Juan Jimenez wrote:
Somebody explain to me why ANR headsets squeal when you are descending from
FL180 and lower in an unpressurized aircraft. Flightcom is modifying their
Denalis to deal with this but they say all ANR's do this.

Don't get up to FL180 much, but coming in to 23L at RDU, right next to the radar
antenna, I get a chirp on each revolution of the antenna. Happens on my Bose X
and my Telex ANR.

Dave