Käitatav õhusõiduk, välja arvatud ülikerglennuk, purilennuk, motopurilennuk, õhulaev ja kuumaõhupall, peab olema varustatud sagedustel 121,5 ja 406 MHz töötava avariimajakaga (emergency locator-transmitter – ELT), mille parameetrid vastavad 1944. aasta Chicago rahvusvahelise tsiviillennunduse konventsiooni lisa 10 köite III nõuetele.
An ELT may be any of the following: Automatic fixed ELT (ELT(AF)). An ELT which is permanently attached to an aircraft. Automatic portable ELT (ELT(AP)). An ELT which is rigidly attached to an aircraft but readily removable from the aircraft after a crash. Automatically deployable ELT (ELT(AD)). An ELT which is rigidly attached to an aircraft and deployed automatically in response to a crash. Manual deployment is also provided. Survival ELT (ELT(S)). An ELT which is removable from an aircraft, stowed so as to facilitate its ready use in an emergency and activated by survivors. Automatic activation may apply.
