14 Cfr 77

14 CFR Part 77 (up to date as of 11/15/2022)
Safe, Efficient Use, and Preservation of the Navigable Airspace

14 CFR Part 77

This content is from the eCFR and is authoritative but unofficial.

Title 14 - Aeronautics and Space
Chapter I - Federal Aviation Administration, Department of Transportation
Subchapter E - Airspace

Part 77 Safe, Efficient Use, and Preservation of the Navigable Airspace
Subpart A General
§ 77.1 Purpose.
§ 77.3 Definitions.
Subpart B Notice Requirements
§ 77.5 Applicability.
§ 77.7 Form and time of notice.
§ 77.9 Construction or alteration requiring notice.
§ 77.11 Supplemental notice requirements.
Subpart C Standards for Determining Obstructions to Air Navigation or
Navigational Aids or Facilities
§ 77.13 Applicability.
§ 77.15 Scope.
§ 77.17 Obstruction standards.
§ 77.19 Civil airport imaginary surfaces.
§ 77.21 Department of Defense (DOD) airport imaginary surfaces.
§ 77.23 Heliport imaginary surfaces.
Subpart D Aeronautical Studies and Determinations
§ 77.25 Applicability.
§ 77.27 Initiation of studies.
§ 77.29 Evaluating aeronautical effect.
§ 77.31 Determinations.
§ 77.33 Effective period of determinations.
§ 77.35 Extensions, terminations, revisions and corrections.
Subpart E Petitions for Discretionary Review
§ 77.37 General.
§ 77.39 Contents of a petition.
§ 77.41 Discretionary review results.

14 CFR Part 77 (enhanced display)

page 1 of 13

14 CFR Part 77 (up to date as of 11/15/2022)
Safe, Efficient Use, and Preservation of the Navigable Airspace

14 CFR 77

PART 77 - SAFE, EFFICIENT USE, AND PRESERVATION OF THE
NAVIGABLE AIRSPACE
Authority: 49 U.S.C. 106 (g), 40103, 40113-40114, 44502, 44701, 44718, 46101-46102, 46104.
Source: Docket No. FAA-2006-25002, 75 FR 42303, July 21, 2010, unless otherwise noted.

Subpart A - General
§ 77.1 Purpose.
This part establishes:
(a) The requirements to provide notice to the FAA of certain proposed construction, or the alteration of
existing structures;
(b) The standards used to determine obstructions to air navigation, and navigational and communication
facilities;
(c) The process for aeronautical studies of obstructions to air navigation or navigational facilities to
determine the effect on the safe and efficient use of navigable airspace, air navigation facilities or
equipment; and
(d) The process to petition the FAA for discretionary review of determinations, revisions, and extensions of
determinations.

§ 77.3 Definitions.
For the purpose of this part:
Non-precision instrument runway means a runway having an existing instrument approach procedure utilizing air
navigation facilities with only horizontal guidance, or area type navigation equipment, for which a straightin non-precision instrument approach procedure has been approved, or planned, and for which no
precision approach facilities are planned, or indicated on an FAA planning document or military service
military airport planning document.
Planned or proposed airport is an airport that is the subject of at least one of the following documents received
by the FAA:
(1) Airport proposals submitted under 14 CFR part 157.
(2) Airport Improvement Program requests for aid.
(3) Notices of existing airports where prior notice of the airport construction or alteration was not
provided as required by 14 CFR part 157.
(4) Airport layout plans.
(5) DOD proposals for airports used only by the U.S. Armed Forces.
(6) DOD proposals on joint-use (civil-military) airports.
(7) Completed airport site selection feasibility study.
14 CFR 77.3 “Planned or proposed airport” (7) (enhanced display)

