Aug
29
An aircraft needs to dump fuel so the ATC kept saying something along the lines of “Toronto Tower transmitting on guard, warning to all aircraft not on an ATC clearence Boeing 727 is dumping fuel etc. etc.” And why would they choose to use 121.5 as the frequency? Who is listening to that frequency?
Answer:
121.5 is the emergency frequency. If you need to transmit a distress signal, you are supposed to transmit it over 121.5 if you aren’t in contact with ATC. ELT’s (emergency locator transmitters) also emit a signal on this frequency when an aircraft is involved in an accident to alert someone that there may be a plane crash and also help in locating the aircraft. This frequency was monitored up until a few months ago by flight service employees and certain air traffic control facilities. Pilots are also requested to monitor, or guard, this frequency and notify ATC if they hear a distress call or ELT signal.