OBSTACLE- An existing
object, object of natural growth, or terrain at a fixed geographical location or
which may be expected at a fixed location within a prescribed area with
reference to which vertical clearance is or must be provided during flight
PROCEDURE (ODP)- A preplanned instrument flight rule (IFR) departure procedure
printed for pilot use in textual or graphic form to provide obstruction
clearance via the least onerous route from the terminal area to the appropriate
en route structure. ODPs are recommended for obstruction clearance and may be
flown without ATC clearance unless an alternate departure procedure (SID or
radar vector) has been specifically assigned by ATC.
(See IFR TAKEOFF MINIMUMS AND
(See STANDARD INSTRUMENT
(Refer to AIM.)
OBSTACLE FREE ZONE- The
OFZ is a three dimensional volume of airspace which protects for the transition
of aircraft to and from the runway. The OFZ clearing standard precludes taxiing
and parked airplanes and object penetrations, except for frangible NAVAID
locations that are fixed by function. Additionally, vehicles, equipment, and
personnel may be authorized by air traffic control to enter the area using the
provisions of FAAO JO 7110.65, Para 3-1-5, VEHICLES/EQUIPMENT/PERSONNEL
ON RUNWAYS. The runway OFZ and when applicable, the inner-approach OFZ, and the
inner-transitional OFZ, comprise the OFZ.
a. Runway OFZ. The
runway OFZ is a defined volume of airspace centered above the runway. The runway
OFZ is the airspace above a surface whose elevation at any point is the same as
the elevation of the nearest point on the runway centerline. The runway OFZ
extends 200 feet beyond each end of the runway. The width is as follows:
1. For runways
serving large airplanes, the greater of:
(a) 400 feet, or
(b) 180 feet, plus
the wingspan of the most demanding airplane, plus 20 feet per 1,000 feet of
2. For runways
serving only small airplanes:
(a) 300 feet for
precision instrument runways.
(b) 250 feet for
other runways serving small airplanes with approach speeds of 50 knots, or more.
(c) 120 feet for
other runways serving small airplanes with approach speeds of less than 50
OFZ. The inner-approach OFZ is a defined volume of airspace centered on the
approach area. The inner-approach OFZ applies only to runways with an approach
lighting system. The inner-approach OFZ begins 200 feet from the runway
threshold at the same elevation as the runway threshold and extends 200 feet
beyond the last light unit in the approach lighting system. The width of the
inner-approach OFZ is the same as the runway OFZ and rises at a slope of 50
(horizontal) to 1 (vertical) from the beginning.
OFZ. The inner transitional surface OFZ is a defined volume of airspace along
the sides of the runway and inner-approach OFZ and applies only to precision
instrument runways. The inner-transitional surface OFZ slopes 3 (horizontal) to
1 (vertical) out from the edges of the runway OFZ and inner-approach OFZ to a
height of 150 feet above the established airport elevation.
(Refer to AC 150/5300-13,
(Refer to FAAO JO 7110.65,
Para 3-1-5, VEHICLES/EQUIPMENT/PERSONNEL ON RUNWAYS.)
object/obstacle exceeding the obstruction standards specified by 14 CFR Part 77,
OBSTRUCTION LIGHT- A light
or one of a group of lights, usually red or white, frequently mounted on a
surface structure or natural terrain to warn pilots of the presence of an
OCEANIC AIRSPACE- Airspace
over the oceans of the world, considered international airspace, where oceanic
separation and procedures per the International Civil Aviation Organization are
applied. Responsibility for the provisions of air traffic control service in
this airspace is delegated to various countries, based generally upon geographic
proximity and the availability of the required resources.
DISPLAY AND PLANNING SYSTEM- An automated digital display system which provides
flight data processing, conflict probe, and situation display for oceanic air
OCEANIC NAVIGATIONAL ERROR
REPORT- A report filed when an aircraft exiting oceanic airspace has been
observed by radar to be off course. ONER reporting parameters and procedures are
contained in FAAO 7110.82, Monitoring of Navigational Performance In Oceanic
OCEANIC PUBLISHED ROUTE- A
route established in international airspace and charted or described in flight
information publications, such as Route Charts, DOD Enroute Charts, Chart
Supplements, NOTAMs, and Track Messages.
OCEANIC TRANSITION ROUTE-
An ATS route established for the purpose of transitioning aircraft to/from an
organized track system.
(See OCEANIC DISPLAY AND
(See OBSTACLE DEPARTURE
OFF COURSE- A term used to
describe a situation where an aircraft has reported a position fix or is
observed on radar at a point not on the ATC-approved route of flight.
OFF-ROUTE VECTOR- A vector
by ATC which takes an aircraft off a previously assigned route. Altitudes
assigned by ATC during such vectors provide required obstacle clearance.
OFFSET PARALLEL RUNWAYS-
Staggered runways having centerlines which are parallel.
AREA- That portion of airspace between the U.S. 12 NM limit and the oceanic CTA/FIR
boundary within which air traffic control is exercised. These areas are
established to provide air traffic control services. Offshore/Control Airspace
Areas may be classified as either Class A airspace or Class E airspace.
