Terms and Definitions A - G
Terms and Definitions H - N
Terms and Definitions O - Z
O - Z
OEI means one engine inoperative.
OM means ILS outer marker.
Operate, with respect to aircraft, means 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).
Operating lease - Type of lease, normally involving equipment, whereby the contract is written for considerably less than the life of the equipment, and the lessor handles all maintenance and servicing; also called service lease. Most operating leases are cancelable, meaning the lessee can return the equipment if it becomes obsolete, or is no longer needed.
OPERATION - A take-off, landing or touch-an-go of an aircraft. FAA ATCT operations include all radio contacts with an aircraft, regardless of whether or not they are taking off or landing. Operations used for planning purposes include only takeoffs, landings and touch and goes (which count as 2 operations).
Operational control, with respect to a flight, means the exercise of authority over initiating, conducting or terminating a flight.
Operator Any person who causes or authorizes the operation of an aircraft, such as the owner, lessee, or bailee of an aircraft.
Origination/Destination (O&D) - A measure of the point of origination of a passenger to the final destination. It is the true trip of the passenger, although the passenger may change flights and planes at least once during the journey. It allows carriers to determine where their true business lies.
Overseas air commerce means the carriage by aircraft of persons or property for compensation or hire, or the carriage of mail by aircraft, or the operation or navigation of aircraft in the conduct or furtherance of a business or vocation, in commerce between a place in any State of the United States, or the District of Columbia, and any place in a territory or possession of the United States; or between a place in a territory or possession of the United States, and a place in any other territory or possession of the United States.
Overseas air transportation (1) Between a place in a State or the District of Columbia and a place in a possession of the United States; or
Overseas air transportation (2) Between a place in a possession of the United States and a place in another possession of the United States; whether that commerce moves wholly by aircraft or partly by aircraft and partly by other forms of transportation.
Overseas air transportation means the carriage by aircraft of persons or property as a common carrier for compensation or hire, or the carriage of mail by aircraft, in commerce:
Over-the-top means above the layer of clouds or other obscuring phenomena forming the ceiling.
PAR means precision approach radar.
Parachute means a device used or intended to be used to retard the fall of a body or object through the air.
Passenger haul (PAX length of haul) - The average distance flown per passenger. It includes the total distance traveled from connecting flights. Measured in terms of miles.
PEAK - The period during which the maximum amount of travel occurs. It may be specified as the morning (a.m.) or evening (p.m.) peak.
Person means an individual, firm, partnership, corporation, company, association, joint-stock association, or governmental entity. It includes a trustee, receiver, assignee, or similar representative of any of them.
PERSON TRIP - A trip made by a person from a single origin to a single destination.
PERSONAL CONSUMPTION EXPENDITURES (PCE) - goods and services purchased by U.S. residents. PCE consists mainly of purchases of new goods and of services by individuals from private business.
PERSONAL INCOME - the income received by persons from all sources—that is, from participation in production, from both government and business transfer payments, and from government interest (which is treated like a transfer payment).
Pilot in command (1) Has final authority and responsibility for the operation and safety of the flight;
Pilot in command (2) Has been designated as pilot in command before or during the flight; and
Pilot in command A578(3) Holds the appropriate category, class, and type rating, if appropriate, for the conduct of the flight.
Pilot in command means the person who:
Pilotage means navigation by visual reference to landmarks.
Pitch setting means the propeller blade setting as determined by the blade angle measured in a manner, and at a radius, specified by the instruction manual for the propeller.
Positive control means control of all air traffic, within designated airspace, by air traffic control.
Powered-lift means a heavier-than-air aircraft capable of vertical takeoff, vertical landing, and low speed flight that depends principally on engine-driven lift devices or engine thrust for lift during these flight regimes and on nonrotating airfoil(s) for lift during horizontal flight.
Precautionary Landing A landing necessitated by apparent impending failure of engines, systems, or components which makes continued flight inadvisable.
