Airport Operations

The law defines airports by categories of airport activities, Towered Airport including commercial service, primary, cargo service, A towered airport has an operating control tower. Air traffic reliever, and general aviation airports, as shown below: control (ATC) is responsible for providing the safe, orderly, • Commercial Service Airports—publicly owned and expeditious flow of air traffic at airports where the airports that have at least 2,500 passenger boardings type of operations and/or volume of traffic requires such a each calendar year and receive scheduled passenger service. Pilots operating from a towered airport are required service. Passenger boardings refer to revenue passenger to maintain two-way radio communication with ATC and to boardings on an aircraft in service in air commerce acknowledge and comply with their instructions. Pilots must whether or not in scheduled service. The definition advise ATC if they cannot comply with the instructions issued also includes passengers who continue on an aircraft and request amended instructions. A pilot may deviate from in international flight that stops at an airport in any of an air traffic instruction in an emergency, but must advise the 50 States for a non-traffic purpose, such as refueling ATC of the deviation as soon as possible. or aircraft maintenance rather than passenger activity. Passenger boardings at airports that receive scheduled Nontowered Airport passenger service are also referred to as Enplanements. A nontowered airport does not have an operating control tower. Two-way radio communications are not required, • Cargo Service Airports—airports that, in addition to any although it is a good operating practice for pilots to transmit other air transportation services that may be available, their intentions on the specified frequency for the benefit are served by aircraft providing air transportation of of other traffic in the area. The key to communicating at an only cargo with a total annual landed weight of more airport without an operating control tower is selection of the than 100 million pounds. “Landed weight” means the correct common frequency. The acronym CTAF, which stands weight of aircraft transporting only cargo in intrastate, for Common Traffic Advisory Frequency, is synonymous interstate, and foreign air transportation. An airport with this program. A CTAF is a frequency designated for may be both a commercial service and a cargo service the purpose of carrying out airport advisory practices while airport. operating to or from an airport without an operating control • Reliever Airports—airports designated by the FAA tower. The CTAF may be a Universal Integrated Community to relieve congestion at Commercial Service Airports (UNICOM), MULTICOM, Flight Service Station (FSS), or and to provide improved general aviation access to the tower frequency and is identified in appropriate aeronautical overall community. These may be publicly or privately- publications. UNICOM is a nongovernment air/ground radio owned. communication station that may provide airport information • General Aviation Airports — the remaining airports at public use airports where there is no tower or FSS. On pilot are commonly described as General Aviation Airports. request, UNICOM stations may provide pilots with weather This airport type is the largest single group of airports information, wind direction, the recommended runway, or in the U.S. system. The category also includes privately other necessary information. If the UNICOM frequency owned, public use airports that enplane 2500 or more is designated as the CTAF, it is identified in appropriate passengers annually and receive scheduled airline aeronautical publications. Figure 14-1 lists recommended service. communication procedures. More information regarding radio communications is provided later in this chapter. Types of Airports Nontowered airport traffic patterns are always entered at There are two types of airports—towered and nontowered. pattern altitude. How you enter the pattern depends upon the These types can be further subdivided to: direction of arrival. The preferred method for entering from • Civil Airports—airports that are open to the general the downwind side of the pattern is to approach the pattern public. on a course 45 degrees to the downwind leg and join the • Military/Federal Government airports—airports pattern at midfield. operated by the military, National Aeronautics and Space Administration (NASA), or other agencies of There are several ways to enter the pattern if you’re coming the Federal Government. from the upwind leg side of the airport. One method of entry from the opposite side of the pattern is to announce your • Private Airports—airports designated for private or intentions and cross over midfield at least 500 feet above restricted use only, not open to the general public. 14-2