page 2 of 13

14 CFR Part 77 (up to date as of 11/15/2022)
Safe, Efficient Use, and Preservation of the Navigable Airspace

14 CFR 77.3 “Precision instrument runway”

Precision instrument runway means a runway having an existing instrument approach procedure utilizing an
Instrument Landing System (ILS), or a Precision Approach Radar (PAR). It also means a runway for which
a precision approach system is planned and is so indicated by an FAA-approved airport layout plan; a
military service approved military airport layout plan; any other FAA planning document, or military service
military airport planning document.
Public use airport is an airport available for use by the general public without a requirement for prior approval of
the airport owner or operator.
Seaplane base is considered to be an airport only if its sea lanes are outlined by visual markers.
Utility runway means a runway that is constructed for and intended to be used by propeller driven aircraft of
12,500 pounds maximum gross weight and less.
Visual runway means a runway intended solely for the operation of aircraft using visual approach procedures,
with no straight-in instrument approach procedure and no instrument designation indicated on an FAAapproved airport layout plan, a military service approved military airport layout plan, or by any planning
document submitted to the FAA by competent authority.

Subpart B - Notice Requirements
§ 77.5 Applicability.
(a) If you propose any construction or alteration described in § 77.9, you must provide adequate notice to the
FAA of that construction or alteration.
(b) If requested by the FAA, you must also file supplemental notice before the start date and upon completion
of certain construction or alterations that are described in § 77.9.
(c) Notice received by the FAA under this subpart is used to:
(1) Evaluate the effect of the proposed construction or alteration on safety in air commerce and the
efficient use and preservation of the navigable airspace and of airport traffic capacity at public use
airports;
(2) Determine whether the effect of proposed construction or alteration is a hazard to air navigation;
(3) Determine appropriate marking and lighting recommendations, using FAA Advisory Circular 70/
7460-1, Obstruction Marking and Lighting;
(4) Determine other appropriate measures to be applied for continued safety of air navigation; and
(5) Notify the aviation community of the construction or alteration of objects that affect the navigable
airspace, including the revision of charts, when necessary.

§ 77.7 Form and time of notice.
(a) If you are required to file notice under § 77.9, you must submit to the FAA a completed FAA Form 7460-1,
Notice of Proposed Construction or Alteration. FAA Form 7460-1 is available at FAA regional offices and
on the Internet.
(b) You must submit this form at least 45 days before the start date of the proposed construction or
alteration or the date an application for a construction permit is filed, whichever is earliest.

14 CFR 77.7(b) (enhanced display)

page 3 of 13

14 CFR Part 77 (up to date as of 11/15/2022)
Safe, Efficient Use, and Preservation of the Navigable Airspace

14 CFR 77.7(c)

(c) If you propose construction or alteration that is also subject to the licensing requirements of the Federal
Communications Commission (FCC), you must submit notice to the FAA on or before the date that the
application is filed with the FCC.
(d) If you propose construction or alteration to an existing structure that exceeds 2,000 ft. in height above
ground level (AGL), the FAA presumes it to be a hazard to air navigation that results in an inefficient use of
airspace. You must include details explaining both why the proposal would not constitute a hazard to air
navigation and why it would not cause an inefficient use of airspace.
(e) The 45-day advance notice requirement is waived if immediate construction or alteration is required
because of an emergency involving essential public services, public health, or public safety. You may
provide notice to the FAA by any available, expeditious means. You must file a completed FAA Form
7460-1 within 5 days of the initial notice to the FAA. Outside normal business hours, the nearest flight
service station will accept emergency notices.