Precision approach procedure means a standard instrument approach procedure in which an electronic glide slope is provided, such as ILS and PAR.
Pressure Altitude. Altitude in the earth's atmosphere above mean standard sea level pressure datum plane, measured by a pressure (barometric) altimeter set to standard pressure (29.92 inches of mercury).
Preventive maintenance means simple or minor preservation operations and the replacement of small standard parts not involving complex assembly operations.
Prohibited area. A prohibited area is airspace designated under part 73 within which no person may operate an aircraft without the permission of the using agency.
Propeller means a device for propelling an aircraft that has blades on an engine-driven shaft and that, when rotated, produces by its action on the air, a thrust approximately perpendicular to its plane of rotation. It includes control components normally supplied by its manufacturer, but does not include main and auxiliary rotors or rotating airfoils of engines.
Pseudo-range. The distance from the user to a satellite plus an unknown user clock offset distance. With four satellite signals it is possible to compute position and offset distance.
Public aircraft means an aircraft used only for the United States Government, or owned and operated (except for commercial purposes), or exclusively leased for at least 90 continuous days, by a government (except the United States Government), including a State, the District of Columbia, or a territory or possession of the United States, or political subdivision of that government; but does not include a government-owned aircraft transporting property for commercial purposes, or transporting passengers other than transporting (for other than commercial purposes) crewmembers or other persons aboard the aircraft whose presence is required to perform, or is associated with the performance of, a governmental function such as firefighting, search and rescue, law enforcement, aeronautical research, or biological or geological resource management; or transporting (for other than commercial purposes) persons aboard the aircraft if the aircraft is operated by the Armed Forces or an intelligence agency of the United States. An aircraft described in the preceding sentence shall, notwithstanding any limitation relating to use of the aircraft for commercial purposes, be considered to be a public aircraft for the purposes of this Chapter without regard to whether the aircraft is operated by a unit of government on behalf of another unit of government, pursuant to a cost reimbursement agreement between such units of government, if the unit of government on whose behalf the operation is conducted certifies to the Administrator of the Federal Aviation Administration that the operation was necessary to respond to a significant and imminent threat to life or property (including natural resources) and that no service by a private operator was reasonably available to meet the threat.
Pure freighter aircraft An aircraft that is designed to carry freight. This type of aircraft can transport larger and oddly shaped items that cannot fit into the cargo area of a passenger aircraft.
RAIL means runway alignment indicator light system.
Rated 2 1/2-minute OEI power, with respect to rotorcraft turbine engines, means the approved brake horsepower developed under static conditions at specified altitudes and temperatures within the operating limitations established for the engine under Part 33 of this chapter, and limited in use to a period of not more than 2 1/2 minutes after the failure of one engine of a multiengine rotorcraft.
Rated 2-minute OEI power, with respect to rotorcraft turbine engines, means the approved brake horsepower developed under static conditions at specified altitudes and temperatures within the operating limitations established for the engine under part 33 of this chapter, for continued one-flight operation after the failure of one engine in multiengine rotorcraft, limited to three periods of use no longer than 2 minutes each in any one flight, and followed by mandatory inspection and prescribed maintenance action.
Rated 30-minute OEI power, with respect to rotorcraft turbine engines, means the approved brake horsepower developed under static conditions at specified altitudes and temperatures within the operating limitations established for the engine under Part 33 of this chapter, and limited in use to a period of not more than 30 minutes after the failure of one engine of a multiengine rotorcraft.
Rated 30-second OEI power, with respect to rotorcraft turbine engines, means the approved brake horsepower developed under static conditions at specified altitudes and temperatures within the operating limitations established for the engine under part 33 of this chapter, for continued one-flight operation after the failure of one engine in multiengine rotorcraft, limited to three periods of use no longer than 30 seconds each in any one flight, and followed by mandatory inspection and prescribed maintenance action.
