FAA paper Noise Attenuation Properties of Noise-Canceling Headsets

"Larry Dighera" wrote in message
.. .
[Possible audible alarm masking by ANR headsets warning snipped]

My old PA28-235 had a visual stall warning system, so there was no
issue there.

Given the fact that it is imperative to wear hearing protecting
headsets while operating most GA aircraft if you don't want to
permanently damage your hearing, perhaps it's time avionics
manufacturers provided warning indicator inputs to their audio panels.
Of course, such a system of providing audible alarms in the PIC's
headset would necessitate other equipment manufacturers providing the
necessary additional outputs.


On Tue, 09 Jan 2007 15:59:19 GMT, "Bill Denton"
wrote in
:

Have you looked at any modern audio panels?

No.

Both PS Engineering and Garmin provide 4 +/- unswitched auxiliary inputs...


That might be an adequate number of inputs in most cases, but it's
still going to require equipment manufacturers of stall warning
systems, autopilots, etc to provide the audio outputs in addition to
their horns and bells.

Larry Dighera wrote:

That might be an adequate number of inputs in most cases, but it's
still going to require equipment manufacturers of stall warning
systems, autopilots, etc to provide the audio outputs in addition to
their horns and bells.

Have you ever used an ANR headphone? Most don't attentuate
frequencies that the various alarms (my gear alarm, the cessna
stall party horn, etc...) much more than the passive headphones
do.

Even engine noises are frequently enhanced by ANR. I kept hearing
a clanking noise in the ANR. I pulled off my headphones for a "better
listen" and couldn't hear it. With the ANR I heard it. On landing
I found my exhaust pipe had busted a weld and was flapping around.

On Tue, 09 Jan 2007 12:34:25 -0500, Ron Natalie
wrote in :

Larry Dighera wrote:

That might be an adequate number of inputs in most cases, but it's
still going to require equipment manufacturers of stall warning
systems, autopilots, etc to provide the audio outputs in addition to
their horns and bells.

Have you ever used an ANR headphone?

Yes. Exclusively since 1996.

Most don't attentuate frequencies that the various alarms (my gear alarm,
the cessna stall party horn, etc...) much more than the passive headphones
do.

Even engine noises are frequently enhanced by ANR. I kept hearing
a clanking noise in the ANR. I pulled off my headphones for a "better
listen" and couldn't hear it. With the ANR I heard it. On landing
I found my exhaust pipe had busted a weld and was flapping around.

Well, that's your experience. It's a data point for sure, but not a
comprehensive study.

If the FAA has found issues as a result of the popularity of ANR
headsets, who am I to dispute it. Certainly most legacy alarms were
tested and approved for use before ANR technology existed, hence my
suggestion for "piping" alarms into the headphone audio in addition to
the ambient cockpit environment.

Larry,

If the FAA has found issues as a result of the popularity of ANR
headsets,


I don't think it says that anywhere in that INFO. It says us pilots
should go and find out.

--
Thomas Borchert (EDDH)

Ron Natalie wrote:

Even engine noises are frequently enhanced by ANR. I kept hearing
a clanking noise in the ANR. I pulled off my headphones for a "better
listen" and couldn't hear it. With the ANR I heard it. On landing
I found my exhaust pipe had busted a weld and was flapping around.

I was able to hear a starter that was stuck engaged WITH the ANR set on.
The sound was not audible by my companion pilot with a non-ANR set, or
me with the headset removed.

The sound was not audible by my companion pilot with a non-ANR set, or
me with the headset removed.

This fits 100% with our experience as well. ANR headphones *enhance*
hearing, and certainly cannot mask the sound of any stall horn/buzzer.
With our Lightspeed Twenty3Gs, we routinely hear things that are
completely inaudible (lost in the noise, actually) without them.

I remember a flight to OSH when we kept hearing a weird whooshing
noise. We were throttled way back to 20 squared, to stay in loose
formation with a slower plane -- something we had rarely done before.
The noise continued, and we simply couldn't figure out what it was.

After a few minutes it finally dawned on us: We were hearing the wind
as it rushed over the fuselage.

Try THAT without ANR headsets!
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Jay Honeck wrote:


I remember a flight to OSH when we kept hearing a weird whooshing
noise. We were throttled way back to 20 squared, to stay in loose
formation with a slower plane -- something we had rarely done before.


You were talking the other day about all the money you save with mogas.
At 20 squared I am indicating about 160 mph in the winter and about
150-155 in the summer, burning 8-8.5 GPH, which for me is about 50 LOP.
What's your speed and fuel burn there?

You were talking the other day about all the money you save with mogas.
At 20 squared I am indicating about 160 mph in the winter and about
150-155 in the summer, burning 8-8.5 GPH, which for me is about 50 LOP.
What's your speed and fuel burn there?

SLOOW. At 20 squared, we were hanging on the prop, trying to fly
formation with our old Warrior -- so probably around 115 knots. Fuel
burn is about the same, though -- maybe 8.5 GPH.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"