A

ADVISORY CIRCULAR (AC) - Federal Aviation Administration Advisory Circular. This is a FAA document, which provides guidance on aviation issues.

AIR CARRIERS - This includes the commercial system of air transportation and consists of certified route air carriers, air taxis (including commuters) supplemental air carriers, commercial operators of large aircraft, and air travel clubs.  Air Carriers are certified under FAA regulations to carry passengers under FAR Part 121, 127, 135, etc. 

AIRFIELD CAPACITY - Airfield capacity is the maximum number of aircraft operations that can be accommodated by an airport’s runways and taxiways over a specified time period (e.g. hourly capacity).

Airport slots – The number of landings or takeoffs allowed for a specified time period. Slots are sometimes used at commercial airports when the hourly demand significantly exceeds hourly capacity. In the United States, the only airports with slot restrictions are Kennedy and LaGuardia in New York, National in Washington, DC, and O'Hare in Chicago.

AIRPORT TRAFFIC CONTROL TOWER (ATCT) - A facility providing airport traffic control service to an airport and its associated airspace area.

AIR TAXI - A FAR Part 135 certificated air carrier carrying passengers and cargo for hire and operating under exemption authority from the Civil Aeronautics Board; aircraft of 30 seats or less or maximum payloads of 7,500 lbs.

ANNUAL SERVICE VOLUME (ASV) - ASV is a reasonable estimate of an airport's annual capacity.  It accounts for differences in runway use, aircraft mix, weather conditions, etc., that would be encountered over a year's time.

APPROACH END OF RUNWAY - The approach end of runway is the near end of the runway as viewed from the cockpit of a landing airplane.

 ATC - Air traffic control. This is the system under which all aircraft must operate.

Available ton miles (ATMs) - Tons multiplied by miles flown. It is an international measure of the capacity available for a carrier. It is also used to measure capacity available for freight carriers.

Available seat miles (ASM) - The number of seats available multiplied by the number of miles flown. This measures an airline's capacity capability. For example, a transport configured to fly 100 seats that goes 100 miles would give the carrier 10,000 ASMs for that particular flight.

  Available seat kilometers (ASK) -  The number of seats flown multiplied by the number of kilometers they are flown.

Available ton kilometers (ATK) -  The number of tons capable of being carried, multiplied by the number of kilometers flown.

Average fare - Passenger revenue divided by the number of passengers.

B

BASED AIRCRAFT - An aircraft permanently stationed at an airport by agreement between the airport owner (management or FBO) and the aircraft owner.  

Block hours - The time between when an aircraft departs the gate and its arrival at its destination gate.

Bilateral aviation agreement - An agreement between two countries similar to a treaty, but concerning only aviation rights.

Breakeven load factor (BELF) - The load factor necessary for the carrier to financially break even. It is a function of the percentage of seats filled at a particular yield vs. the airline’s operating costs.

C

CAPACITY - The maximum number of aircraft operations that can be accommodated by an airport (or airport component) over a specified time period (e.g. hourly capacity). When the demand exceeds capacity, the level of delay rapidly increases.

CAPITAL COSTS - Non-recurring or infrequently recurring costs of long-term assets, such as land, guideways, stations, buildings, and vehicles.

Code-sharing - A growing practice in which airlines share the same two-letter designator code on certain flights, as they are presented in the various computer reservations systems used by airlines and travel agents. Sharing of the codes permits a travel agent or airline to sell a ticket that will include routings of both carriers where codes are shared.

COMMERCIAL SERVICE AIRPORT - A public airport, which enplanes 2,500 or more passengers annually and receives scheduled commercial passenger service. See “AIR CARRIER” for more information.

COMMUTER AIRLINES - Scheduled commuter air carrier operating with passengers, cargo, or mail for revenue in accordance with FAR Part 135 or Part 121.

Computer reservations systems - The electronic system that allows travel agents or airlines to reserve seats on commercial flights.

CONGESTION - The volume of traffic at which a road, airport, or other transportation facility is no longer operating at an acceptable level of service.

Cost per available seat mile (CASM) - The unit operating cost of a carrier, also known as unit cost. The cost expressed in cents to operate each seat mile offered. Determined by dividing operating costs by ASMs.

D

DELAY – The difference between constrained and unconstrained operating time for an aircraft.

DEMAND MANAGEMENT - a method of controlling airport access by promoting more effective or economically efficient use of existing facilities.  The two most prevalent methods are differential pricing and auctioning of landing rights.

DESIGN AIRCRAFT - The Design Aircraft is an aircraft whose dimensions and/or other requirements make it the most demanding aircraft for an airport’s facilities (i.e. runways and taxiways).  The Design Aircraft is used as the basis for airport planning and design; because if the airport’s facilities are designed to accommodate the Design Aircraft, they can accommodate less demanding aircraft as well.   An aircraft can be utilized as the Design Aircraft for an airport if it has or is expected to conduct 500 or more annual operations (250 landings) at that airport.