Rated continuous OEI power, with respect to rotorcraft turbine engines, means the approved brake horsepower developed under static conditions at specified altitudes and temperatures within the operating limitations established for the engine under Part 33 of this chapter, and limited in use to the time required to complete the flight after the failure of one engine of a multiengine rotorcraft.
Rated maximum continuous augmented thrust, with respect to turbojet engine type certification, means the approved jet thrust that is developed statically or in flight, in standard atmosphere at a specified altitude, with fluid injection or with the burning of fuel in a separate combustion chamber, within the engine operating limitations established under Part 33 of this chapter, and approved for unrestricted periods of use.
Rated maximum continuous power, with respect to reciprocating, turbopropeller, and turboshaft engines, means the approved brake horsepower that is developed statically or in flight, in standard atmosphere at a specified altitude, within the engine operating limitations established under Part 33, and approved for unrestricted periods of use.
Rated maximum continuous thrust, with respect to turbojet engine type certification, means the approved jet thrust that is developed statically or in flight, in standard atmosphere at a specified altitude, without fluid injection and without the burning of fuel in a separate combustion chamber, within the engine operating limitations established under Part 33 of this chapter, and approved for unrestricted periods of use.
Rated takeoff augmented thrust, with respect to turbojet engine type certification, means the approved jet thrust that is developed statically under standard sea level conditions, with fluid injection or with the burning of fuel in a separate combustion chamber, within the engine operating limitations established under Part 33 of this chapter, and limited in use to periods of not over 5 minutes for takeoff operation.
Rated takeoff power, with respect to reciprocating, turbopropeller, and turboshaft engine type certification, means the approved brake horsepower that is developed statically under standard sea level conditions, within the engine operating limitations established under Part 33, and limited in use to periods of not over 5 minutes for takeoff operation.
Rated takeoff thrust, with respect to turbojet engine type certification, means the approved jet thrust that is developed statically under standard sea level conditions, without fluid injection and without the burning of fuel in a separate combustion chamber, within the engine operating limitations established under Part 33 of this chapter, and limited in use to periods of not over 5 minutes for takeoff operation.
Rating means a statement that, as a part of a certificate, sets forth special conditions, privileges, or limitations.
RBN means radio beacon.
RCLM means runway centerline marking.
RCLS means runway centerline light system.
Receiver Autonomous Integrity Monitoring (RAIM). A technique whereby a civil GPS receiver/processor determines the integrity of the GPS navigation signals using only GPS signals or GPS signals augmented with altitude. This determination is achieved by a consistency check among redundant pseudo-range measurements. At least one satellite in addition to those required for navigation must be in view for the receiver to perform the RAIM function.
Reference landing speed means the speed of the airplane, in a specified landing configuration, at the point where it descends through the 50 foot height in the determination of the landing distance.
Regional airline - Commuter airline that typically operates in a specific region. Most regional airline traffic feeds network carriers.
Regional jets (RJs) – A new generation of commercial jets with fewer than 100 seats. On many routes, RJs are replacing turboprop aircraft, which have been unpopular with many passengers. Some large carriers have scope clause agreements with their pilots' unions, that limit the number of R]s that can be used by the commuter feed carriers that operate them in conjunction with the large airline.
REIL means runway end identification lights.
RELIEVER AIRPORT - An airport designated as having the primary function of relieving congestion at a commercial airport and providing more general aviation access to the overall community. Reliever Airports are allowed to receive AIP (federal) funds for improvement.
Reporting point means a geographical location in relation to which the position of an aircraft is reported.
Restricted area. A restricted area is airspace designated under Part 73 within which the flight of aircraft, while not wholly prohibited, is subject to restriction.
Revenue passenger kilometers (RPK) - The number of passengers multiplied by the number of kilometers they fly.
Revenue passenger miles (RPM) - The principal measure of the airline passenger business. It represents the number of paying passengers flown by the distance flown.
