Avionics failure yesterday...

[[email protected]]

Well, I haven't posted here in quite awhile. I'm an IFR-rated PP with
about 400 hours currently. Lately flying about 8 hours a month on
average.

Had an interesting experience yesterday: a "hard" avionics failure
complete with something popping/blowing/burning. Flying a very nice,
new (2000) rented 172SP, there was a pop, the audio panel went dead,
and then an acrid odor in the cabin.

After the couple seconds of stark surprise I flipped the avionics
master off. When it appeared there was no real smoke and the smell
disappated I tried cycling the master. Nothing bad, but no audio panel
(completely dead) and thus no radios.

I had just traversed a class C area and was still on with approach when
losing the stack. I also happened to be damned near over an
uncontrolled field (a generally busy one though approach had called out
no traffic and none was visible in the pattern 1000' or so below me).
I decided that I should really land there and pulled the throttle out.
#1, home field is controlled and I had no radios. #2, since something
had definitely 'burned' under that panel, I wanted the airplane on the
ground.

Of course I couldn't get the WX there with no radios. Airport has a
4/22 and 14/32. Local winds were generally N-NW. After a slow 180 to
lose alt I was more or less lined up with 4 and decided that would
work. However, on short final I noted that I was crabbing a good 30d
and was high as well, though I could have lost the remaining alt with a
slip and full flaps easily enough. However, since though I was now
NORDO it was not an emergency situation, I decided to do a climing 270
turn into 32, which I did, and was on the ground pretty quickly, all
the while looking around everywhere for traffic (none).

Taxied to the FBO and grabbed a car back to home airport (45 minute
drive - was on local sightseeing flight with a coworker and
girlfriend).

Overall, in retrospect, I was largely happy with my performance as I
didn't panic or anything of that sort (inexcusable) and got the
aircraft on the ground pretty quickly. However, I should have done at
least one thing differently: I should have either left the avionics
master off or, if leaving it on as I did once determining there was no
danger, I should have squawked 7600. I never changed my squawk. I
elected to leave the panel on mainly to give ATC the benefit of my
return, being right on the border of their airspace, and didn't change
the squawk because I didn't really think of it. Priority was landing
and getting out of the airplane.

Oh, I'd also verified the extinguisher on board and had it at the
ready.

Haven't heard back from the owner yet (local FBO) but I'd imagine a
resistor or cap in the audio panel itself went. No breaker had popped
(the audio panel doesn't have its own breaker).

Lessons learned:

1) ALWAYS have handheld with me. I own one - I'd left it in my own
152, which is what I usually fly. Nothing but laziness in not taking
it with me. (What could go wrong on a short, local flight, after
all?!)

2) Take a bit of time to think about a squawk in any lost-comm
situation. Really, it would have taken 5s to change the squawk and I
had plenty of time.

Would welcome any comments on the experience.

[Peter R.]

> wrote:

> Would welcome any comments on the experience.

A couple of thoughts:

Perhaps call the ATC facility that was last handling your aircraft once on
the ground and explain to them what happened?

or, use your cell while in the air to call FSS to relay a msg to ATC?

--
Peter

[Ron Natalie]

wrote:

>
> Of course I couldn't get the WX there with no radios. Airport has a
> 4/22 and 14/32.

That's what windsocks are for.

> However, since though I was now
> NORDO it was not an emergency situation,

NORDO is not an emergency. Burning stuff IS however.

>
> Overall, in retrospect, I was largely happy with my performance as I
> didn't panic or anything of that sort (inexcusable) and got the
> aircraft on the ground pretty quickly. However, I should have done at
> least one thing differently: I should have either left the avionics
> master off or, if leaving it on as I did once determining there was no
> danger, I should have squawked 7600.

Without being IFR or someplace like a class B where communications with
a radar controller is required, I wouldn't bother sqawking IFR. If I
thought things might still be burning I would have left the avionics (or
general) master off.

In flight fires are nothing to sneeze at. The fire potential is a
much bigger issue than the nuisance of having no radios VFR. ATC
can fend for themselves.

> 1) ALWAYS have handheld with me. I own one - I'd left it in my own
> 152, which is what I usually fly. Nothing but laziness in not taking
> it with me. (What could go wrong on a short, local flight, after
> all?!)

