Minimum Reception Altitude (MRA). An MRA is determined
by FAA flight inspection traversing an entire route of flight
to establish the minimum altitude the navigation signal can
be received for the route and for off-course NAVAID facilities
that determine a fix. When the MRA at the fix is higher than
the MEA, an MRA is established for the fix, and is the lowest
altitude at which an intersection can be determined.
Minimum Safe Altitude (MSA) . MSAs are published for
emergency use on IAP charts. For conventional navigation
systems, the MSA is normally based on the primary
omnidirectional facility on which the IAP is predicated.
For RNAV approaches, the MSA is based on the runway
waypoint (RWY WP) for straight-in approaches, or the
airport waypoint (APT WP) for circling approaches. For
GPS approaches, the MSA center is the Missed Approach
Waypoint (MAWP).
Minimum Vectoring Altitude (MVA). Minimum vectoring
altitude charts are developed for areas where there are
numerous minimum vectoring altitudes due to variable
terrain features or man-made obstacles. MVAs are
established for use by ATC when radar ATC is exercised.
Missed Approach Holding Waypoint . An approach
waypoint sequenced during the holding portion of the
missed approach procedure that is a fly-over waypoint.
Missed Approach Waypoint (MAWP). An approach waypoint
sequenced during the missed approach procedure that is
a fly-over waypoint.
National Airspace System (NAS) . Consists of a complex
collection of facilities, systems, equipment, procedures, and
airports operated by thousands of people to provide a safe
and efficient flying environment.
Navigational Gap . A navigational course guidance gap,
referred to as an MEA gap, describes a distance along an
airway or route segment where a gap in navigational signal
coverage exists. The navigational gap may not exceed a
specific distance that varies directly with altitude.
Next Generation Air Transportation System (NextGen) .
Ongoing, wide-ranging transformation of the National
Airspace System (NAS). NextGen represents an evolution
from a ground-based system of air traffic control to a satellite-
based system of air traffic management.
Non-Directional Radio Beacon (NDB) . An L/MF or UHF
radio beacon transmitting nondirectional signals whereby
the pilot of an aircraft equipped with direction finding
equipment can determine bearing to or from the radio
beacon and “home”on or track to or from the station. When
the radio beacon is installed in conjunction with the ILS
marker, it is normally called a compass locator.
Non-RNAV DP . A DP whose ground track is based on
ground-based NAVAIDS and/or dead reckoning navigation.
Obstacle Clearance Surface (OCS) . An inclined or level
surface associated with a defined area for obstruction
evaluation.
Obstacle Departure Procedure (ODP) . A procedure that
provides obstacle clearance. ODPs do not include ATC
related climb requirements. In fact, the primary emphasis
of ODP design is to use the least erroneous route of flight to
the en route structure while attempting to accommodate
typical departure routes.
Obstacle Identification Surface (OIS) . The design of a
departure procedure is based on FAA Order 8260.3, a living
document that is updated frequently. Departure design
criteria assumes an initial climb of 200 Ft/NM after crossing
the departure end of the runway (DER) at a height of at
least 35 feet above the ground. Assuming a 200 Ft/NM
climb, the departure is structured to provide at least 48 Ft/
NM of clearance above objects that do not penetrate the
obstacle slope. The slope, known as the OIS, is based on a
40 to 1 ratio, which is the equivalent of a 152 Ft/NM slope.
Off-Airway Routes. The FAA prescribes altitudes governing
the operation of aircraft under IFR for fairway routes in a
similar manner to those on federal airways, jet routes, area
navigation low or high altitude routes, and other direct
routes for which an MEA is designated.
Off-Route Obstruction Clearance Altitude (OROCA). An off-
route altitude that provides obstruction clearance with a
1,000-foot buffer in nonmountainous terrain areas and a
2,000-foot buffer in designated mountainous areas within
the U.S. This altitude may not provide signal coverage from
groundbased navigational aids, air traffic control radar, or
communications coverage.
Operations Specifications (OpSpecs) . A published
document providing the conditions under which an air carrier
and operator for compensation or hire must operate in order
to retain approval from the FAA.