Revenue per available seat mile (RASM) - The revenue generated for each available seat mile operated, expressed in cents. Revenue divided by ASMs.
Revenue ton kilometers (RTK) - The number of tons carried multiplied by the number of kilometers flown.
Revenue ton miles (RTMs) - The revenue generated for each ton mile operated.
RIGHT-OF-WAY (ROW) - Land corridors needed for the construction of highways, transit facilities, railroads, etc.
RNAV way point (W/P) means a predetermined geographical position used for route or instrument approach definition or progress reporting purposes that is defined relative to a VORTAC station position.
Rocket means an aircraft propelled by ejected expanding gases generated in the engine from self-contained propellants and not dependent on the intake of outside substances. It includes any part which becomes separated during the operation.
Rotorcraft means a heavier-than-air aircraft that depends principally for its support in flight on the lift generated by one or more rotors.
Rotorcraft-load combination (1) Class A rotorcraft-load combination means one in which the external load cannot move freely, cannot be jettisoned, and does not extend below the landing gear.
Rotorcraft-load combination (2) Class B rotorcraft-load combination means one in which the external load is jettisonable and is lifted free of land or water during the rotorcraft operation.
Rotorcraft-load combination (3) Class C rotorcraft-load combination means one in which the external load is jettisonable and remains in contact with land or water during the rotorcraft operation.
Rotorcraft-load combination (4) Class D rotorcraft-load combination means one in which the external-load is other than a Class A, B, or C and has been specifically approved by the Administrator for that operation.
Rotorcraft-load combination means the combination of a rotorcraft and an external-load, including the external-load attaching means. Rotorcraft-load combinations are designated as Class A, Class B, Class C, and Class D, as follows:
Route segment means a part of a route. Each end of that part is identified by:
RR means low or medium frequency radio range station.
RUNWAY (R/W) - A runway is a defined rectangular area on an airport prepared for the landing or takeoff of airplanes.
RVR means runway visual range as measured in the touchdown zone area.
Sale and leaseback - Form of lease arrangement in which a company sells an asset to another party - usually an insurance or finance company, a leasing company, a limited partnership, or an institutional investor - in exchange for cash, then contracts to lease the asset for a specified term. Such arrangements frequently have tax benefits for the lessee. A company generally opts for the sale and leaseback arrangement as an alternative to straight financing, when the rate it would need to pay a lender is higher than the cost of rental, or when it wishes to show less debt on its balance sheet.
SALS means short approach light system.
Scope clause - Provisions in US major airlines' pilot contracts that impose limits on the operation of jet airplanes used by regional "partner" airlines. Limits on seat count (generally 70 seats or less), weight, cruise speed, or ratio of regional jets to standard jets, are the most common provisions.
Sea level engine means a reciprocating aircraft engine having a rated takeoff power that is producible only at sea level.
Second in command means a pilot who is designated to be second in command of an aircraft during flight time.
SEPARATION - Spacing of aircraft to achieve their safe and orderly movement in flight and while landing and taking off.
Serious Injury Any injury which: (1) requires hospitalization for more than 48 hours, commencing within 7 days from the date the injury was received; (2) results in a fracture of any bone (except simple fractures of fingers, toes, or nose); (3) causes severe hemorrhages, nerve, muscle, or tendon damage; (4) involves any internal organ; or (5) involves second or third degree burns, or any burns affecting more than 5 percent of the body surface.
Show, unless the context otherwise requires, means to show to the satisfaction of the Administrator.
SMALL AIRCRAFT - A small aircraft is an aircraft of 12,500 pounds (5,700 kg) or less maximum certificated takeoff weight.
Small aircraft means aircraft of 12,500 pounds or less, maximum certificated takeoff weight.
Special VFR conditions mean meteorological conditions that are less than those required for basic VFR flight in controlled airspace and in which some aircraft are permitted flight under visual flight rules.