And make sure it has alkalines or some other non-self-discharging
batteries in it. Nothing like finding the nicads in your handheld are
dead when you need it in such a situation.

>
> 2) Take a bit of time to think about a squawk in any lost-comm
> situation. Really, it would have taken 5s to change the squawk and I
> had plenty of time.
>
There's no real point to it in this case.

Glad it all worked out for you.

[Jose[_1_]]

> Would welcome any comments on the experience.

I think you did fine.

You had a landing you could walk away from, and the airplane is
reusable. :)

> When it appeared there was no real smoke and the smell
> disappated I tried cycling the master. Nothing bad, but no audio panel
> (completely dead) and thus no radios.

At first I read this as the master, but I think you meant the avionics
master. Did any radio lights come on? Did the transponder do its
transponder blikey thing?

I had an alternator failure once, at night over water coming back from
Block Island with a full passenger load (four in all). In retrospect I
should have tried cycling the master (I may have actually tried that; I
don't remember). My first response was to turn things off to conserve
the battery, and to reassure the passengers that the engine would keep
running without electricity and we were perfectly fine. I considered
what drew the most juice and what gave me the most bang for my buck, and
settled on one comm radio, the strobes (which I later turned off), and
the transponder. I told ATC (I had flight following) what had happened
and what I was doing, they were fine with that. ("are you declaring an
emergency?" "no, not at this time").

The front seat passenger startd to feel a little queasy, so I managed to
get the air vent pointing right at him, which helped a lot.

They asked my intentions, which were to continue on to Danbury, and that
I'd be turning the transmitter off. I remember they asked other
questions, getting my response via squawking ident on the transponder,
then halfway across the Sound I turned the transponder off, figuring
they had me on primary, and knew where I was going anyway. It was a
clear and a million night, so I flew to Danbury, turned on the radio to
contact the tower and landed uneventfully.

My friends were very impressed. I guess it doesn't take all that much,
but knowing that the engine would keep turning is key.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

[Roy Smith]

wrote:
> Overall, in retrospect, I was largely happy with my performance as I
> didn't panic or anything of that sort (inexcusable) and got the
> aircraft on the ground pretty quickly. However, I should have done at
> least one thing differently: I should have either left the avionics
> master off or, if leaving it on as I did once determining there was no
> danger, I should have squawked 7600. I never changed my squawk. I
> elected to leave the panel on mainly to give ATC the benefit of my
> return, being right on the border of their airspace, and didn't change
> the squawk because I didn't really think of it. Priority was landing
> and getting out of the airplane.

Sounds like you did everything right. Don't beat yourself up nit-picking
some minor detail that you might have done differently.

If you had no radios, what makes you think the xponder was working? And,
more to the point, even if it was, what do you think would have happened
any differently if you squawked 7600?

> 2) Take a bit of time to think about a squawk in any lost-comm
> situation.

That is certainly true, but more generally, once you've determined that
there's no immediate danger in any abnormal situation, take the time to
think. As long as the engine's still turning, the wings are still
attached, and you're not on fire, you've got time to take stock of what's
happening and figure out a plan.

[Jim Macklin]

A headset will still work, even though the speakers won't.
You'll have to set volume controls.


