Finding Air Traffic Frequencies
From The RadioReference Wiki
Revision as of 08:35, 26 January 2013 by QDP2012 (removed Category:Aircraft Monitoring; added sub-category:Air Traffic Control)
- 1 Overview
- 2 General Commercial Frequencies
- 3 Aircraft Emergency/Distress
- 4 Air to Air
- 5 Domestic VHF/Operational Control ("Company Frequencies")
- 6 Identifying Aircraft vs. Frequency
- 7 CodeShare (Airline Partners)
- 8 Google Earth 3D tracking
- 9 Identifying Frequency vs. Airport
- 10 Notes
Airborne planes can easily be heard from well over 100 miles, so you don't have to live near an airport. If you do live near an airport, you can find out all the traffic control, weather, and Traffic Advisory frequencies by entering the airport at AirNav.
At most small airports that don't have control towers, the UNICOM frequency is used by the pilots use to talk to each other, usually 122.700, 122.800, 122.900, 123.000 or 123.050. Airports with control towers usually have an assigned Unicom channel of 122.950. Most airports large enough to have control towers have the following types of channels:
- ATIS (Automatic Terminal Information Service)- Weather, equipment failures, closed runways and taxiways, current operating runways, special notes, and NOTAM's.
- Clearance Delivery - The pilot uses this frequency to notify a controller of his flight intentions and to receive flight instructions and clearance for take-off.
- Ground Control - The ground controller tells the pilot which taxiways to use to arrive at the correct runway.
- Tower - The Tower Controller is responsible for the aircraft in the immediate area around the airport (Up to 3000 feet and 5 miles from the airport). Once the aircraft leaves the airspace of the airport, the pilot will be handed off to a controller at a TRACON(Terminal Radar Approach Control) or an ARTCC Center (Air Route Traffic Control Centers), commonly called Air Traffic Control).
- Approach Control(TRACON) - Directs several lines of descending aircraft into one smooth flowing line of aircraft as their courses take them closer to the destination airport.
- Departure Control(TRACON) - Routes air traffic immediately upon takeoff via a preferential departure route (PDR) leading away from the departure airport as the aircraft ascends to the en route phase of flight.
General Commercial Frequencies
118.000 - 121.400 Air Traffic Control (See AirNav)
122.000 - 123.650 Unicom, Flight Services, Traffic Advisory (CTAF) (See AirNav)
123.675 – 129.800 Air Traffic Control (See AirNav)
128.825 - 132.000 Company Airlines Operational Control
136.500 - 136.975 Company Airlines Operational Control
More specific info can be found at: Aircraft Frequencies
(See Note 1)
121.500 VHF Guard
243.000 Military UHF Guard
406.000 New Air Emergency (See Note 1)
Air to Air
Some of the more popular:
123.4500 Itinerant channel
122.7500 Fixed Wing
Domestic VHF/Operational Control ("Company Frequencies")
Aviation Spectrum Resources, Inc. (ASRI) is the spectrum manager for aeronautical "company frequencies" (128.825-132.0 and 136.5-136.975). ASRI licenses all the frequencies with the FCC and assigns them to other users, so unfortunately the FCC data only provides part of the story but it is a start. The primary users of these frequencies are airlines but they are also used by Fixed Base Operators (FBOs), corporate aviation bases, some medevac services and other entities.
Aeronautical Radio, Inc. (ARINC) used to be the spectrum manager for company frequencies but after a corporate reorganization, ASRI is now the spectrum manager. ARINC continues to operate a VHF radio network (the ARINC En Route Service) which is used mostly by smaller airlines to relay messages to their dispatchers or to establish phone patches.
There are no official "national" company frequency allocations, however among larger airlines there are common frequencies that you will find used by each at many different airports. Please note that "common" frequencies are less likely to be valid in busier air traffic areas due to frequency congestion (e.g., the northeast USA and mid-Atlantic USA regions). Some common allocations include:
128.925 Continental Connection 129.425 UPS 129.5 Delta 129.675 Continental Express 129.925 Continental 131.625 DHL 131.925 FedEx
There are several different uses for company frequencies by airlines:
- Dispatch - Many carriers have their own dispatch frequencies but some use the ARINC En Route Service instead as needed. Sometimes the Dispatch and Operations frequencies are the same at a given airport. Dispatch frequencies are used to contact the airline's dispatch staff which is usually located at the airline's headquarters. Dispatch frequencies are also used to contact maintenance staff at the airline's headquarters.
- Load Planning - Used by legacy carriers at the airline's hub airports.
- Maintenance - At airports where the airline has a large operation and/or a maintenance base, this frequency may be used to directly contact maintenance personnel at the airport.
- Operations - At an airline's non-hub airports, this is the main (and frequently the only) frequency used. This frequency is used by aircraft to contact the airline's local airport staff when "in range" and on the ground. Airlines will usually have an Operations frequency at their hub airports as well.