Pilot Briefing Information. The current format for charted
IAPs issued by Aeronautical Information Services. The
information is presented in a logical order facilitating
pilot briefing of the procedures. Charts include formatted
information required for quick pilot or flight crew reference
located at the top of the chart.
Point-in-Space (PinS) Approach . An approach normally
developed to heliports that do not meet the IFR heliport
design standards but meet the standards for a VFR
heliport. A helicopter PinS approach can be developed
using conventional NAVAIDs or RNAV systems. These
procedures have either a VFR or visual segment between the
MAP and the landing area. The procedure specifies a course
and distance from the MAP to the heliport(s) and includes a
note to proceed VFR or visually from the MAP to the heliport,
or conduct the missed approach.
Positive Course Guidance (PCG). The continuous display
of accurate course and flight path data that enables a pilot
to precisely fly along a specific track or course using RNAV,
a ground-based NAVAID or a radar vector. For RNAV or a
ground-based NAVAID, the guidance is displayed in the
aircraft; for a radar vector, the guidance data is displayed
in the radar facility
Precision Runway Monitor (PRM) . Provides air traffic
controllers with high precision secondary surveillance
data for aircraft on final approach to parallel runways that
have extended centerlines separated by less than 4,300
feet. High resolution color monitoring displays (FMA) are
required to present surveillance track data to controllers
along with detailed maps depicting approaches and a no
transgression zone.
Preferential Departure Route (PDR) . A specific departure
route from an airport or terminal area to an en route point
where there is no further need for flow control. It may be
included in an instrument Departure Procedure (DP) or a
Preferred IFR Route.
Preferred IFR Routes . A system of preferred IFR routes
guides you in planning your route of flight to minimize
route changes during the operational phase of flight, and
to aid in the efficient orderly management of air traffic
using federal airways.
Principal Operations Inspector (POI). Scheduled air carriers
and operators for compensation or hire are assigned a POI
who works directly with the company and coordinates FAA
operating approval.
Record. See Database Record.
Reduced Vertical Separation Minimums (RVSM) . RVSM
airspace is where air traffic control separates aircraft by
a minimum of 1,000 feet vertically between flight level
(FL) 290 and FL 410 inclusive. RVSM airspace is special
qualification airspace; the operator and the aircraft used
by the operator must be approved by the Administrator.
Air traffic control notifies operators of RVSM by providing
route planing information.
Reference Landing Speed (VREF). The speed of the aircraft,
in a specified landing configuration, at the point where it
descends through the 50-foot height in the determination
of the landing distance.
Remote Communications Outlet (RCO) . An unmanned
communications facility remotely controlled by air traffic
personnel. RCOs serve FSSs and may be UHF or VHF. RCOs
extend the communication range of the air traffic facility.
RCOs were established to provide ground-to-ground
communications between air traffic control specialists
and pilots located at a satellite airport for delivering en
route clearances, issuing departure authorizations, and
acknowledging IFR cancellations or departure/landing
times.
Reporting Point . A geographical location in relation
to which the position of an aircraft is reported. (See
Compulsory Reporting Points).
Required Navigation Performance (RNP). RNP is a statement
of the navigation performance necessary for operation
within a defined airspace. On-board monitoring and
alerting is required.
RNAV DP. A Departure Procedure developed for RNAV-
equipped aircraft whose ground track is based on satellite
or DME/DME navigation systems.
Roll-Out RVR . The RVR readout values obtained from
sensors located nearest the rollout end of the runway.
Runway Heading. The magnetic direction that corresponds
with the runway centerline extended, not the painted
runway numbers on the runway. Pilots cleared to “fly or
maintain runway heading” are expected to fly or maintain
the published heading that corresponds with the extended
centerline of the departure runway (until otherwise
instructed by ATC), and are not to apply drift correction
(e.g., RWY 4, actual magnetic heading of the runway
centerline 044.22°, fly 044°).