Special VFR operations means aircraft operating in accordance with clearances within controlled airspace in meteorological conditions less than the basic VFR weather minima. Such operations must be requested by the pilot and approved by ATC.
SSALS means simplified short approach light system.
SSALSR means simplified short approach light system with runway alignment indicator lights.
Stage length (see length of hop) - The average distance flown per flight.
Stand Alone GPS Navigation System. Stand alone GPS equipment is equipment that is not combined with other navigation sensors or navigation systems such as DME, Loran C, Omega, Inertial, etc. Stand alone GPS equipment can, however, include other augmentation features such as altimetry smoothing, clock coasting, etc.
Standard atmosphere means the atmosphere defined in U.S. Standard Atmosphere, 1962 (Geopotential altitude tables).
Statistically Accountable Accidents Those in which USFS exercised operational control of the aircraft.
STATUTE MILE - A mile measuring 5,280 feet (in contrast to a nautical mile of 6,080 feet).
Stopway means an area beyond the takeoff runway, no less wide than the runway and centered upon the extended centerline of the runway, able to support the airplane during an aborted takeoff, without causing structural damage to the airplane, and designated by the airport authorities for use in decelerating the airplane during an aborted takeoff.
Substantial Damage Damage or failure which adversely affects the structural strength, performance, or flight characteristics of the aircraft, and which would normally require major repair or replacement of the affected component. Engine failure or damage limited to an engine if only one engine fails or is damaged, bent fairings or cowling, dented skin, small punctured holes in the skin or fabric, ground damage to rotor or propeller blades, and damage to landing gear, wheels, tires, flaps, engine accessories, brakes, or wing tips are not considered "substantial damage" for the purpose of 49 CFR Part 830.
Supplemental Air Navigation System. An FAA approved navigation system that can be used for navigation provided an alternate navigation system, which meets all of the regulatory requirements for the route of flight, is also installed on the aircraft.
SURFACE TRANSPORTATION PROGRAM (STP) - A capital funding program legislated by ISTEA for a variety of highway, transit, pedestrian and bicycle projects.
System Availability. The percentage of time (specified as 98 percent) that at least 21 of the 24 GPS satellites must be operational and providing a usable navigation signal.
T/W - Taxiway.
TACAN means ultra-high frequency tactical air navigational aid.
Takeoff power: (1) With respect to reciprocating engines, means the brake horsepower that is developed under standard sea level conditions, and under the maximum conditions of crankshaft rotational speed and engine manifold pressure approved for the normal takeoff, and limited in continuous use to the period of time shown in the approved engine specification; and (2) With respect to turbine engines, means the brake horsepower that is developed under static conditions at a specified altitude and atmospheric temperature, and under the maximum conditions of rotor shaft rotational speed and gas temperature approved for the normal takeoff, and limited in continuous use to the period of time shown in the approved engine specification.
Takeoff safety speed means a referenced airspeed obtained after lift-off at which the required one-engine-inoperative climb performance can be achieved.
Takeoff thrust, with respect to turbine engines, means the jet thrust that is developed under static conditions at a specific altitude and atmospheric temperature under the maximum conditions of rotorshaft rotational speed and gas temperature approved for the normal takeoff, and limited in continuous use to the period of time shown in the approved engine specification.
Tandem wing configuration means a configuration having two wings of similar span, mounted in tandem.
TAS means true airspeed.
TAXI - To operate an airplane under its own power on the ground, except the movement incident to actual takeoff and landing.
TAXIWAY - A taxiway is a defined path, from one part of an airport to another, selected or prepared for the taxiing of aircraft.
TCAS I means a TCAS that utilizes interrogations of, and replies from, airborne radar beacon transponders and provides traffic advisories to the pilot.
TCAS II means a TCAS that utilizes interrogations of, and replies from airborne radar beacon transponders and provides traffic advisories and resolution advisories in the vertical plane.