DISPOSABLE PERSONAL INCOME - personal income less personal tax and non-tax payments. It is the income available to persons for spending or saving.

E

ENHANCEMENT PROJECTS - Various scenic, historic and environmental activities eligible for project funding under the Surface Transportation Program (STP) element of Federal Transportation funding resources.

F

FEDERAL AVIATION REGULATION (FAR) - Regulations developed by the FAA in order to maintain safety, define standards, and institute uniform practices throughout the industry.

FEDERAL HIGHWAY ADMINISTRATION (FHWA) - Division of the U.S. Department of Transportation which administers the funds for highway planning and capital programs.

FEDERAL TRANSIT ADMINISTRATION (FTA) - Division of the U.S. Department of Transportation that administers the funds for transit planning and capital/operating programs.

Financing (or Dry) lease - Lease in which the service provided by the lessor to the lessee is limited to financial equipment. All other responsibilities related to the possession of equipment, such as maintenance, insurance, and taxes, are borne by the lessee. A financial lease is usually non-cancellable, and is fully paid out (amortized) over its term.

FIXED BASE OPERATION OR FIXED BASE OPERATOR (FBO) - A sales and/or service facility located at an airport, or the person who operates such a facility.

FRACTIONAL OWNERSHIP – An aircraft ownership concept whereby multiple companies can partially own an aircraft.  A common aircraft management company is used to maintain the aircraft and administer the leasing of the aircraft among the owners.  The aircraft owners participating in the program agree not only to share their aircraft with others having an ownership interest in that aircraft, but also to lease their aircraft to other owners in the program.

 FREE FLOW - Roadway conditions in which vehicles are almost completely unimpeded in their ability to maneuver within the traffic stream.

FUNCTIONAL CLASSIFICATION - The grouping of streets and highways into classes, or systems, according to the character of service they are intended to provide. Basic to this process is the recognition that roads do not function independently, but rather as a system-wide network of roads.

G

GENERAL AVIATION (GA) - All civil aircraft and aviation activity except that of the certified air carriers and military operations.  GA includes corporate flying and private flying (recreation or personal).

GROSS DOMESTIC PRODUCT (GDP) - the featured measure of U.S. output, is the market value of the goods and services produced by labor and property located in the United States.  Because the labor and property are located in the United States, the suppliers (that is, the workers and, for property, the owners) may be either U.S. residents or residents of the rest of the world.

GROSS NATIONAL PRODUCT (GNP) - the market value of the goods and services produced by labor and property supplied by U.S. residents. Because the labor and property are supplied by U.S. residents, they may be located either in the United States or abroad. The difference between GDP and GNP is net receipts of income from the rest of the world.

H

HIGH OCCUPANCY VEHICLES (HOV) - Vehicles carrying a specified minimum number of persons, usually three or more. Freeways may have lanes designated for HOV use by car-poolers, vanpools and buses.

I

INSTRUMENT FLIGHT RULES (IFR) - Aircraft operation rules as pre-scribed by Federal Aviation Regulations for flying by instruments.

INTEGRATED NOISE MODEL (INM) – A computer program typically used for FAR Part 150 noise compatibility planning and for FAA Order 1050 environmental assessment and environmental impact statements.

INTELLIGENT TRANSPORTATION SYSTEMS (ITS) - Electronic, computer and communications technology applied to surface transportation to increase safety, reduce congestion, enhance mobility, minimize environmental impact, increase energy efficiency and promote economic productivity for a healthier economy.

INTERMODAL - A transportation system connecting or including different modes of transportation.

INTERMODAL SURFACE TRANSPORTATION EFFICIENCY ACT OF 1991 (ISTEA) - The most recent legislation passed by the U.S. Congress that authorizes Federal funding through 1997 for highway and transit purposes. The Act reinforces MPO responsibilities and provides more flexibility in transportation planning and programming decision making.

ITINERANT OPERATIONS - All aircraft operations other than local operations.

L

  LAND USE - The manner in which land or the structures on land are used (i.e., commercial, residential, industrial, etc.).

LARGE AIRCRAFT - A large aircraft is an aircraft of more than 12,500 pounds (5,700 kg) for its maximum certificated takeoff weight.

Leases - Contracts granting use of equipment (aircraft) for a specified time in exchange for payment, usually in the form of rent. The owner of the leased property is called the lessor, the user the lessee.

Lease purchase agreement - Agreement providing that portions of lease payment may be applied toward the purchase of the property under lease.

Length of hop - The average distance of a flight or stage length.

LEVEL OF SERVICE (LOS) - The quality of flow in the moving stream of people or vehicles. Typically, ranges from LOS A (free flow traffic) to LOS F (stop-and-go unacceptable conditions).

