ANC Headsets and Stall Warning Horns

kontiki

kontiki

Cleared for Takeoff
Joined
May 30, 2011
Messages
1,198
Display Name
Kontiki
Just curious how the CFIs are handling things with their ANC headsets in airplanes with already anemic stall warning horns.

I went back to my old Telex to go out in the PA-28 (Arrow III), just because I cannot heard the puny thing otherwise, and stall to Commercial PTS is first indication.
 
Have a pair of Lightspeed Zulus. No problem with hearing the stall horn in my 182. But then again maybe its because the stall horn is not anemic and I am not a CFI. :confused:
 
I have a pair of Bose and no problem as my stall warning yells at me in a loud voice.
 
Do you know that deaf pilots fly the same stuff we do?
 
That argument of not being able to hear warning horns or engine trouble with ANR has been false in my experiences, at least with my Zulu 1s.

As the others have alluded, you really don't need a horn to tell when a trainer is nearing a stall, let alone stalling. On that subject, my plane doesn't even have a stall horn or light.
 
I know I heard my stall horn a few days ago with my Zulu 2 with great ANR on...and it wasn't during training!
 
My airplane doesn't have a stall warning horn.
 
Every plane I have flown that has a stall horn, can be heard with or without an ANR headset. And if you can't hear the horn, it wouldn't be your first indication. ;)
 
kontiki said:
and stall to Commercial PTS is first indication.
Click to expand...

Someone please correct me if I'm wrong regarding PTS "standards", but the stall horn is NOT the "first indication" of a stall. It's calibrated to go off some margin over a stall. Some might say a fairly wide margin. First stall indication is a buffet or nose drop. You can fly all day long with the stall horn going off and not get any stall indication.
 
kontiki said:
Just curious how the CFIs are handling things with their ANC headsets in airplanes with already anemic stall warning horns.

I went back to my old Telex to go out in the PA-28 (Arrow III), just because I cannot heard the puny thing otherwise, and stall to Commercial PTS is first indication.
Click to expand...
It's not the ANR that makes it hard to hear stall or gear warning horns, it's the passive attenuation. ANR has no effect at frequencies above about 300 Hz and most horns have most of their significant spectrum higher than that. In most cases you can hear the horn better with the ANR turned on vs off because the ANR reduces the level of competing noise sources allowing your ears to be more sensitive to the horn's output.
 
My horn actually transmits through the audio panel...most of the time. I've never asked the avionics shop about this but I think it's an interference issue rather than by design, especially since it's intermittent.

I can still hear it fine when it doesn't.
 
Not an issue with my Lightspeed Zulu.2 headset, or any other I've tried including the Pilot 17-79's the Z2 replaced. ANR headsets focus on the low-frequency noise of the engine, and don't do near as much to filter out the high pitch of stall warning devices.
 
I have never seen them to be a problem with not hearing sounds.
 
Actually you can hear such things better with the ANR. I kept hearing a clanking sound with the headphone on that I could not when I lifted them off for a "better" hear. Turns out the weld broke in my exhaust.

Anyway, no stall horn in the Navion as there is a good warning buffet. I can hear the gear horn fine.
 
Is this possible? We have a clear consensus on a POA with no real diasagreement. Say its not true.
 
I hear the stall horn in the 172 on every landing through my Bose X's, no problem.
 
timwinters said:
My horn actually transmits through the audio panel...most of the time. I've never asked the avionics shop about this but I think it's an interference issue rather than by design, especially since it's intermittent.

I can still hear it fine when it doesn't.
Click to expand...
In a lot of airplanes the gear and/or stall horn will break the squelch on the intercom. I suspect that's what's been happening for you.
 
NineThreeKilo said:
That argument of not being able to hear warning horns or engine trouble with ANR has been false in my experiences, at least with my Zulu 1s.
Click to expand...

Agreed.
Additionally, I find that I can hear mechanical noises better with the low freqs and wind noise suppressed.

For example, last week the oil dipstick vibrated itself loose and started vibrating around. I could clearly hear it through my Bose X, the metallic rattle.
My wife, with PNRs, could not. I took my headset off, and could not hear anything over the engine and wind noise.
 