(See OUTER FIX TIME.)
(See OUTER MARKER.)
a. Used to indicate
that an aircraft is established on the route centerline.
b. Used by ATC to
advise a pilot making a radar approach that his/her aircraft is lined up on the
final approach course.
(See ON-COURSE INDICATION.)
ON-COURSE INDICATION- An
indication on an instrument, which provides the pilot a visual means of
determining that the aircraft is located on the centerline of a given
navigational track, or an indication on a radar scope that an aircraft is on a
ONE-MINUTE WEATHER- The
most recent one minute updated weather broadcast received by a pilot from an
uncontrolled airport ASOS/AWSS/AWOS.
(See OCEANIC NAVIGATIONAL
(See DUE REGARD.)
OPERATIONS SPECIFICATIONS [ICAO]- The
authorizations, conditions and limitations associated
with the air operator certificate and subject to the
conditions in the operations manual.
AIRCRAFT- Aircraft are operating in opposite directions when:
a. They are
following the same track in reciprocal directions; or
b. Their tracks are
parallel and the aircraft are flying in reciprocal directions; or
c. Their tracks
intersect at an angle of more than 135°.
OPTION APPROACH- An
approach requested and conducted by a pilot which will result in either a
touch-and-go, missed approach, low approach, stop-and-go, or full stop landing.
(See CLEARED FOR THE OPTION.)
(Refer to AIM.)
ORGANIZED TRACK SYSTEM- A
series of ATS routes which are fixed and charted; i.e., CEP, NOPAC, or flexible
and described by NOTAM; i.e., NAT TRACK MESSAGE.
OROCA- An off-route
altitude which 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 United States. This altitude may not provide signal coverage
from ground-based navigational aids, air traffic control radar, or
(See OCEANIC TRANSITION
(See ORGANIZED TRACK SYSTEM.)
conversation is ended and no response is expected.
OUTER AREA (associated
with Class C airspace)- Nonregulatory airspace surrounding designated Class C
airspace airports wherein ATC provides radar vectoring and sequencing on a
full-time basis for all IFR and participating VFR aircraft. The service provided
in the outer area is called Class C service which includes: IFR/IFR-standard IFR
separation; IFR/VFR-traffic advisories and conflict resolution; and VFR/VFR-traffic
advisories and, as appropriate, safety alerts. The normal radius will be 20
nautical miles with some variations based on site-specific requirements. The
outer area extends outward from the primary Class C airspace airport and extends
from the lower limits of radar/radio coverage up to the ceiling of the approach
control's delegated airspace excluding the Class C charted area and other
airspace as appropriate.
(See CONFLICT RESOLUTION.)
(See CONTROLLED AIRSPACE.)
OUTER COMPASS LOCATOR-
(See COMPASS LOCATOR.)
OUTER FIX- A general term
used within ATC to describe fixes in the terminal area, other than the final
approach fix. Aircraft are normally cleared to these fixes by an Air Route
Traffic Control Center or an Approach Control Facility. Aircraft are normally
cleared from these fixes to the final approach fix or final approach course.
OUTER FIX- An adapted fix
along the converted route of flight, prior to the meter fix, for which crossing
times are calculated and displayed in the metering position list.
OUTER FIX ARC- A
semicircle, usually about a 50-70 mile radius from a meter fix, usually in high
altitude, which is used by CTAS/HOST to calculate outer fix times and determine
appropriate sector meter list assignments for aircraft on an established arrival
route that will traverse the arc.
OUTER FIX TIME- A
calculated time to depart the outer fix in order to cross the vertex at the ACLT.
The time reflects descent speed adjustments and any applicable delay time that
must be absorbed prior to crossing the meter fix.
OUTER MARKER- A marker
beacon at or near the glideslope intercept altitude of an ILS approach. It is
keyed to transmit two dashes per second on a 400 Hz tone, which is received
aurally and visually by compatible airborne equipment. The OM is normally
located four to seven miles from the runway threshold on the extended centerline
of the runway.
(See INSTRUMENT LANDING
(See MARKER BEACON.)
(Refer to AIM.)
transmission is ended; I expect a response.
OVERHEAD MANEUVER- A
series of predetermined maneuvers prescribed for aircraft (often in formation)
for entry into the visual flight rules (VFR) traffic pattern and to proceed to a
landing. An overhead maneuver is not an instrument flight rules (IFR) approach
procedure. An aircraft executing an overhead maneuver is considered VFR and the
IFR flight plan is cancelled when the aircraft reaches the "initial point" on
the initial approach portion of the maneuver. The pattern usually specifies the
a. The radio
contact required of the pilot.
b. The speed to be
c. An initial
approach 3 to 5 miles in length.
d. An elliptical
pattern consisting of two 180 degree turns.
e. A break point at
which the first 180 degree turn is started.
f. The direction of
g. Altitude (at
least 500 feet above the conventional pattern).
h. A "Roll-out" on
final approach not less than 1/4 mile from the landing threshold and not less
than 300 feet above the ground.
OVERLYING CENTER- The ARTCC facility that is responsible for arrival/departure
operations at a specific terminal.