> wrote in message
ups.com...
| Well, I haven't posted here in quite awhile. I'm an
IFR-rated PP with
| about 400 hours currently. Lately flying about 8 hours a
month on
| average.
|
| Had an interesting experience yesterday: a "hard" avionics
failure
| complete with something popping/blowing/burning. Flying a
very nice,
| new (2000) rented 172SP, there was a pop, the audio panel
went dead,
| and then an acrid odor in the cabin.
|
| After the couple seconds of stark surprise I flipped the
avionics
| master off. When it appeared there was no real smoke and
the smell
| disappated I tried cycling the master. Nothing bad, but
no audio panel
| (completely dead) and thus no radios.
|
| I had just traversed a class C area and was still on with
approach when
| losing the stack. I also happened to be damned near over
an
| uncontrolled field (a generally busy one though approach
had called out
| no traffic and none was visible in the pattern 1000' or so
below me).
| I decided that I should really land there and pulled the
throttle out.
| #1, home field is controlled and I had no radios. #2,
since something
| had definitely 'burned' under that panel, I wanted the
airplane on the
| ground.
|
| Of course I couldn't get the WX there with no radios.
Airport has a
| 4/22 and 14/32. Local winds were generally N-NW. After a
slow 180 to
| lose alt I was more or less lined up with 4 and decided
that would
| work. However, on short final I noted that I was crabbing
a good 30d
| and was high as well, though I could have lost the
remaining alt with a
| slip and full flaps easily enough. However, since though
I was now
| NORDO it was not an emergency situation, I decided to do a
climing 270
| turn into 32, which I did, and was on the ground pretty
quickly, all
| the while looking around everywhere for traffic (none).
|
| Taxied to the FBO and grabbed a car back to home airport
(45 minute
| drive - was on local sightseeing flight with a coworker
and
| girlfriend).
|
| Overall, in retrospect, I was largely happy with my
performance as I
| didn't panic or anything of that sort (inexcusable) and
got the
| aircraft on the ground pretty quickly. However, I should
have done at
| least one thing differently: I should have either left the
avionics
| master off or, if leaving it on as I did once determining
there was no
| danger, I should have squawked 7600. I never changed my
squawk. I
| elected to leave the panel on mainly to give ATC the
benefit of my
| return, being right on the border of their airspace, and
didn't change
| the squawk because I didn't really think of it. Priority
was landing
| and getting out of the airplane.
|
| Oh, I'd also verified the extinguisher on board and had it
at the
| ready.
|
| Haven't heard back from the owner yet (local FBO) but I'd
imagine a
| resistor or cap in the audio panel itself went. No
breaker had popped
| (the audio panel doesn't have its own breaker).
|
| Lessons learned:
|
| 1) ALWAYS have handheld with me. I own one - I'd left it
in my own
| 152, which is what I usually fly. Nothing but laziness in
not taking
| it with me. (What could go wrong on a short, local
flight, after
| all?!)
|
| 2) Take a bit of time to think about a squawk in any
lost-comm
| situation. Really, it would have taken 5s to change the
squawk and I
| had plenty of time.
|
| Would welcome any comments on the experience.
|

[Roy Smith]

Jose > wrote:
> I had an alternator failure once, at night over water coming back from
> Block Island with a full passenger load (four in all). In retrospect I
> should have tried cycling the master (I may have actually tried that; I
> don't remember). My first response was to turn things off to conserve
> the battery, and to reassure the passengers that the engine would keep
> running without electricity and we were perfectly fine.

So far, so good.

> I considered
> what drew the most juice and what gave me the most bang for my buck, and
> settled on one comm radio, the strobes (which I later turned off), and
> the transponder. I told ATC (I had flight following) what had happened
> and what I was doing, they were fine with that. ("are you declaring an
> emergency?" "no, not at this time").

Again, so far so good.

> The front seat passenger startd to feel a little queasy, so I managed to
> get the air vent pointing right at him, which helped a lot.
>
> They asked my intentions, which were to continue on to Danbury

Now I'm starting to think there was a bit of get-home-itis going on. I
don't know what you were flying, but BID to DXR is the better part of an
hour in most spam cans. You were going to overfly a half-dozen towered
airports where you could find repair services and rental cars during that
time.

How did you know you were going to still have enough battery in a half hour
to work the radio? Maybe before the alternator went off-line, it hadn't
been charging the battery very well for quite a while and you had a lot
less battery time than you thought you did.

How do you know it was the alternator itself which was at fault, and not
some short somewhere which knocked the alternator off-line and was
continuing to drain the battery?

I know you said it was "clear and a million", but I can tell you from
experience that at night, you probably won't know there's a cloud in the
sky until you find yourself inside it.

DXR has a part-time tower. What if you got there after the tower closed
and didn't have any working radio to turn the runway lights on? DXR is
surrounded by high terrain. Not the kind of place I'd like to be trying to
find a runway in the dark.

You've already got a pax who's not feeling well. What were you going to do
if "a little queasy" suddenly turned worse and you had no working radio to
tell ATC that you needed priority handling at the nearest airport due to an
ill passenger?

Day-VFR by yourself, an alternator failure should be a complete non-event.
At night, it becomes a bit more of an issue. With non-pilot pax (who are
YOUR responsibility), I'd be thinking much more conservatively. With one
of the pax not feeling well, I'd be thinking getting on the ground at the
first reasonable opportunity.