§ 77.9 Construction or alteration requiring notice.
If requested by the FAA, or if you propose any of the following types of construction or alteration, you must file
notice with the FAA of:
(a) Any construction or alteration that is more than 200 ft. AGL at its site.
(b) Any construction or alteration that exceeds an imaginary surface extending outward and upward at any of
the following slopes:
(1) 100 to 1 for a horizontal distance of 20,000 ft. from the nearest point of the nearest runway of each
airport described in paragraph (d) of this section with its longest runway more than 3,200 ft. in actual
length, excluding heliports.
(2) 50 to 1 for a horizontal distance of 10,000 ft. from the nearest point of the nearest runway of each
airport described in paragraph (d) of this section with its longest runway no more than 3,200 ft. in
actual length, excluding heliports.
(3) 25 to 1 for a horizontal distance of 5,000 ft. from the nearest point of the nearest landing and takeoff
area of each heliport described in paragraph (d) of this section.
(c) 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) or (b) of this section.
(d) Any construction or alteration on any of the following airports and heliports:
(1) A public use airport listed in the Airport/Facility Directory, Alaska Supplement, or Pacific Chart
Supplement of the U.S. Government Flight Information Publications;
(2) A military airport under construction, or an airport under construction that will be available for public
use;
(3) An airport operated by a Federal agency or the DOD.
(4) An airport or heliport with at least one FAA-approved instrument approach procedure.
14 CFR 77.9(d)(4) (enhanced display)

page 4 of 13

14 CFR Part 77 (up to date as of 11/15/2022)
Safe, Efficient Use, and Preservation of the Navigable Airspace

14 CFR 77.9(e)

(e) You do not need to file notice for construction or alteration of:
(1) Any object that will be shielded by existing structures of a permanent and substantial nature or by
natural terrain or topographic features of equal or greater height, and will be located in the congested
area of a city, town, or settlement where the shielded structure will not adversely affect safety in air
navigation;
(2) Any air navigation facility, airport visual approach or landing aid, aircraft arresting device, or
meteorological device meeting FAA-approved siting criteria or an appropriate military service siting
criteria on military airports, the location and height of which are fixed by its functional purpose;
(3) Any construction or alteration for which notice is required by any other FAA regulation.
(4) Any antenna structure of 20 feet or less in height, except one that would increase the height of
another antenna structure.

§ 77.11 Supplemental notice requirements.
(a) You must file supplemental notice with the FAA when:
(1) The construction or alteration is more than 200 feet in height AGL at its site; or
(2) Requested by the FAA.
(b) You must file supplemental notice on a prescribed FAA form to be received within the time limits specified
in the FAA determination. If no time limit has been specified, you must submit supplemental notice of
construction to the FAA within 5 days after the structure reaches its greatest height.
(c) If you abandon a construction or alteration proposal that requires supplemental notice, you must submit
notice to the FAA within 5 days after the project is abandoned.
(d) If the construction or alteration is dismantled or destroyed, you must submit notice to the FAA within 5
days after the construction or alteration is dismantled or destroyed.

Subpart C - Standards for Determining Obstructions to Air Navigation or Navigational Aids or
Facilities
§ 77.13 Applicability.
This subpart describes the standards used for determining obstructions to air navigation, navigational aids, or
navigational facilities. These standards apply to the following:
(a) Any object of natural growth, terrain, or permanent or temporary construction or alteration, including
equipment or materials used and any permanent or temporary apparatus.
(b) The alteration of any permanent or temporary existing structure by a change in its height, including
appurtenances, or lateral dimensions, including equipment or material used therein.

§ 77.15 Scope.
(a) This subpart describes standards used to determine obstructions to air navigation that may affect the
safe and efficient use of navigable airspace and the operation of planned or existing air navigation and
communication facilities. Such facilities include air navigation aids, communication equipment, airports,
Federal airways, instrument approach or departure procedures, and approved off-airway routes.
14 CFR 77.15(a) (enhanced display)