Load factor (LF) - The percentage of seats filled. Determined by dividing RPMs by ASMs as a percentage (%).

LOCAL OPERATION - Operations performed by an aircraft that:

(a) Operates within the local traffic pattern or within sight of the airport;

(b) Are known to be departing for or arriving from an Airport within a 20-mile radius of the Airport in question; or

(c) Execute practice maneuvers such as touch and goes or simulated instrument approaches at the airport.

The majority of local operations are conducted by based aircraft.

LONG RANGE TRANSPORTATION PLAN - A 15 to 20 year forecast plan which must consider a wide range of social, environmental, energy and economic factors. The plan addresses overall regional goals and how transportation can best meet those goals within financial limits.

M

  METROPOLITAN PLANNING AREA - The region in which the MPO carries out its transportation planning responsibilities and is designated as such by the MPO and the Governor in accordance with ISTEA regulations.

METROPOLITAN PLANNING ORGANIZATION (MPO) - The agency designated by the Governor to administer the federally required transportation decision-making process in urbanized areas with over 50,000 population.

MODE - A particular form of travel, for example, walking or traveling by automobile, transit or bicycle.

 

MODE SPLIT - The process by which the number of trips that will be made by two or more modes of transportation is surveyed or estimated.

MOVEMENT AREA - The runways, taxiways, and other areas of an airport which are used for taxiing, takeoff, and landing of aircraft, excluding loading ramps and parking areas.

Multilateral aviation greement - an agreement for air service among more than two nations (see "Freedoms of the Air").

N

NATIONAL HIGHWAY SYSTEM (NHS) - A 155,000 mile system of roads, authorized through ISTEA. Comprised of Interstate highways and roads designated as most important to interstate travel, national defense, intermodal connections, and international crossings. Congressional approval of the NHS system was formalized by the National Highway System Act of 1995.

NAUTICAL MILE (NM) - The unit measure of distance in both nautical and aeronautical context. A nautical mile equals 1.15 statute miles (6,080 feet). The measure of speed in regards to nautical miles is known as KNOTS (nautical miles per hour).

Network airline - An airline that operates a hub-and-spoke system.

NATIONAL AIRSPACE SYSTEM (NAS) - The common system of air navigation and air traffic control encompassing communications facilities, air navigation facilities, airways, controlled airspace special use airspace, and flight procedures authorized by FAR's for domestic and international aviation.

NON ATTAINMENT AREA - Any geographic region that has been designated as non-attainment due to transportation related pollutant(s) that violates the national ambient air quality standard. The Clean Air Act requires that these areas perform air quality analyses and determinations to ensure conformity.

NOTICE TO AIRMEN (NOTAM)- A notice identified either as a NOTAM or an Airmen Advisory containing information concerning the establishment, condition, or change in any component of, or hazard in, the National Airspace System, the timely knowledge of which is essential to personnel concerned with flight operations.

O

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).

  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.

P

  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 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).

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.

R

 

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.

Revenue per available seat mile (RASM) - The revenue generated for each available seat mile operated, expressed in cents. Revenue divided by ASMs.

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 passenger kilometers (RPK) - The number of passengers multiplied by the number of kilometers they fly.

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.

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.

RIGHT-OF-WAY (ROW) - Land corridors needed for the construction of highways, transit facilities, railroads, etc.

RUNWAY (R/W) - A runway is a defined rectangular area on an airport prepared for the landing or takeoff of airplanes.

S

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.

SEPARATION - Spacing of aircraft to achieve their safe and orderly movement in flight and while landing and taking off.

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.

SMALL AIRCRAFT - A small aircraft is an aircraft of 12,500 pounds (5,700 kg) or less maximum certificated takeoff weight.

Stage length (see length of hop) - The average distance flown per flight.

STATUTE MILE - A mile measuring 5,280 feet (in contrast to a nautical mile of 6,080 feet).

SURFACE TRANSPORTATION PROGRAM (STP) - A capital funding program legislated by ISTEA for a variety of highway, transit, pedestrian and bicycle projects.

T

T/W - Taxiway.

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.

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.

THRESHOLD - The threshold is the beginning of that portion of the runway available and suitable for the landing of airplanes.

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.

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.

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.

Turboprops – Turbine-engined aircraft that operates with propellers and typically serves narrow markets, and feeds major carrier hubs.

U

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.

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.

V

 

VEHICLE MILES OF TRAVEL (VMT) - The amount of vehicle travel on a designated set of roadways multiplied by the total mileage of those roadways.

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.

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.

VFR TRAFFIC - Aircraft traffic operated solely in accordance with Visual Flight Rules.

VOLUME - The number of vehicles that actually pass through a given mile of road; can also be applied to transit or bicycle/pedestrian paths.

W

 

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.

  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.

Y

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.