Antennas
Most aircraft have a number of antennas, but you know which antenna is which? In this lesson we do a walk around tour of your aircraft to help you identify each antenna and what function it serves. Photos are provided to aid in identification. Note: There are a number of hi-res photo on this page that may take a few seconds to minutes to fully load, depending on your link speed.
COM
For VHF voice communication. Transmit and receive. One antenna per transceiver. Usually found on the top of the fuselage, but sometimes one of them can be found on the belly of the aircraft. 118.0 - 137.0 MHz.
NAV
For VHF (VOR / LOC) navigation. Receive only. One antenna shared among receivers. Usually found near the top or middle of the vertical stabilizer and usually the antenna consists of two identical halves, one on each side of the vertical stabilizer. 108.0 - 118.0 MHz.
Note: This same antenna is also usually used to receive the UHF glideslope signal of an ILS. 329-335 MHz.
Transponder
For transponder information. Transmit and receive. One antenna per transponder (most aircraft only have a single transponder). Usually found on the belly of the aircraft. Receives on 1030 MHz, transmits on 1090 MHz, 978 MHz (ADS-B). Note: Transponder antennas and DME antennas can look almost identical (and they both come in the stubby wire and shark fin forms).
DME
For DME (Distance Measuring Equipment) functionality. Send and receive. Usually found on the belly of the aircraft. 962-1213 MHz (with cut-outs for other uses such as transponders and GPS L5). Note: Transponder antennas and DME antennas can look almost identical (and they both come in the stubby wire and shark fin forms). Also note that DME has been largely supplanted by GPS and it is very possible that your aircraft does not have a DME antenna.
GPS
For GPS location information. Receive only. Some aircraft have a single GPS antenna, others may have multiple GPS antennas. Usually found on the top of the aircraft, typically above the cockpit, but sometimes further back on the main fuselage. Frequencies: L1 (1575.42 MHz), L2 (1227.60 MHz), L5 (1176.45 MHz).
ELT
Emergency Locator Transmitter, activated either automatically or manually in the event of a crash or an off-field landing. Transmit only. Usually located on the top the the fuselage near middle or rear section. Older ELTs operate on 121.5 MHz, while newer ones operate on 406 MHz.
Marker Beacon
Receives the outer, middle, or inner marker beacon signals, which are used on some IFR approaches. Receive only. Usually found on the belly of the aircraft around the middle of the fuselage. Frequency: 75 MHz.
TAS - active Traffic Advisory System
For support of active-surveillance capability of Traffic Advisory Service (TAS). Transmit and receive. Usually found on top of the aircraft, but sometimes on the belly. This often is a dual-fin antenna, but it can also take other forms, such as a large block or disc, similar to a very large GPS antenna. Same frequencies as transponders. TAS is an expensive option, so it is not too common on training aircraft.
ADF/NDB
For receiving NDB (non-Directional Beacon) signals. Receive only. Note that some ADF receivers use a single "ADF Loop" antenna, while others use an "ADF Sense" antenna in addition to the "ADF Loop" antenna. The sense antenna, if included, is usually a wire run from atop the aircraft to the top of the tail. The main ADF antenna is usually found on the belly. These receivers can usually also receive traditional AM broadcast signals. Frequencies: 190-535 kHz for NDBs, AM Broadcast radio is 540-1600 kHz. Note that ADF receivers are relatively outdated technology and that fewer and fewer aircraft have them these days. It is very possible that your aircraft does not have an ADF antenna.