[Jose[_1_]]

> Now I'm starting to think there was a bit of get-home-itis going on. I
> don't know what you were flying, but BID to DXR is the better part of an
> hour in most spam cans. You were going to overfly a half-dozen towered
> airports where you could find repair services and rental cars during that
> time.

That's correct. However, there was nothing critical to repair. The
alternator tripped, that's all. The engine's still turning, the
weather's severe clear (albeit night), plenty of gas; I saw nothing of
any urgency. Even if the battery totally died, I could circle Danbury
and get a light gun. If Danbury closed (I think this was before PCL, I
don't remember) I could just come in... and if I needed runway lights, I
could divert to another airport if necessary. So far, no urgency, but
I'm keeping tabs on things. And so is ATC, even if it's just a primary
target.

> You've already got a pax who's not feeling well. What were you going to do
> if "a little queasy" suddenly turned worse and you had no working radio to
> tell ATC that you needed priority handling at the nearest airport due to an
> ill passenger?

"little queasy" was not a medical emergency. He was nervous and a
little airsick - no more. It went away quickly once he got some cool
air on him. (Had it been more, I would have alerted ATC, and if that
were no longer possible, I would have simply diverted.)

> With one
> of the pax not feeling well, I'd be thinking getting on the ground at the
> first reasonable opportunity.

.... and then what?

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

[Emily[_1_]]

Jose wrote:
<snip>
>
> "little queasy" was not a medical emergency.

Never had a pax throw up on you, huh?

[Jose[_1_]]

> Never had a pax throw up on you, huh?

Not when I was unprepared. :)

I fly pipers now. I guess I like to live dangerously.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

[Roy Smith]

Jose > wrote:
> That's correct. However, there was nothing critical to repair. The
> alternator tripped, that's all. The engine's still turning, the
> weather's severe clear (albeit night), plenty of gas; I saw nothing of
> any urgency. Even if the battery totally died, I could circle Danbury
> and get a light gun.

With a dead battery, you'd not only have no radio, but also no lights and
no transponder. What makes you think the tower would even have a clue you
were there?

>> With one of the pax not feeling well, I'd be thinking getting on the
>> ground at the first reasonable opportunity.

> ... and then what?

Get the airplane fixed and/or rent a car to get your pax home.

[Emily[_1_]]

Roy Smith wrote:
> Jose > wrote:
>> That's correct. However, there was nothing critical to repair. The
>> alternator tripped, that's all. The engine's still turning, the
>> weather's severe clear (albeit night), plenty of gas; I saw nothing of
>> any urgency. Even if the battery totally died, I could circle Danbury
>> and get a light gun.
>
> With a dead battery, you'd not only have no radio, but also no lights and
> no transponder.

I was wondering if I was the only one who noticed that. I've only had
one complete avionics failure, and it of course affected the transponder
as well. We put it on 7600 in case everything came back on, but
thankfully the radios stayed on long enough that tower knew our
intentions...and long enough that we got yelled at for not having a
transponder on... :-)

[Jose[_1_]]

> With a dead battery, you'd not only have no radio, but also no lights and
> no transponder. What makes you think the tower would even have a clue you
> were there?

They were expecting me. I had already told ATC my intentions. I'd be a
primary target until I dropped below radar. I've landed without lights
before, it's no big deal. Had I not been able to get landing lights,
then I might have needed to divert to an airport that had them. But if
the failure were one that would drain the battery before I got to
Danbury (it was about twenty minutes away tops), it would likely have
drained no matter where I picked. I think the nearest airport was New
Haven or Bridgeport; DXR isn't much further.

> I was wondering if I was the only one who noticed that.

I noticed that, at the time. In fact, since I turned off the lights and
the transponder, I was already in that state. I just had to be extra
vigilant.

>>... and then what?
> Get the airplane fixed and/or rent a car to get your pax home.

I suppose. But yanno, everything is risk for benefit. The additional
risk of continuing with no alternator at night for about fifteen minutes
was one I judeged acceptable for the benefit of not having to deal with
hours of hassle.

It's not like a crash was imminent, or even likely.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

[Jose[_1_]]

> Had I not been able to get landing lights

I meant runway lights.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

[[email protected]]

> That's what windsocks are for.