RoscoeT said:
Someone please correct me if I'm wrong regarding PTS "standards", but the stall horn is NOT the "first indication" of a stall. It's calibrated to go off some margin over a stall. Some might say a fairly wide margin. First stall indication is a buffet or nose drop. You can fly all day long with the stall horn going off and not get any stall indication.
Click to expand...

For CPL and ATP rides it's the horn 9 times out of ten.

If the nose droops you stalled, buffet you're right at a stall. The Feds want to see a pro pilot activly recognize and swiftly respond before that point, especially with paid pax onboard.
 
gismo said:
In a lot of airplanes the gear and/or stall horn will break the squelch on the intercom. I suspect that's what's been happening for you.
Click to expand...

That would make sense...never thought about that.
 
I could hear the 172 (slot on the left wing) and my Cheetah's horn (metal tab on the right wing) just fine through my DC ANR headset, and I'm deaf in my left ear.
 
timwinters said:
My horn actually transmits through the audio panel...most of the time. I've never asked the avionics shop about this but I think it's an interference issue rather than by design, especially since it's intermittent.

I can still hear it fine when it doesn't.
Click to expand...

gismo said:
In a lot of airplanes the gear and/or stall horn will break the squelch on the intercom. I suspect that's what's been happening for you.
Click to expand...

timwinters said:
That would make sense...never thought about that.
Click to expand...

Well, it was indeed a plausible theory but I discovered today that's not what's going on. I went flying today and practiced slow flight. Stall warning screaming away and being "broadcast" in my headset. So I covered up the mic with my hand and it was still being transmitted. So I pulled the headset's mic jack out of the panel. Still being transmitted.

Interesting.
 
NineThreeKilo said:
For CPL and ATP rides it's the horn 9 times out of ten.

If the nose droops you stalled, buffet you're right at a stall. The Feds want to see a pro pilot activly recognize and swiftly respond before that point, especially with paid pax onboard.
Click to expand...

I had to take my CPL to the buffet. CFI & private to the break (CFI was per examiner request). No issues. Never an issue with my Bose.
 
timwinters said:
Well, it was indeed a plausible theory but I discovered today that's not what's going on. I went flying today and practiced slow flight. Stall warning screaming away and being "broadcast" in my headset. So I covered up the mic with my hand and it was still being transmitted. So I pulled the headset's mic jack out of the panel. Still being transmitted.

Interesting.
Click to expand...
I don't suppose there were any other headsets plugged in? A horn does generate a fair amount of RF noise (it's kinda like a small spark gap transmitter) and it's possible that this could be coupling into the audio but I would expect that to sound quite a bit different than the horn itself.
 
gismo said:
I don't suppose there were any other headsets plugged in? A horn does generate a fair amount of RF noise (it's kinda like a small spark gap transmitter) and it's possible that this could be coupling into the audio but I would expect that to sound quite a bit different than the horn itself.
Click to expand...
Nothing else plugged in. I'm betting on interference of some sort...it sounds just like the horn...through the headset.
 
timwinters said:
Nothing else plugged in. I'm betting on interference of some sort...it sounds just like the horn...through the headset.
Click to expand...
If your intercom has manual squelch, turn that off (open mic) and see if the horn couples in with no mic's plugged in. If so, you might be able to shed some light on the problem by shorting each mic jack out, one at a time. If that stops the noise the wire to that jack is likely the one picking up the noise. I'd also make sure none of the mic jacks are grounded by their mounting.
 
Intercom = pse pma 7000 cd. No squelch.

Who said it was a problem? ;). It's kinda handy actually.

It's just an observation and just fine.
 
timwinters said:
Intercom = pse pma 7000 cd. No squelch.

Who said it was a problem? ;). It's kinda handy actually.

It's just an observation and just fine.
Click to expand...
Well, perhaps you'd want to make it less "intermittent" lest you come to rely on it and it doesn't happen?
 
You must log in or register to reply here.
Back
Top