https://en.wikipedia.org/wiki/International_distress_frequency
121.5 MHz is the civilian aircraft emergency frequency or International Air Distress frequency. It is used by civilian distress radiobeacons; however, the Cospas-Sarsat system no longer monitors the frequency.
Un avion suisse du « quick reaction alert » (QRA) avec son bidon marqué STBY 121.50
Sur QRA en Suisse : http://airheadsfly.com/2015/12/02/swiss-hornets-start-qra-in-2016-on-weekdays/
Sur le QRA : https://en.wikipedia.org/wiki/Quick_Reaction_Alert
QRA par un Tornado et par un Typhoon