I don't believe a fly-over was a good choice in the situation, Ron.

> NORDO is not an emergency. Burning stuff IS however.

Right. Question was, *was* there something burning, or smoldering, or
no? As more time went by with no further signs, the "no" became
reinforced.

My experience with electronics (limited) made me think it was a cap or
resistor that went, in which case no more circuit and no real fire
danger.

> In flight fires are nothing to sneeze at. The fire potential is a
> much bigger issue than the nuisance of having no radios VFR. ATC
> can fend for themselves.

In retrospect, I agree with you, in that I should have just turned the
master off and left it there.

> And make sure it has alkalines or some other non-self-discharging
> batteries in it. Nothing like finding the nicads in your handheld are
> dead when you need it in such a situation.

Yeah, I recharge them twice monthly.

> There's no real point to it in this case.

Glad you agree with that.

> Glad it all worked out for you.

Thanks. In reality, it was not a big deal. It's what it could have
been had there actually been a fire.

[[email protected]]

I
Peter R. wrote:
> > wrote:
>
> > Would welcome any comments on the experience.
>
> A couple of thoughts:
>
> Perhaps call the ATC facility that was last handling your aircraft once on
> the ground and explain to them what happened?
>
> or, use your cell while in the air to call FSS to relay a msg to ATC?

I tried to call the TRACON but could not find the number. I know
they're somewhere! So I called the tower, only number I could get, and
left a short message with a plea to relay it. No call back.

>
> --
> Peter

[[email protected]]

> At first I read this as the master, but I think you meant the avionics
> master. Did any radio lights come on? Did the transponder do its
> transponder blikey thing?

It was the avionics master, yes. Everything but the audio panel came
back on - the radio were just fine, but with a dead audio panel there's
no way to use them!

[Jose[_1_]]

> Everything but the audio panel came
> back on - the radio were just fine, but with a dead audio panel there's
> no way to use them!

Well... maybe. I agree you did the right thing, but in a different
situation, where you needed to communicate, there might have still been
a way.

If you key the mike, does the TX light up? You could go to 121.5 and
use morse code. Clumsy, but possible in a true emergency, so long as
you don't get distracted by it.

It might be that they can hear you but you can't hear them. Ask a tower
for a light gun signal - see if you get it. That will let you know
they can hear you (or not). You could at least say intentions if you
were in more dire straits.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

[[email protected]]

wrote:
> Flying a very nice, new (2000) rented 172SP, there was a pop, the
> audio panel went dead, and then an acrid odor in the cabin.

If it turns out to be the panel that failed, and depending on the
warranty policies of the panel manufacturer, it might be interesting
if the aircraft owner can get a local tech to open up the panel.
This is within the date range of a big batch of bad capacitors; they
are most famous for failing on PC motherboards, but they have turned
up in lots of places: http://en.wikipedia.org/wiki/Capacitor_plague

> After the couple seconds of stark surprise I flipped the avionics
> master off. When it appeared there was no real smoke and the smell
> disappated I tried cycling the master. Nothing bad, but no audio
> panel (completely dead) and thus no radios.

Disclaimer: This is based on very limited experience with audio panels
(real panels, but installed in simulators) a few years back. I thought
some panels had a default "bypass" mode. In other words, under certain
conditions, it connects the pilot's earphones/mic/PTT to COM 1 and
that's it. You don't get an intercom or the Dolby 5.1 surround from
the DVD player or anything else, but you can use one of your radios.

The way to get into this mode probably varies. Simply shutting off the
audio panel might do it. If the "bypass" is implemented with an
electromechanical relay, it should even still work under many of the
failure conditions of the audio panel - if the power to the relay coil
drops out, the contacts will make the default connection. On an older
panel with the "only one at a time" mechanical switches on the front,
pushing one of the switches in halfway and then releasing so that none
of the switches are pressed might do it. The manual (or careful
experimentation) may help.

If audio panels _don't_ do this, or if the old ones did but the new
ones don't, I wonder if it would be useful to have a headset jack that
connects directly to COM 1 and doesn't go through the audio panel. That
way, if you lose the panel but not the radio, you can plug your headset
into the "direct" jack and still use COM 1. I realize you don't get to
add your own jacks to a rental plane - this is more of a general "would
this be useful" question.

