Mine has not had operational tests as it is in the covering stage of the rebuild. I don't have to worry about airworthiness because my airplane already has one since it is a rebuild project. Before I got it there was a AmeriKing AK450 ELT in it and I opted for the Artek ELT 345. I have read reports that they work fine inside the fuselage. I figure it will be better than the iffy AK450. Will be testing when its warmer though.