Aeronautical Terms beginning with O
OAT
Outside Air Temperature
OBS
Omni-bearing Selector
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 operation.
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.
Obstruction
Any object/obstacle exceeding the obstruction standards specified by 14 CFR Part 77, Subpart C.
Obstruction lights
Lights that can be found both on and off an airport to identify obstructions.
Offset Parallel Runways
Staggered runways having centerlines which are parallel.
On Course
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.
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 given track.
One-Minute Weather
The most recent one minute updated weather broadcast received by a pilot from an uncontrolled airport ASOS/AWSS/AWOS.
Operate
With respect to aircraft, use, cause to use or authorize to use aircraft, for the purpose (except as provided in §91.13 of this chapter) of air navigation including the piloting of aircraft, with or without the right of legal control (as owner, lessee, or otherwise).
Operational control
With respect to a flight, the exercise of authority over initiating, conducting or terminating a flight.
Opposite Direction 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.
OTS
Out of service
Out
The 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.
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.
Over
My transmission is ended; I expect a response.
Over-the-top
Above the layer of clouds or other obscuring phenomena forming the ceiling.
Overcontrolling
Using more movement in the control column than is necessary to achieve the desired pitch-and-bank condition.
Overpower
To use more power than required for the purpose of achieving a faster rate of airspeed change.
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