Runway Hotspots. Locations on a particular airport that
historically have hazardous intersections. Hot spots alert
pilots to the fact that there may be a lack of visibility at
certain points or the tower may be unable to see that
particular intersection. Whatever the reason, pilots need
to be aware that these hazardous intersections exist and
they should be increasingly vigilant when approaching
and taxiing through these intersections. Pilots are typically
notified of these areas by a Letter to Airmen or by accessing
the FAA Office of Runway Safety.
Runway Incursion. An occurrence at an airport involving
an aircraft, vehicle, person, or object on the ground that
creates a collision hazard or results in a loss of separation
with an aircraft that is taking off, intending to take off,
landing, or intending to land.
Runway Safety Program (RSP) . Designed to create and
execute a plan of action that reduces the number of runway
incursions at the nation’s airports.
Runway Visual Range (RVR). An estimate of the maximum
distance at which the runway, or the specified lights or
markers delineating it, can be seen from a position above
a specific point on the runway centerline. RVR is normally
determined by visibility sensors or transmissometers
located alongside and higher than the centerline of the
runway. RVR is reported in hundreds of feet.
Runway Visibility Value (RVV). The visibility determined
for a particular runway by a transmissometer. A meter
provides a continuous indication of the visibility (reported
in miles or fractions of miles) for the runway. RVV is used
in lieu of prevailing visibility in determining minimums for
a particular runway.
Significant Point. [ICAO Annex 11] A specified geographical
location used in defining an ATS route or the flightpath
of an aircraft and for other navigation and ATS purposes.
Special Instrument Approach Procedure . A procedure
approved by the FAA for individual operators, but not
published in 14 CFR Part 97 for public use.
Special Use Airspace Management System (SAMS) . A
joint FAA and military program designed to improve civilian
access to special use airspace by providing information on
whether the airspace is active or scheduled to be active. The
information is available to authorized users via an Internet
website.
Standard Instrument Departure (SID) . An ATC requested
and developed departure route designed to increase capacity
of terminal airspace, effectively control the flow of traffic
with minimal communication, and reduce environmental
impact through noise abatement procedures.
Standard Service Volume . Most air navigation radio aids
that provide positive course guidance have a designated
standard service volume (SSV). The SSV defines the
reception limits of unrestricted NAVAIDS that are usable for
random/unpublished route navigation. Standard service
volume limitations do not apply to published IFR routes or
procedures. See the AIM (Chapter 1) for the SSV for specific
NAVAID types.
Standard Terminal Arrival (STAR) . Provides a common
method for departing the en route structure and navigating
to your destination. A STAR is a preplanned instrument
flight rule ATC arrival procedure published for pilot use
in graphic and textual form to simplify clearance delivery
procedures. STARs provide you with a transition from
the en route structure to an outer fix or an instrument
approach fix or arrival waypoint in the terminal area. STARs
usually terminate with an instrument or visual approach
procedure, but may also terminate with a heading or course
to fly for radar vectors.
Standard Terminal Arrival (STAR) Charts. Designed to
expedite air traffic control arrival procedures and to
facilitate transition between en route and instrument
approach operations. Each STAR procedure is presented
as a separate chart and may serve a single airport or more
than one airport in a given geographical location
Standardized Taxi Routes . Coded taxi routes that follow
typical taxiway traffic patterns to move aircraft between
gates and runways. ATC issues clearances using these
coded routes to reduce radio communication and eliminate
taxi instruction misinterpretation.
STAR Transition. A published segment used to connect
one or more en route airways, jet routes, or RNAV routes
to the basic STAR procedure. It is one of several routes that
bring traffic from different directions into one STAR. STARs
are published for airports with procedures authorized by
the FAA, and these STARs are included at the front of each
Terminal Procedures Publication regional booklet.
Start End of Runway (SER) . The beginning of the takeoff
runway available.
Station Declination. The angular difference between true
north and the zero radial of a VOR at the time the VOR was
last site-checked.
Surface Incident. An event during which authorized or
unauthorized/unapproved movement occurs in the
movement area or an occurrence in the movement area
associated with the operation of an aircraft that affects or
could affect the safety of flight.
Surface Movement Guidance Control System (SMGCS) .
Facilitates the safe movement of aircraft and vehicles
at airports where scheduled air carriers are conducting
authorized operations. The SMGCS low visibility taxi plan
includes the improvement of taxiway and runway signs,
markings, and lighting, as well as the creation of SMGCS
low visibility taxi route charts.
Synthetic Vision Guidance System (SVGS). SVGS is a
combination of flight guidance display technology and
high precision position assurance monitors. The SVGS flight
instrument display provides a continuous, geo-spatially
correct depiction of the external scene topography,
including obstacles, augmented by the display of the
runway of intended landing. The SVGS display may be
implemented on a head down Primary Flight Display, and/
or a Head-Up Display (HUD). SVGS includes additional
symbology elements, integrity and performance monitors
and annunciations that support and enable low visibility
operations. Additional flight instrument symbology and
monitors to assure accurate rendering of the external
scene are included.
Synthetic Vision System (SVS) . An electronic means to
display a synthetic vision image of the external scene
topography to the flight crew.
System Wide Information Management (SWIM) .
An advanced technology program designed to facilitate
greater sharing of Air Traffic Management (ATM) system
information, such as airport operational status, weather
information, flight data, status of special use airspace,
and National Airspace System (NAS) restrictions. SWIM
supports current and future NAS programs by providing
flexible and secure information management architecture for
sharing NAS information.
Takeoff Distance Available (TODA). ICAO defines TODA as
the length of the takeoff runway available plus the length
of the clearway, if provided.
Takeoff Runway Available (TORA). ICAO defines TORA as
the length of runway declared available and suitable for
the ground run of an aeroplane takeoff.
Tangent Point (TP). The point on the VOR/DME RNAV route
centerline from which a line perpendicular to the route
centerline would pass through the reference facility.
Terminal Arrival Area (TAA). TAAs are the method by which
aircraft are transitioned from the RNAV en route structure
to the terminal area with minimal ATC interaction. The TAA
consists of a designated volume of airspace designed to
allow aircraft to enter a protected area, offering guaranteed
obstacle clearance where the initial approach course is
intercepted based on the location of the aircraft relative
to the airport.
Threshold. The beginning of the part of the runway usable
for landing.
Top Of Climb (TOC). An identifiable waypoint representing
the point at which cruise altitude is first reached. TOC is
calculated based on your current aircraft altitude, climb
speed, and cruise altitude. There can only be one TOC
waypoint at a time.
Top Of Descent (TOD) . Generally utilized in flight
management systems, top of descent is an identifiable
waypoint representing the point at which descent is first
initiated from cruise altitude. TOD is generally calculated
using the destination elevation (if available) and the
descent speed schedule.
Touchdown and Lift-Off Area (TLOF) . The TLOF is a load
bearing, usually paved, area at a heliport where the
helicopter is permitted to land. The TLOF can be located
at ground or rooftop level, or on an elevated structure. The
TLOF is normally centered in the FATO.
Touchdown RVR . The RVR visibility readout values
obtained from sensors serving the runway touchdown zone.
Touchdown Zone Elevation (TDZE). The highest elevation
in the first 3,000 feet of the landing surface.
Tower En Route Control (TEC). The control of IFR en route
traffic within delegated airspace between two or more
adjacent approach control facilities. This service is designed
to expedite air traffic and reduces air traffic control and
pilot communication requirements.
TRACAB. A new type of air traffic facility that consists of
a radar approach control facility located in the tower cab of
the primary airport, as opposed to a separate room.
Traffic Information Service-Broadcast (TIS-B) . An air
traffic surveillance system that combines all available traffic
information on a single display.
Traffic Management Advisor (TMA). A software suite that
helps air traffic controllers to sequence arriving air traffic.
Transition Altitude (QNH). The altitude in the vicinity of an
airport at or below which the vertical position of an aircraft
is controlled by reference to altitudes (MSL).
Transition Height (QFE). Transition height is the height in
the vicinity of an airport at or below which the vertical
position of an aircraft is expressed in height above the
airport reference datum.