- Ramp Control - Used by large airline operations usually at hub airports. Certain ramp areas and some taxiways are designated as "non-movement areas" and are controlled by the airline's ramp controllers instead of airport's ground controller(s). Some or all of the ramp area may be under the control of Ramp Control. An airline's Ramp Control may control ramp areas used by other airlines.
When aircraft are within 20-30 minutes of their destination, they may call in on a company frequency to report equipment malfunctions, delays, rerouting, and the special needs, such as wheelchairs and unaccompanied minors (UM). Sometimes, when they are about 10 minutes off the ground on their trip away from the airport, they call back with the times they were off the gate, and off the ground. However, ACARS has replaced most of these communications.
Airlines with a small presence at a given airport will frequently contract out ground handling services to another airline, FBO or ground handling services company. In these cases, an airline may use the frequency of the entity that is handling them at the airport. But just to keep things interesting, some airlines will contract out ramp handling but have their own customer service staff so they may have their own company frequency in this case.
On the ground, you may find airline ground operations in the 460.65-460.9 MHz range. Often, you can learn of flight delays, cancellations, or gate changes on the 460 frequencies before they are announced. These frequencies are not listed at AirNav.
You may find a list of frequencies for the ARINC En Route Service on ARINC's website. They are kept on charts in PDF format, which is linked here.
You can also find other air-related frequencies used around a major airport by doing a Geographic Search for the latitude/longitude of your airport. Go to:
- FCC Geographic Search
- Enter the Lat/Lon of the airport (from AirNav)
- Enter radius of 1 Kilometer
- Hit the search.
Identifying Aircraft vs. Frequency
All commercial and private aircraft in the United States use callsigns that start with the letter 'N'. However, the ‘N-number’ is normally not used over the air for commercial flights. Private pilots and air traffic controllers often just use the last two or three digits of the callsign and the aircraft type to save precious air time ("Cessna 23-Hotel"). Commercial aircraft generally use the flight number and company name as their callsign ("United 152"). This can be confusing, but FlightAware will give you a list of possible flights with every combination of those numbers. For instance, if you enter ComAir 5650 in the Flight #, or COM5650 in the Flight/Tail #, you should be able to see that it is really ComAir #50. This will give you departure/arrival airports, and tracking if still enroute.
Another confusing area is the Codeshare. It refers to a practice where a flight operated by an airline is jointly marketed as a flight for one or more other airlines. For example, Delta has feeder airline partners with Comair, Chautauqua, Atlantic Southeast, etc. So Delta DL456, operated by ComAir, might be COM456, or even COM56. Flight Stats shows both. However, this does not always relate to what you heard. There are many other similar tracking sites, and they don’t always show the exact same thing, so it is good to use more than one.
Google Earth 3D tracking
With Google Earth installed on your PC, you can not only track one or several flights, but you can “rotate” the view when a plane is near an airport and see it actually descending or climbing. This is really neat! Download Google Earth free. Then go to FBOWeb General Apps or FBOWeb Specific Flights
Enter airline flight info, and click on the “Track in 3D” button. It will “install” the specific flight as a layer on Google Earth, and will also track aircraft in the general vicinity.
Identifying Frequency vs. Airport
When searching or monitoring the airport specific frequencies, such as Aproach/Departure, Clearance Delivery, Tower, ATIS, etc you can usually find out what airport you are hearing by typing airnav freq state, into a Google search box.
I.E. airnav 128.7 Pennsylvania
You can also go directly to the AirNav website and type in an airport name or identifier (Boston or KBOS).
- 121.500 (guard) Is commonly used to get the attention of an aircraft that has gone to the wrong frequency, or a VFR (non-ATC controlled aircraft) that is about to fly into a restricted area, as all aircraft are supposed to monitor guard if they have an available radio. The "satellite monitoring" eliminated in 2009 refers only to the emergency locator beacons (ELT's) that activate on 121.5/243MHz after a crash to aid in search & rescue operations. ELT's will still transmit their distinctive alarm on 121.5/243, but will only be heard by overflying pilots (if they are listening) and ground searchers with Direction-Finding (DF) equipment. New ELT's, while not required by the FAA, also transmit on 406MHz and can rely precise GPS coordinates of the downed aircraft. They also still transmit on 121.5 to alert other pilots, but the SARSAT system now only responds to 406MHz. 121.5 Guard continues to be used for voice communications, and remains the best and only way to get a hold on an aircraft not responding to other communications, or for a pilot to announce an emergency.
- Here is an Aviation Glossary that takes the mystery out of those abbreviations you hear.
- As with any service, there is a large number of specialized terms and phrases. See our Aviation Terminology article for more information
- Call Signs and Nicknames
- Corporate Trunked Systems includes trunked radio systems used by airline ground operations.
- Here’s some additional but slightly outdated info: