Document
SUBCHAPTER J—NAVIGATIONAL FACILITIES
Air traffic controller means a person PART 170—ESTABLISHMENT AND authorized to provide air traffic serv- DISCONTINUANCE CRITERIA FOR ice, specifically en route and terminal AIR TRAFFIC CONTROL SERVICES control personnel.
AND NAVIGATIONAL FACILITIES Aircraft operations means the airborne movement of aircraft in controlled or Subpart A—General noncontrolled airport terminal areas, and counts at en route fixes or other Sec.
170.1 Scope. points where counts can be made.
170.3 Definitions.
There are two types of operations: local and itinerant.
Subpart B—Airport Traffic Control Towers (1) Local operations mean operations performed by aircraft which: 170.11 Scope.
170.13 Airport Traffic Control Tower (ATCT) (i) Operate in the local traffic pat- establishment criteria.
tern or within sight of the airport; 170.15 ATCT discontinuance criteria.
(ii) Are known to be departing for, or arriving from flight in local practice Subpart C [ Reserved ] areas located within a 20-mile radius of the airport; or A UTHORITY : 49 U.S.C. 106(g), 40103–40107, (iii) Execute simulated instrument 40113, 44502, 44701–44702, 44708–44709, 44719, approaches or low passes at the air- 44721–44722, 46308.
port.
S OURCE : 56 FR 341, Jan. 3, 1991, unless oth- (2) Itinerant operations mean all air- erwise noted.
craft operations other than local oper- ations.
Subpart A—General Airport traffic control tower means a terminal facility, which through the § 170.1 Scope.
use of air/ground communications, vis- This subpart sets forth establishment ual signaling, and other devices, pro- and discontinuance criteria for naviga- vides ATC services to airborne aircraft tion aids operated and maintained by operating in the vicinity of an airport the United States.
and to aircraft operating on the airport area.
§ 170.3 Definitions.
Alternate airport means an airport, For purposes of this subpart— specified on a flight plan, to which a Air navigation facility (NAVAID) flight may proceed when a landing at means any facility used, available for the point of first intended landing be- use, or designated for use in the aid of comes inadvisable.
air navigation. Included are landing Approach means the flight path es- areas; lights; signaling, radio direction- tablished by the FAA to be used by air- finding, or radio or other electronic craft landing on a runway.
communication; and any other struc- Approach control facility means a ter- ture or mechanism having a similar minal air traffic control facility pro- purpose of guiding or controlling flight viding approach control service.
or the landing or takeoff of aircraft. Arrival means any aircraft arriving at Air traffic clearance means an author- an airport.
ization by air traffic control for an air- Benefit-cost ratio means the quotient craft to proceed under specified traffic of the discounted life cycle benefits of conditions within controlled airspace an air traffic control service or naviga- for the purpose of preventing collision tion aid facility ( i.e. , ATCT) divided by between known aircraft. the discounted life cycle costs.
Air traffic control (ATC) means a serv- Ceiling means the vertical distance ice that promotes the safe, orderly, and between the ground or water and the expeditious flow of air traffic, includ- lowest layer of clouds or obscuring phe- ing airport, approach, departure, and nomena that is reported as ‘‘broken,’’ en route air traffic control. ‘‘overcast,’’ or ‘‘obstruction.’’ VerDate Sep<11>2014 10:01 Aug 27, 2026 Jkt 268049 PO 00000 Frm 00826 Fmt 8010 Sfmt 8010 Y:\SGML\268049.XXX 268049 jgilmore on DSK4WB1RN3PROD with CFR Federal Aviation Administration, DOT § 170.3 Control Tower —See Airport Traffic Mean sea level (MSL) means the base Control Tower. commonly used in measuring altitudes.
Criteria means the standards used by Microwave landing system (MLS) the FAA for the determination of es- means a landing system which enables tablishment or discontinuance of a equipped aircraft to make curved and service or facility at an airport. closely spaced approaches to properly Departure means any aircraft taking instrumented airports.
off from an airport. Noncommercial traffic means all air- Discontinuance means the withdrawal craft operations that are conducted of a service and/or facility from an air- free of compensation.
port. Nonprecision approach procedure Establishment means the provision of means an FAA standard for approach- a service or facility at a candidate air- ing an IFR runway where no electronic port. glide slope is available.
Instrument approach means a series of Nonscheduled commercial service means predetermined maneuvers for the or- the carriage by aircraft in air com- derly transfer of an aircraft under in- merce of persons or property for com- strument flight conditions from the be- pensation or hire that are not operated ginning of the initial approach to a in regularly scheduled service such as landing, or to a point from which a charter flights.
landing may be made visually. It is Present value (PV) means the value of prescribed and approved for a specific a stream of future benefits or costs airport by competent authority. that are discounted to the present.