page 5 of 13

14 CFR Part 77 (up to date as of 11/15/2022)
Safe, Efficient Use, and Preservation of the Navigable Airspace

14 CFR 77.15(b)

(b) Objects that are considered obstructions under the standards described in this subpart are presumed
hazards to air navigation unless further aeronautical study concludes that the object is not a hazard. Once
further aeronautical study has been initiated, the FAA will use the standards in this subpart, along with
FAA policy and guidance material, to determine if the object is a hazard to air navigation.
(c) The FAA will apply these standards with reference to an existing airport facility, and airport proposals
received by the FAA, or the appropriate military service, before it issues a final determination.
(d) For airports having defined runways with specially prepared hard surfaces, the primary surface for each
runway extends 200 feet beyond each end of the runway. For airports having defined strips or pathways
used regularly for aircraft takeoffs and landings, and designated runways, without specially prepared hard
surfaces, each end of the primary surface for each such runway shall coincide with the corresponding end
of the runway. At airports, excluding seaplane bases, having a defined landing and takeoff area with no
defined pathways for aircraft takeoffs and landings, a determination must be made as to which portions
of the landing and takeoff area are regularly used as landing and takeoff pathways. Those determined
pathways must be considered runways, and an appropriate primary surface as defined in § 77.19 will be
considered as longitudinally centered on each such runway. Each end of that primary surface must
coincide with the corresponding end of that runway.
(e) The standards in this subpart apply to construction or alteration proposals on an airport (including
heliports and seaplane bases with marked lanes) if that airport is one of the following before the issuance
of the final determination:
(1) Available for public use and is listed in the Airport/Facility Directory, Supplement Alaska, or
Supplement Pacific of the U.S. Government Flight Information Publications; or
(2) A planned or proposed airport or an airport under construction of which the FAA has received actual
notice, except DOD airports, where there is a clear indication the airport will be available for public
use; or,
(3) An airport operated by a Federal agency or the DOD; or,
(4) An airport that has at least one FAA-approved instrument approach.

§ 77.17 Obstruction standards.
(a) An existing object, including a mobile object, is, and a future object would be an obstruction to air
navigation if it is of greater height than any of the following heights or surfaces:
(1) A height of 499 feet AGL at the site of the object.
(2) A height that is 200 feet AGL, or above the established airport elevation, whichever is higher, within 3
nautical miles of the established reference point of an airport, excluding heliports, with its longest
runway more than 3,200 feet in actual length, and that height increases in the proportion of 100 feet
for each additional nautical mile from the airport up to a maximum of 499 feet.
(3) A height within a terminal obstacle clearance area, including an initial approach segment, a
departure area, and a circling approach area, which would result in the vertical distance between any
point on the object and an established minimum instrument flight altitude within that area or
segment to be less than the required obstacle clearance.
(4) A height within an en route obstacle clearance area, including turn and termination areas, of a
Federal Airway or approved off-airway route, that would increase the minimum obstacle clearance
altitude.
14 CFR 77.17(a)(4) (enhanced display)

page 6 of 13

14 CFR Part 77 (up to date as of 11/15/2022)
Safe, Efficient Use, and Preservation of the Navigable Airspace

14 CFR 77.17(a)(5)

(5) The surface of a takeoff and landing area of an airport or any imaginary surface established under §
77.19, 77.21, or 77.23. However, no part of the takeoff or landing area itself will be considered an
obstruction.
(b) Except for traverse ways on or near an airport with an operative ground traffic control service furnished by
an airport traffic control tower or by the airport management and coordinated with the air traffic control
service, the standards of paragraph (a) of this section apply to traverse ways used or to be used for the
passage of mobile objects only after the heights of these traverse ways are increased by:
(1) 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.
(2) 15 feet for any other public roadway.
(3) 10 feet or the height of the highest mobile object that would normally traverse the road, whichever is
greater, for a private road.
(4) 23 feet for a railroad.
(5) 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.

