"Juan Jimenez" wrote in message
...

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


I have Lightspeed 25XL2's.... never had that problem with them, do get some
interesting bleeds tho when on an ILS/LOC/BC approach, hear a periodic
buzzing sound coming down the glideslope, and another one when abeam the
localizer antannae on a circle to land, its never all that loud, just
noticable. Never taken the headset above 13k, so don't know if altitude is
a big factor on the squeal, but i've done drop like a rock descents numerous
times and it hasn't fazed the elctronics a bit. Only beef I've had with my
headset was the origonal mic went out after a year of use, shortly after i
started the plane up for my CPSE checkride, DE let me run home and get my
backup set (had already done one discontinuance for weather). Lightspeed
was very prompt in sending me a new mic and installation instrucitons,
overall pleased with the headset, and i've tried others. Anyway kind of
rules out the "ALL ANR's do this" argument. Be curious to hear what causes
that particular squeal in the Denali's, I've never thought altitude would
make a difference on how ANR works, other than lower air density at higher
altitudes (would that screw ANR up that badly tho?).