"Scott Migaldi" wrote in message
...
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.

????

Juan
Never had this problem with my David Clarks or Lightspeeds. Could it be
that you have such a good ear seal that during descent the ear cups are
equalizing via a small amount of air leaking into them causing the squeal?
Have you tried loosening up the HS?

Scott

It's not me, it's a friend who flies Twin Otters out of Las Vegas. I sold
him a Denali ANR I was not using, and I had never flown with it to that high
of an altitude. He reported the problem, we talked to Flightcom, they asked
for it to be sent back and they changed the ANR module with one with an
adjustable sensitivity or something like that. They still don't know what
causes the squealing, though, and the change of modules doesn't always fix
the problem. Weird!

Juan