Maybe it's necessary over there, but in the U.S. it isn't even useful. There are no beacons offshore, and fewer every day inland. If I lose my GPS, I still have 2 (count 'em, 2) VOR's. If I lose all these, I still can't use the ADF for much, because there are no ADF approaches near the beach. I can, however, fly north until ATC can hear me, & get a radar approach at many airports. The ADF costs money to install, & much more to maintain. Our avionics techs spend a lot of time fixing them, & replacing parts. That money could be much, much better spent on something more useful & more likely to save my butt, like TCAS or another GPS or almost anything. I have in my shirt pocket a computer more powerful than what is on the space shuttle, & it cost less than $US300. Technology moves on, & old technology becomes obsolete. Get over it.