ELT or UEB
all people know DFDR includes ELT with 3 emergency freq built-in. When a/c in crash with a force of 5g for instant, the switch is gonna be active and make ELT works. The matter am in stuck is even when DFDR is under sea, how to allocate its location?
Some guys answered there is a UEB installed inside DFDR and active by water will help people finds exactly DFDR's location. OEB then transmits an ultrasonic freq
But I think with 3 above emergency freq, finding activities can be established without OEB to find exactly the place where DFDR is.
Whoever did research this plz help me.
thks