§ 77.19 Civil airport imaginary surfaces.
The following civil airport imaginary surfaces are established with relation to the airport and to each runway. The
size of each such imaginary surface is based on the category of each runway according to the type of approach
available or planned for that runway. The slope and dimensions of the approach surface applied to each end of a
runway are determined by the most precise approach procedure existing or planned for that runway end.
(a) Horizontal surface. A horizontal plane 150 feet above the established airport elevation, the perimeter of
which is constructed by swinging arcs of a specified radii from the center of each end of the primary
surface of each runway of each airport and connecting the adjacent arcs by lines tangent to those arcs.
The radius of each arc is:
(1) 5,000 feet for all runways designated as utility or visual;
(2) 10,000 feet for all other runways. The radius of the arc specified for each end of a runway will have
the same arithmetical value. That value will be the highest determined for either end of the runway.
When a 5,000-foot arc is encompassed by tangents connecting two adjacent 10,000-foot arcs, the
5,000-foot arc shall be disregarded on the construction of the perimeter of the horizontal surface.
(b) Conical surface. A surface extending outward and upward from the periphery of the horizontal surface at
a slope of 20 to 1 for a horizontal distance of 4,000 feet.
(c) Primary surface. A surface longitudinally centered on a runway. When the runway has a specially prepared
hard surface, the primary surface extends 200 feet beyond each end of that runway; but when the runway
has no specially prepared hard surface, the primary surface ends at each end of that runway. The
elevation of any point on the primary surface is the same as the elevation of the nearest point on the
runway centerline. The width of the primary surface is:
(1) 250 feet for utility runways having only visual approaches.
(2) 500 feet for utility runways having non-precision instrument approaches.
(3) For other than utility runways, the width is:
14 CFR 77.19(c)(3) (enhanced display)

page 7 of 13

14 CFR Part 77 (up to date as of 11/15/2022)
Safe, Efficient Use, and Preservation of the Navigable Airspace

(i)

14 CFR 77.19(c)(3)(i)

500 feet for visual runways having only visual approaches.

(ii) 500 feet for non-precision instrument runways having visibility minimums greater than threefourths statute mile.
(iii) 1,000 feet for a non-precision instrument runway having a non-precision instrument approach
with visibility minimums as low as three-fourths of a statute mile, and for precision instrument
runways.
(iv) The width of the primary surface of a runway will be that width prescribed in this section for the
most precise approach existing or planned for either end of that runway.
(d) Approach surface. A surface longitudinally centered on the extended runway centerline and extending
outward and upward from each end of the primary surface. An approach surface is applied to each end of
each runway based upon the type of approach available or planned for that runway end.
(1) The inner edge of the approach surface is the same width as the primary surface and it expands
uniformly to a width of:
(i)

1,250 feet for that end of a utility runway with only visual approaches;

(ii) 1,500 feet for that end of a runway other than a utility runway with only visual approaches;
(iii) 2,000 feet for that end of a utility runway with a non-precision instrument approach;
(iv) 3,500 feet for that end of a non-precision instrument runway other than utility, having visibility
minimums greater that three-fourths of a statute mile;
(v) 4,000 feet for that end of a non-precision instrument runway, other than utility, having a nonprecision instrument approach with visibility minimums as low as three-fourths statute mile;
and
(vi) 16,000 feet for precision instrument runways.
(2) The approach surface extends for a horizontal distance of:
(i)

5,000 feet at a slope of 20 to 1 for all utility and visual runways;

(ii) 10,000 feet at a slope of 34 to 1 for all non-precision instrument runways other than utility; and
(iii) 10,000 feet at a slope of 50 to 1 with an additional 40,000 feet at a slope of 40 to 1 for all
precision instrument runways.
(3) The outer width of an approach surface to an end of a runway will be that width prescribed in this
subsection for the most precise approach existing or planned for that runway end.
(e) Transitional surface. These surfaces extend outward and upward at right angles to the runway centerline
and the runway centerline extended at a slope of 7 to 1 from the sides of the primary surface and from the
sides of the approach surfaces. Transitional surfaces for those portions of the precision approach
surface which project through and beyond the limits of the conical surface, extend a distance of 5,000
feet measured horizontally from the edge of the approach surface and at right angles to the runway
centerline.

