In a scenario where a pilot encounters an emergency situation on an aircraft, you may have seen in movies how they send out a distress signal “Mayday” over the radio. On the other hand, a less commonly known distress call “Pan-Pan” also exists. So, what are the differences between these two?
According to the aviation news website “Simple Flying,” the distinction between “Mayday” and “Pan-Pan” plays a crucial role in the aviation safety regulatory system. These regulations ensure that air travel remains one of the safest modes of transportation.
“Pan-Pan” is an emergency signal issued for potential dangerous situations that do not immediately threaten life. The crew typically handles such situations on their own for a period of time but may require priority handling or special assistance on the ground.
Using the “Pan-Pan” call can alert other aircraft and air traffic control (ATC) departments to cease non-emergency communications on that frequency, thereby giving the distressed aircraft priority. However, it does not trigger an immediate full-scale emergency rescue operation like the “Mayday” call does.
Similar to the use of “Mayday,” if a pilot declares an emergency situation, they must repeat the “Pan-Pan” call three times in the transmission.
Typical examples of situations warranting the use of the “Pan-Pan” call include the failure of a single engine, hydraulic system malfunctions, or electrical system issues that do not immediately affect flight capabilities. Despite safety concerns, pilots can still control the aircraft and have time for troubleshooting or altering the flight route.
Another situation may involve a sudden severe illness among passengers or crew members. While urgent, pilots can divert the aircraft to an appropriate airport for treatment by medical personnel awaiting at that airport.
In cases of fuel shortage, pilots can also use “Pan-Pan.” If the situation deteriorates further, pilots can escalate the call from “Pan-Pan” to “Mayday” at any time.
After a pilot issues a “Pan-Pan” distress signal, ATC personnel at the airport tower will immediately confirm the message and prioritize the aircraft’s flight over all other non-emergency flight tasks. They will also coordinate with the ground emergency rescue department promptly.
If pilots cannot establish radio contact immediately or need to inform all ATC units of their emergency situation, they may consider setting the transponder code to 7700 (the universal emergency transponder code).
Following the transmission of the “Pan-Pan” signal, pilots must send an emergency situation report, including necessary key information. The decision to send a “Pan-Pan” call rests with the captain of the aircraft.
The Federal Aviation Administration (FAA) in the United States encourages pilots to declare an emergency situation without hesitation if they have any doubts about flight safety.
When flight safety is severely threatened, pilots should issue a “Mayday” distress signal. Such situations include onboard fires or smoke, complete engine failure, structural damage, loss of control, and serious malfunctions in hydraulic or electrical systems.
Other applicable situations include imminent crashes or forced landings, insufficient fuel to reach a safe landing point, and emergencies requiring priority handling, such as severe medical emergencies necessitating immediate landing.
When the captain deems flight safety under threat and decides to declare an emergency situation by issuing a “Mayday” distress signal, the ATC department must prioritize handling and initiate emergency rescue operations upon receiving the signal.
A famous example is the “Miracle on the Hudson,” which occurred on January 15, 2009. During this incident, US Airways Flight 1549 suffered bird strikes, leading to both engines failing simultaneously and the aircraft losing all power.
Captain Chesley Sullenberger, after confirming the inability to reach any nearby airport, chose to conduct a forced landing on the Hudson River in New York. As a result, all 155 people on board survived, earning it the title of a miracle.