TCAS III means a TCAS that utilizes interrogation of, and replies from, airborne radar beacon transponders and provides traffic advisories and resolution advisories in the vertical and horizontal planes to the pilot.
TCAS means a traffic alert and collision avoidance system.
TDZL means touchdown zone lights.
TERMINAL AREA CAPACITY - The ability of the terminal area to accept the passengers, cargo, and aircraft that the airfield accommodates. Individual elements within terminal areas must be evaluated to determine overall terminal capacity. Terminal elements included in the analysis are: airline gate positions, airline apron areas, cargo apron areas, general aviation apron areas, airline passenger terminals, general aviation terminals, cargo buildings, automobile parking and aircraft maintenance facilities.
Terminal Area Operations. Those flight phases conducted on charted Standard Instrument Departures (SIDs), on Standard Terminal Arrivals (STARs), or other flight operations between the last en route fix/waypoint and an initial approach fix/waypoint.
The majority of local operations are conducted by based aircraft.
THRESHOLD - The threshold is the beginning of that portion of the runway available and suitable for the landing of airplanes.
Time in service, with respect to maintenance time records, means the time from the moment an aircraft leaves the surface of the earth until it touches it at the next point of landing.
TOUCH AND GO - A training operation in which a landing approach is made, the aircraft touches-down on the runway, but does not fully reduce speed to turn off the runway. Instead, after the landing, full engine power is applied while still rolling and a takeoff is made, thereby practicing both maneuvers as part of one motion. It counts as two separate aircraft operations.
TRACK - The flight path of an aircraft over the surface of the earth.
Track Angle Error. Track angle error is the difference between the desired track and actual track (magnetic or true).
TRAFFIC ANALYSIS ZONE (TAZ) - The smallest geographically designated area for analysis of transportation activity.
TRAFFIC PATTERN - The traffic flow that is prescribed for aircraft landing at or taking off from an airport. The usual traffic pattern consists of five segments, or “legs”. These components are the upwind leg, crosswind leg, downwind leg, base leg, and the final approach. Traffic patterns are followed by aircraft in order to exit the airport area after takeoff in an orderly fashion, and to enter an Airport area and ultimately land, also in an orderly fashion.
Traffic pattern means the traffic flow that is prescribed for aircraft landing at, taxiing on, or taking off from, an airport.
TRANSFER PAYMENTS - transfer payments to persons and transfer payments to the rest of the world (net). The latter consists of U.S. Government military and nonmilitary grants in cash and non military grants in kind to foreign governments and of U.S. Government transfers, mainly retirement benefits, to former residents of the United States.
TRANSPORT AIRPORT - A transport airport is an airport designed, constructed, and maintained to specifically serve airplanes in Aircraft Approach Category C and D. Please refer to the definition for Aircraft Approach Category. Airports, which accommodate Category C and D aircraft on a semi regular basis are not necessarily Transport Airports.
TRANSPORT CATEGORY AIRCRAFT - Aircraft with a maximum Gross takeoff weight of 12,500 pounds or more.
TRANSPORTATION DEMAND MANAGEMENT - Programs and policies to reduce peak demand for transportation and to maximize efficient use of the transportation system. Such strategies may include HOV lanes, ride sharing and vanpooling, and congestion pricing.
TRANSPORTATION ENHANCEMENT PROGRAM (TEP) - Federal program which provides capital funds for "non-traditional" transportation projects such as bicycle and pedestrian facilities, historic preservation of transportation facilities, and transportation-related landscaping and scenic beautification.
TRANSPORTATION IMPROVEMENT PROGRAM (TIP) - A capital investment program prepared by the MPO cooperatively with the State and transit operator that prioritizes transportation projects to be implemented with Federal funds over a five year period.
TRANSPORTATION NETWORK - A schematic representation of the roadway or transit system via a series of links and nodes in a computer database.
