(a) Except as provided in §77.15, each sponsor who proposes any of the
following construction or alteration shall notify the Administrator in the
form and manner prescribed in §77.17:
(1) Any construction or alteration of more than 200 feet in height
above the ground level at its site.
(2) Any construction or alteration of greater height than an imaginary
surface extending outward and upward at one of the following slopes:
(i) 100 to 1 for a horizontal distance of 20,000 feet from the nearest
point of the nearest runway of each airport specified in paragraph (a)(5)
of this section with at least one runway more than 3,200 feet in actual
length, excluding heliports.
(ii) 50 to 1 for a horizontal distance of 10,000 feet from the nearest
point of the nearest runway of each airport specified in paragraph (a)(5)
of this section with its longest runway no more than 3,200 feet in actual
length, excluding heliports.
(iii) 25 to 1 for a horizontal distance of 5,000 feet from the nearest
point of the nearest landing and takeoff area of each heliport specified
in paragraph (a)(5) of this section.
(3) Any highway, railroad, or other traverse way for mobile objects, of
a height which, if adjusted upward 17 feet for an Interstate Highway that
is part of the National System of Military and Interstate Highways where
overcrossings are designed for a minimum of 17 feet vertical distance, 15
feet for any other public roadway, 10 feet or the height of the highest
mobile object that would normally traverse the road, whichever is greater,
for a private road, 23 feet for a railroad, and for a waterway or any
other traverse way not previously mentioned, an amount equal to the height
of the highest mobile object that would normally traverse it, would exceed
a standard of paragraph (a) (1) or (2) of this section.
(4) When requested by the FAA, any construction or alteration that
would be in an instrument approach area (defined in the FAA standards
governing instrument approach procedures) and available information
indicates it might exceed a standard of subpart C of this part.
(5) Any construction or alteration on any of the following airports
(including heliports):
(i) An airport that is available for public use and is listed in the
Airport Directory of the current Airman's Information Manual or in either
the Alaska or Pacific Airman's Guide and Chart Supplement.
(ii) An airport under construction, that is the subject of a notice or
proposal on file with the Federal Aviation Administration, and, except for
military airports, it is clearly indicated that that airport will be
available for public use.
(iii) An airport that is operated by an armed force of the United
States.
(b) Each sponsor who proposes construction or alteration that is the
subject of a notice under paragraph (a) of this section and is advised by
an FAA regional office that a supplemental notice is required shall submit
that notice on a prescribed form to be received by the FAA regional office
at least 48 hours before the start of the construction or alteration.
(c) Each sponsor who undertakes construction or alteration that is the
subject of a notice under paragraph (a) of this section shall, within 5
days after that construction or alteration reaches its greatest height,
submit a supplemental notice on a prescribed form to the FAA regional
office having jurisdiction over the region involved, if --
(1) The construction or alteration is more than 200 feet above the
surface level of its site; or
(2) An FAA regional office advises him that submission of the form is
required.