Instrument flight rules (IFR) means PVB or BPV means the discounted rules governing the procedures for con- value of life cycle benefits.
ducting flight under instrument mete- PVC or CPV means the discounted orological conditions (IMC) instrument value of life cycle benefits.
flight. PVCM or CMPV means the dis- Instrument landing system (ILS) means counted value of operations and main- an instrument landing system whereby tenance costs less termination costs the pilot guides his approach to a run- over a facility’s remaining life cycle.
way solely by reference to instruments Runway means a defined rectangular in the cockpit. In some instances, the area on a land airport prepared for the signals received from the ground can be landing and takeoff of aircraft along fed into the automatic pilot for auto- its length.
matically controlled approaches. Runway visual range means an instru- Instrument meteorological conditions mentally derived value based on stand- (IMC) means weather conditions below ard calibrations that represent the hor- the minimums prescribed for flight izontal distance a pilot will see down under Visual Flight Rules (VFR). the runway from the approach end.
Instrument operation means an air- Scheduled commercial service means craft operation in accordance with an the carriage by aircraft in air com- IFT flight plan or an operation where merce under parts 121 and 135 of per- IFR separation between aircraft is pro- sons or property for compensation or vided by a terminal control facility or hire based on published flight sched- air route traffic control center ules.
(ARTCC). Separation means the spacing of air- Life cycle benefits means the value of craft in flight and while landing and services provided to aviation users over taking off to achieve their safe and or- the life span of a facility or service. derly movement.
Life cycle costs means the value of re- Takeoff clearance means authoriza- search and development costs, invest- tion by an airport traffic control tower ment costs, operation costs, mainte- for an aircraft to take off.
nance costs, and termination costs Tower cab means an ATC facility lo- over the life span of a facility or serv- cated at an airport. Controllers at ice. these facilities direct ground traffic, Maintenance costs means the costs in- takeoffs, and landings.
curred in servicing and maintaining a Traffic advisories means advisories facility after establishment. issued to alert pilots to other known or VerDate Sep<11>2014 10:01 Aug 27, 2026 Jkt 268049 PO 00000 Frm 00827 Fmt 8010 Sfmt 8010 Y:\SGML\268049.XXX 268049 jgilmore on DSK4WB1RN3PROD with CFR 14 CFR Ch. I (1–1–26 Edition) § 170.11 observed air traffic which may be in mit the amortization of the ATCT in- such proximity to the position or in- vestment; tended route of flight of their aircraft (4) The FAA must be furnished appro- to warrant attention.
priate land without cost for construc- Traffic pattern means the flow of air- tion of the ATCT; and craft operating on and in the vicinity (5) The airport must meet the ben- of an airport during specified wind con- efit-cost ratio criteria specified herein ditions as established by appropriate utilizing three consecutive FAA annual authority.
counts and projections of future traffic VFR traffic means aircraft operated during the expected life of the tower fa- solely in accordance with Visual Flight cility. (An FAA annual count is a fiscal Rules.
year or a calendar year activity sum- Visual flight rules (VFR) means rules mary. Where actual traffic counts are that govern the procedures for con- unavailable or not recorded, ade- ducting flight under visual conditions.
quately documented FAA estimates of The term ‘‘VFR’’ is also used in the the scheduled and nonscheduled activ- United States to indicate weather con- ity may be used.)
ditions that are equal to or greater (b) An airport meets the establish- than minimum VFR requirements. In ment criteria when it satisfies para- addition, ‘‘VFR’’ is used by pilots and graphs (a)(1) through (a)(5) of this sec- controllers to indicate the type of tion and its benefit-cost ratio equals or flight plan.
exceeds one. As defined in § 170.3 of this Visual meteorological conditions (VMC) part, the benefit-cost ratio is the ratio means meteorological conditions ex- of the present value of the ATCT life pressed in terms of visibility, distance cycle benefits (BPV) to the present from clouds, and ceiling equal to or value of ATCT life cycle costs (CPV).
better than specified minima.
BPV/CPV ≥ 1.0 [56 FR 341, Jan. 3, 1991, as amended by Amdt.
170–3, 66 FR 21067, Apr. 27, 2001; Docket FAA– (c) The satisfaction of all the criteria 2017–0733, Amdt. 170–4, 82 FR 34400, July 25, listed in this section does not guar- 2017] antee that the airport will receive an ATCT.
Subpart B—Airport Traffic Control Towers § 170.15 ATCT discontinuance criteria.
An ATCT will be subject to dis- § 170.11 Scope.
continuance when the continued oper- This subpart sets forth establishment ation and maintenance costs less ter- and discontinuance criteria for Airport mination costs (CMPV) of the ATCT Traffic Control Towers.
exceed the present value of its remain- ing life-cycle benefits (BPV): § 170.13 Airport Traffic Control Tower (ATCT) establishment criteria.
BPV/CMPV<1.0 (a) The following criteria along with general facility establishment stand- Subpart C [ Reserved ] ards must be met before an airport can qualify for an ATCT: PART 171—NON-FEDERAL (1) The airport, whether publicly or NAVIGATION FACILITIES privately owned, must be open to and available for use by the public as de- Subpart A—VOR Facilities fined in the Airport and Airway Im- provement Act of 1982; Sec.
(2) The airport must be recognized by 171.1 Scope.
and contained within the National 171.3 Requests for IFR procedure.
Plan of Integrated Airport Systems; 171.5 Minimum requirements for approval.
(3) The airport owners/authorities 171.7 Performance requirements.
must have entered into appropriate as- 171.9 Installation requirements.
surances and covenants to guarantee 171.11 Maintenance and operations require- that the airport will continue in oper- ments.
ation for a long enough period to per- 171.13 Reports.
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