§ 77.21 Department of Defense (DOD) airport imaginary surfaces.
(a) Related to airport reference points. These surfaces apply to all military airports. For the purposes of this
section, a military airport is any airport operated by the DOD.
14 CFR 77.21(a) (enhanced display)

page 8 of 13

14 CFR Part 77 (up to date as of 11/15/2022)
Safe, Efficient Use, and Preservation of the Navigable Airspace

14 CFR 77.21(a)(1)

(1) Inner horizontal surface. A plane that is oval in shape at a height of 150 feet above the established
airfield elevation. The plane is constructed by scribing an arc with a radius of 7,500 feet about the
centerline at the end of each runway and interconnecting these arcs with tangents.
(2) Conical surface. A surface extending from the periphery of the inner horizontal surface outward and
upward at a slope of 20 to 1 for a horizontal distance of 7,000 feet to a height of 500 feet above the
established airfield elevation.
(3) Outer horizontal surface. A plane, located 500 feet above the established airfield elevation, extending
outward from the outer periphery of the conical surface for a horizontal distance of 30,000 feet.
(b) Related to runways. These surfaces apply to all military airports.
(1) Primary surface. A surface located on the ground or water longitudinally centered on each runway
with the same length as the runway. The width of the primary surface for runways is 2,000 feet.
However, at established bases where substantial construction has taken place in accordance with a
previous lateral clearance criteria, the 2,000-foot width may be reduced to the former criteria.
(2) Clear zone surface. A surface located on the ground or water at each end of the primary surface,
with a length of 1,000 feet and the same width as the primary surface.
(3) Approach clearance surface. An inclined plane, symmetrical about the runway centerline extended,
beginning 200 feet beyond each end of the primary surface at the centerline elevation of the runway
end and extending for 50,000 feet. The slope of the approach clearance surface is 50 to 1 along the
runway centerline extended until it reaches an elevation of 500 feet above the established airport
elevation. It then continues horizontally at this elevation to a point 50,000 feet from the point of
beginning. The width of this surface at the runway end is the same as the primary surface, it flares
uniformly, and the width at 50,000 is 16,000 feet.
(4) Transitional surfaces. These surfaces connect the primary surfaces, the first 200 feet of the clear
zone surfaces, and the approach clearance surfaces to the inner horizontal surface, conical surface,
outer horizontal surface or other transitional surfaces. The slope of the transitional surface is 7 to 1
outward and upward at right angles to the runway centerline.

§ 77.23 Heliport imaginary surfaces.
(a) Primary surface. The area of the primary surface coincides in size and shape with the designated take-off
and landing area. This surface is a horizontal plane at the elevation of the established heliport elevation.
(b) Approach surface. The approach surface begins at each end of the heliport primary surface with the same
width as the primary surface, and extends outward and upward for a horizontal distance of 4,000 feet
where its width is 500 feet. The slope of the approach surface is 8 to 1 for civil heliports and 10 to 1 for
military heliports.
(c) Transitional surfaces. These surfaces extend outward and upward from the lateral boundaries of the
primary surface and from the approach surfaces at a slope of 2 to 1 for a distance of 250 feet measured
horizontally from the centerline of the primary and approach surfaces.

Subpart D - Aeronautical Studies and Determinations
§ 77.25 Applicability.
(a) This subpart applies to any aeronautical study of a proposed construction or alteration for which notice to
the FAA is required under § 77.9.
14 CFR 77.25(a) (enhanced display)

page 9 of 13

14 CFR Part 77 (up to date as of 11/15/2022)
Safe, Efficient Use, and Preservation of the Navigable Airspace

14 CFR 77.25(b)

(b) The purpose of an aeronautical study is to determine whether the aeronautical effects of the specific
proposal and, where appropriate, the cumulative impact resulting from the proposed construction or
alteration when combined with the effects of other existing or proposed structures, would constitute a
hazard to air navigation.
(c) The obstruction standards in subpart C of this part are supplemented by other manuals and directives
used in determining the effect on the navigable airspace of a proposed construction or alteration. When
the FAA needs additional information, it may circulate a study to interested parties for comment.