TRAVEL FORECASTING - The technical process of estimating the number of future users by mode of a system and their particular travel times and routes.
TRIP ASSIGNMENT - The process of allocating highway and transit trips among the different facilities included in a network.
TRIP DISTRIBUTION - The process of estimating the travel between traffic analysis zones.
TRIP GENERATION - The process of estimating trips that will be produced and/or attracted to a geographic unit based on the population and employment characteristics of that unit.
Trip length - The average length of journey in terms of miles for a passenger.
True airspeed means the airspeed of an aircraft relative to undisturbed air. True airspeed is equal to equivalent airspeed multiplied by (?0/?) 1/2.
Turboprops – Turbine-engined aircraft that operates with propellers and typically serves narrow markets, and feeds major carrier hubs.
TVOR means very high frequency terminal omnirange station.
Type (2) As used with respect to the certification of aircraft, means those aircraft which are similar in design. Examples include: DC-7 and DC-7C; 1049G and 1049H; and F-27 and F-27F.
Type (3) As used with respect to the certification of aircraft engines means those engines which are similar in design. For example, JT8D and JT8D-7 are engines of the same type, and JT9D-3A and JT9D-7 are engines of the same type.
Type:(1) As used with respect to the certification, ratings, privileges, and limitations of airmen, means a specific make and basic model of aircraft, including modifications thereto that do not change its handling or flight characteristics. Examples include: DC-7, 1049, and F-27; and
Unit cost - The cost per available seat mile (ASM). Obtained by counting total operating costs and dividing it by the ASMs. Expressed in cents.
Unit revenue - The average revenue generated per available seat mile (passenger revenue/ASMs), expressed in cents.
United States air carrier means a citizen of the United States who undertakes directly by lease, or other arrangement, to engage in air transportation.
United States, in a geographical sense, means (1) the States, the District of Columbia, Puerto Rico, and the possessions, including the territorial waters, and (2) the airspace of those areas.
URBANIZED AREA - An area with a population of 50,000 or more designated by the U.S. Census Bureau.
UTILITY AIRPORT - A utility airport is an airport designed, constructed, and maintained to serve smaller (single and twin-engine) airplanes.
V1 means the maximum speed in the takeoff at which the pilot must take the first action (e.g., apply brakes, reduce thrust, deploy speed brakes) to stop the airplane within the accelerate-stop distance. V1 also means the minimum speed in the takeoff, following a failure of the critical engine at VEF, at which the pilot can continue the takeoff and achieve the required height above the takeoff surface within the takeoff distance.
V2 means takeoff safety speed.
V2min means minimum takeoff safety speed.
VA means design maneuvering speed.
VA means design maneuvering speed.
VB means design speed for maximum gust intensity.
VB means design speed for maximum gust intensity.
VC means design cruising speed.
VC means design cruising speed.
VD means design diving speed.
VD means design diving speed.
VDF/MDF means demonstrated flight diving speed.
VDF/MDF means demonstrated flight diving speed.
VEF means the speed at which the critical engine is assumed to fail during takeoff.
VEF means the speed at which the critical engine is assumed to fail during takeoff.
VEHICLE MILES OF TRAVEL (VMT) - The amount of vehicle travel on a designated set of roadways multiplied by the total mileage of those roadways.
VF means design flap speed.
VF means design flap speed.
VFC/MFC means maximum speed for stability characteristics.
VFC/MFC means maximum speed for stability characteristics.
VFE means maximum flap extended speed.
VFE means maximum flap extended speed.
VFR CONDITIONS - Basic weather conditions prescribed for flight under Visual Flight Rules; usually implies a ceiling of at least 1000 feet and a forward visibility of three miles or more.
VFR means visual flight rules.
VFR over-the-top, with respect to the operation of aircraft, means the operation of an aircraft over-the-top under VFR when it is not being operated on an IFR flight plan.
VFR TRAFFIC - Aircraft traffic operated solely in accordance with Visual Flight Rules.