Transition Layer. Transition layer is the airspace between
the transition altitude and the transition level. Aircraft
descending through the transition layer will set altimeters
to local station pressure, while departing aircraft climbing
through the transition layer will be using standard altimeter
setting (QNE) of 29.92 inches of Mercury, 1013.2 millibars,
or 1013.2 hectopascals.
Transition Level (QNE). The lowest flight level available for
use above the transition altitude.
Turn Anticipation . The capability of RNAV systems to
determine the point along a course, prior to a turn WP ,
where a turn should be initiated to provide a smooth path
to intercept the succeeding course and to enunciate the
information to the pilot.
Turn WP (Turning Point). A WP that identifies a change from
one course to another.
Universal Communications (UNICOM) . An air-ground
communication facility operated by a private agency to
provide advisory service at uncontrolled aerodromes and
airports.
User-Defined Waypoint. User-defined waypoints typically
are created by pilots for use in their own random RNAV
direct navigation. They are newly established, unpublished
airspace fixes that are designated geographic locations/
positions that help provide positive course guidance for
navigation and a means of checking progress on a flight.
They may or may not be actually plotted by the pilot on
en route charts, but would normally be communicated to
ATC in terms of bearing and distance or latitude/longitude.
An example of user-defined waypoints typically includes
those derived from database-driven area navigation (RNAV)
systems whereby latitude/longitude coordinate-based
waypoints are generated by various means including
keyboard input, and even electronic map mode functions
used to establish waypoints with a cursor on the display.
Another example is an offset phantom waypoint, which
is a point in space formed by a bearing and distance from
NAVAIDs, such as VORs, VORTACs, and TACANs, using a
variety of navigation systems.
User Request Evaluation Tool (URET). The URET helps
provide enhanced, automated flight data management.
URET is an automated tool provided at each radar position
in selected en route facilities. It uses flight and radar data
to determine present and future trajectories for all active
and proposed aircraft flights. A graphic plan display
depicts aircraft, traffic, and notification of predicted
conflicts. Graphic routes for current plans and trial plans
are displayed upon controller request. URET can generate
a predicted conflict of two aircraft, or between aircraft
and airspace.
Vertical Navigation (VNAV) . Traditionally, the only way
to get glidepath information during an approach was to
use a ground-based NAVAID, but modern area navigation
systems allow flight crews to display an internally
generated descent path that allows a constant rate descent
to minimums during approaches that would otherwise
include multiple level-offs.
Vertical Navigation Planning. Included within certain STARs
is information provided to help you reduce the amount of
low altitude flying time for high performance aircraft, like
jets and turboprops. An expected altitude is given for a key
fix along the route. By knowing an intermediate altitude in
advance when flying a high performance aircraft, you can
plan the power or thrust settings and aircraft configurations
that result in the most efficient descent, in terms of time,
fuel requirements, and engine wear.
Visual Approach. A visual approach is an ATC authorization
for an aircraft on an IFR flight plan to proceed visually to
the airport of intended landing; it is not an IAP . Also, there
is no missed approach segment. When it is operationally
beneficial, ATC may authorize pilots to conduct a visual
approach to the airport in lieu of the published IAP . A visual
approach can be initiated by a pilot or the controller.
Visual Climb Over the Airport (VCOA) . An option to allow
an aircraft to climb over the airport with visual reference
to obstacles to attain a suitable altitude from which to
proceed with an IFR departure.
Waypoints . Area navigation waypoints are specified
geographical locations, or fixes, used to define an area
navigation route or the flightpath of an aircraft employing
area navigation. Waypoints may be any of the following
types: predefined, published, floating, user-defined, fly-by,
or fly-over.
Waypoint (WP). A predetermined geographical position
used for route/instrument approach definition, progress
reports, published VFR routes, visual reporting points or
points for transitioning and/or circumnavigating controlled
and/or special use airspace, that is defined relative
to a VORTAC station or in terms of latitude/longitude
coordinates.
Wide Area Augmentation System (WAAS) . A method of
navigation based on GPS. Ground correction stations transmit
position corrections that enhance system accuracy and add
vertical navigation (VNAV) features.