§ 77.27 Initiation of studies.
The FAA will conduct an aeronautical study when:
(a) Requested by the sponsor of any proposed construction or alteration for which a notice is submitted; or
(b) The FAA determines a study is necessary.

§ 77.29 Evaluating aeronautical effect.
(a) The FAA conducts an aeronautical study to determine the impact of a proposed structure, an existing
structure that has not yet been studied by the FAA, or an alteration of an existing structure on aeronautical
operations, procedures, and the safety of flight. These studies include evaluating:
(1) The impact on arrival, departure, and en route procedures for aircraft operating under visual flight
rules;
(2) The impact on arrival, departure, and en route procedures for aircraft operating under instrument
flight rules;
(3) The impact on existing and planned public use airports;
(4) Airport traffic capacity of existing public use airports and public use airport development plans
received before the issuance of the final determination;
(5) Minimum obstacle clearance altitudes, minimum instrument flight rules altitudes, approved or
planned instrument approach procedures, and departure procedures;
(6) The potential effect on ATC radar, direction finders, ATC tower line-of-sight visibility, and physical or
electromagnetic effects on air navigation, communication facilities, and other surveillance systems;
(7) The aeronautical effects resulting from the cumulative impact of a proposed construction or
alteration of a structure when combined with the effects of other existing or proposed structures.
(b) If you withdraw the proposed construction or alteration or revise it so that it is no longer identified as an
obstruction, or if no further aeronautical study is necessary, the FAA may terminate the study.

§ 77.31 Determinations.
(a) The FAA will issue a determination stating whether the proposed construction or alteration would be a
hazard to air navigation, and will advise all known interested persons.
(b) The FAA will make determinations based on the aeronautical study findings and will identify the following:
(1) The effects on VFR/IFR aeronautical departure/arrival operations, air traffic procedures, minimum
flight altitudes, and existing, planned, or proposed airports listed in § 77.15(e) of which the FAA has
received actual notice prior to issuance of a final determination.
14 CFR 77.31(b)(1) (enhanced display)

page 10 of 13

14 CFR Part 77 (up to date as of 11/15/2022)
Safe, Efficient Use, and Preservation of the Navigable Airspace

14 CFR 77.31(b)(2)

(2) The extent of the physical and/or electromagnetic effect on the operation of existing or proposed air
navigation facilities, communication aids, or surveillance systems.
(c) The FAA will issue a Determination of Hazard to Air Navigation when the aeronautical study concludes
that the proposed construction or alteration will exceed an obstruction standard and would have a
substantial aeronautical impact.
(d) A Determination of No Hazard to Air Navigation will be issued when the aeronautical study concludes that
the proposed construction or alteration will exceed an obstruction standard but would not have a
substantial aeronautical impact to air navigation. A Determination of No Hazard to Air Navigation may
include the following:
(1) Conditional provisions of a determination.
(2) Limitations necessary to minimize potential problems, such as the use of temporary construction
equipment.
(3) Supplemental notice requirements, when required.
(4) Marking and lighting recommendations, as appropriate.
(e) The FAA will issue a Determination of No Hazard to Air Navigation when a proposed structure does not
exceed any of the obstruction standards and would not be a hazard to air navigation.

§ 77.33 Effective period of determinations.
(a) The effective date of a determination not subject to discretionary review under 77.37(b) is the date of
issuance. The effective date of all other determinations for a proposed or existing structure is 40 days
from the date of issuance, provided a valid petition for review has not been received by the FAA. If a valid
petition for review is filed, the determination will not become final, pending disposition of the petition.
(b) Unless extended, revised, or terminated, each Determination of No Hazard to Air Navigation issued under
this subpart expires 18 months after the effective date of the determination, or on the date the proposed
construction or alteration is abandoned, whichever is earlier.
(c) A Determination of Hazard to Air Navigation has no expiration date.
[Doc. No. FAA-2006-25002, 75 FR 42303, July 21, 2010, as amended by Amdt. 77-13-A, 76 FR 2802, Jan. 18, 2011]