VFTO means final takeoff speed.
VH means maximum speed in level flight with maximum continuous power.
VH means maximum speed in level flight with maximum continuous power.
VHF means very high frequency.
VISIBILITY, PREVAILING - The horizontal distance at which targets of known distance are visible over at least half of the horizon. It is normally determined by an observer on or close to the ground viewing buildings or other similar objects during the day and ordinary city lights at night.
VISUAL FLIGHT RULES (VFR) - "See and be seen" flight rules. Each pilot is responsible for the safe spacing and proper operation of his aircraft. Under VFR, a pilot is not required to file a flight plan or be in constant radar and communication contact with air traffic control. Visual flight rules are determined by weather and require a ceiling of at least 1,000 feet and visibility of at least 3 miles.
VLE means maximum landing gear extended speed.
VLE means maximum landing gear extended speed.
VLO means maximum landing gear operating speed.
VLO means maximum landing gear operating speed.
VLOF means lift-off speed.
VLOF means lift-off speed.
VMC means minimum control speed with the critical engine inoperative.
VMC means minimum control speed with the critical engine inoperative.
VMO/MMO means maximum operating limit speed.
VMO/MMO means maximum operating limit speed.
VMU means minimum unstick speed.
VMU means minimum unstick speed.
VNE means never-exceed speed.
VNE means never-exceed speed.
VNO means maximum structural cruising speed.
VNO means maximum structural cruising speed.
VOLUME - The number of vehicles that actually pass through a given mile of road; can also be applied to transit or bicycle/pedestrian paths.
VOR means very high frequency omnirange station.
VORTAC means collocated VOR and TACAN.
VR means rotation speed.
VR means rotation speed.
VREF means reference landing speed.
VS means the stalling speed or the minimum steady flight speed at which the airplane is controllable.
VS means the stalling speed or the minimum steady flight speed at which the airplane is controllable.
VS0 means the stalling speed or the minimum steady flight speed in the landing configuration.
VS1 means the stalling speed or the minimum steady flight speed obtained in a specific configuration.
VSR means reference stall speed.
VSR1 means reference stall speed in a specific configuration.
VSRO means reference stall speed in the landing configuration.
VSW means speed at which onset of natural or artificial stall warning occurs.
VTOSS means takeoff safety speed for Category A rotorcraft.
VX means speed for best angle of climb.
VY means speed for best rate of climb.
WAKE TURBULENCE - The air turbulence caused by a moving aircraft, originating at the tips of the wings. The turbulence is caused by vortices generated by an aircraft’s wingtips as it travels through the air. This turbulence is greatest when the aircraft is taking off and landing.
Warning area. A warning area is airspace of defined dimensions, extending from 3 nautical miles outward from the coast of the United States, that contains activity that may be hazardous to nonparticipating aircraft. The purpose of such warning areas is to warn nonparticipating pilots of the potential danger. A warning area may be located over domestic or international waters or both.
Wet (or ACMI) lease - A lease in which not only the aircraft is provided, but also other services are included, as well as hull insurance, crews, and maintenance guarantees.
WIND COVERAGE - Wind coverage is the percent of time for which aeronautical operations are considered safe due to acceptable crosswind components.
Winglet or tip fin means an out-of-plane surface extending from a lifting surface. The surface may or may not have control surfaces.
Yield (revenue per revenue passenger mile) - A function of passenger revenue generated, divided by the revenue passenger miles generated. It is expressed in cents per mile, and measures the average level of fares at which the airline is selling its product.
YIELD MANAGEMENT - Also known as revenue management, the process airline use to set prices for a flight. The goal is to find the mix of seat prices that produces the most revenue.
Yield management systems - Computer-managed systems that airlines have installed and are constantly perfecting, to better enable them to manage price and seat inventories, enabling the carriers to sell the maximum number of seats at the most productive yield mix.
