obstacle where the height of such terrain or obstacle does not exceed 5 000 ft above sea level within 5 NM of the aircraft in flight; or
(b) at a height of at least 2 000 ft above the highest terrain or obstacle located within 5 NM of the aircraft in flight where the height of such terrain or obstacle exceeds 5 000 ft above sea level: Provided that within areas determined by the Director the minimum height may be reduced to 1 000 ft above the highest terrain or obstacle located within 5 NM of the aircraft in flight, and the aircraft is flown in accordance with such procedures as the Director may determine.
(4) The PIC of an aircraft shall, in addition to the requirements of this regulation, comply with any altitude restrictions prescribed for the area or route to be operated within or over.