§ 77.35 Extensions, terminations, revisions and corrections.
(a) You may petition the FAA official that issued the Determination of No Hazard to Air Navigation to revise or
reconsider the determination based on new facts or to extend the effective period of the determination,
provided that:
(1) Actual structural work of the proposed construction or alteration, such as the laying of a foundation,
but not including excavation, has not been started; and
(2) The petition is submitted at least 15 days before the expiration date of the Determination of No
Hazard to Air Navigation.
(b) A Determination of No Hazard to Air Navigation issued for those construction or alteration proposals not
requiring an FCC construction permit may be extended by the FAA one time for a period not to exceed 18
months.
14 CFR 77.35(b) (enhanced display)

page 11 of 13

14 CFR Part 77 (up to date as of 11/15/2022)
Safe, Efficient Use, and Preservation of the Navigable Airspace

14 CFR 77.35(c)

(c) A Determination of No Hazard to Air Navigation issued for a proposal requiring an FCC construction
permit may be granted extensions for up to 18 months, provided that:
(1) You submit evidence that an application for a construction permit/license was filed with the FCC for
the associated site within 6 months of issuance of the determination; and
(2) You submit evidence that additional time is warranted because of FCC requirements; and
(3) Where the FCC issues a construction permit, a final Determination of No Hazard to Air Navigation is
effective until the date prescribed by the FCC for completion of the construction. If an extension of
the original FCC completion date is needed, an extension of the FAA determination must be
requested from the Obstruction Evaluation Service (OES).
(4) If the Commission refuses to issue a construction permit, the final determination expires on the date
of its refusal.

Subpart E - Petitions for Discretionary Review
§ 77.37 General.
(a) If you are the sponsor, provided a substantive aeronautical comment on a proposal in an aeronautical
study, or have a substantive aeronautical comment on the proposal but were not given an opportunity to
state it, you may petition the FAA for a discretionary review of a determination, revision, or extension of a
determination issued by the FAA.
(b) You may not file a petition for discretionary review for a Determination of No Hazard that is issued for a
temporary structure, marking and lighting recommendation, or when a proposed structure or alteration
does not exceed obstruction standards contained in subpart C of this part.

§ 77.39 Contents of a petition.
(a) You must file a petition for discretionary review in writing and it must be received by the FAA within 30
days after the issuance of a determination under § 77.31, or a revision or extension of the determination
under § 77.35.
(b) The petition must contain a full statement of the aeronautical basis on which the petition is made, and
must include new information or facts not previously considered or presented during the aeronautical
study, including valid aeronautical reasons why the determination, revisions, or extension made by the
FAA should be reviewed.
(c) In the event that the last day of the 30-day filing period falls on a weekend or a day the Federal
government is closed, the last day of the filing period is the next day that the government is open.
(d) The FAA will inform the petitioner or sponsor (if other than the petitioner) and the FCC (whenever an FCCrelated proposal is involved) of the filing of the petition and that the determination is not final pending
disposition of the petition.

§ 77.41 Discretionary review results.
(a) If discretionary review is granted, the FAA will inform the petitioner and the sponsor (if other than the
petitioner) of the issues to be studied and reviewed. The review may include a request for comments and
a review of all records from the initial aeronautical study.

14 CFR 77.41(a) (enhanced display)

page 12 of 13

14 CFR Part 77 (up to date as of 11/15/2022)
Safe, Efficient Use, and Preservation of the Navigable Airspace

14 CFR 77.41(b)

(b) If discretionary review is denied, the FAA will notify the petitioner and the sponsor (if other than the
petitioner), and the FCC, whenever a FCC-related proposal is involved, of the basis for the denial along
with a statement that the determination is final.
(c) After concluding the discretionary review process, the FAA will revise, affirm, or reverse the determination.

14 CFR 77.41(c) (enhanced display)

page 13 of 13