> 1) ALWAYS have handheld with me.

A couple of people have mentioned having good batteries in it as well.
If you want to be able to just pick up the handheld and talk, this may
not work very well. Also, none of this stuff is as critical as a backup
radio in an airplane. Having said that, I have a couple of portable
devices that I run NiMH AA batteries in. What I do is to have a couple
of sets of NiMH and a fresh set of alkalines. If I go through both sets
of NiMH, I can then put in the alkalines while I decide what to do next.
The alkalines don't mind sitting around for a few months doing nothing,
and if I haven't used them after several months, I'll use them somewhere
else and get a fresh spare set of alkalines for the portables.

Matt Roberds

[Bill Denton]

With most modern audio panels, when they fail, you still have a connection
to the mic and headset jacks on the #1 COM. You can test this by simply
turning the audio panel "off" and seeing if the #1 COM works.

I have also heard of aircraft that have a "backup" set of jacks that are
directly connected to the #1 COM, bypassing the audio panel entirely.

It might be worth a little time to fully familiarize yourself with the
various audio panels you might encounter....



> wrote in message
oups.com...
> > At first I read this as the master, but I think you meant the avionics
> > master. Did any radio lights come on? Did the transponder do its
> > transponder blikey thing?
>
> It was the avionics master, yes. Everything but the audio panel came
> back on - the radio were just fine, but with a dead audio panel there's
> no way to use them!
>

[Roy Smith]

In article >,
Jose > wrote:

>
> If you key the mike, does the TX light up? You could go to 121.5 and
> use morse code. Clumsy, but possible in a true emergency, so long as
> you don't get distracted by it.

OK, all you controller types out there -- what are the odds that anybody on
121.5 would know enough code these days to have a clue what was being sent
(or even recognize it as anything but a bunch of annoying clicking noises).

[Ron Natalie]

wrote:

>
> Thanks. In reality, it was not a big deal. It's what it could have
> been had there actually been a fire.
>

I had a similar thing once. I had just pulled my plane out of the shop
where they had worked on the voltage regulator. I don't know if it was
just my imagination or what but I was sure as I was climbing out I
smelled electrical smoke and thought I might have detected some
visually. I keyed the mike and told the tower I was coming back and
shutting off the master now. I did, and as I am on short final
I notice the entire Air National Guard crash and rescue brigade
racing to the approach end of the runway. Oh well, better safe
than sorry, I just hope they don't drown me in foam before I can
get out of the aircraft.


I mention the batteries because I once was a passenger in a IFR
(but VMC) NORDO plane and the pilot's hand held batteries were
also moribund. I did manage to get clearance to land at Dulles
with only the receiver working.

[Ron Natalie]

Roy Smith wrote:
> In article >,
> Jose > wrote:
>
>> If you key the mike, does the TX light up? You could go to 121.5 and
>> use morse code. Clumsy, but possible in a true emergency, so long as
>> you don't get distracted by it.
>
> OK, all you controller types out there -- what are the odds that anybody on
> 121.5 would know enough code these days to have a clue what was being sent
> (or even recognize it as anything but a bunch of annoying clicking noises).

Not sure they'd recognize morse code, but that doesn't mean that can't
be an effective means of communications. If you were still on the
original approach frequency, the controller might guess who it was
and say:

N5327K if that is you trying to transmit click the mike twice.

and so forth to ask simple questions about what you wanted to do.

The time we lost all electrical but I had effectively a receive-only
handheld radio, they issued turn instructions to us for identification
and to inquire about our intentions.

[[email protected]]

> If you key the mike, does the TX light up? You could go to 121.5 and
> use morse code. Clumsy, but possible in a true emergency, so long as
> you don't get distracted by it.

No, it didn't. There was no transmit and no receive. I assumed that
when I said "the radios were dead" I didn't need to explain further.

IF the transmit light was going on, and I DID know a bit of morsecode,
it might have been worthwhile to pound out a few letters, but just
barely. What I should have done, as I said, is squawk 7600.

[Ross Richardson[_2_]]

wrote:
>
> Lessons learned:
>
> 1) ALWAYS have handheld with me. I own one - I'd left it in my own
> 152, which is what I usually fly. Nothing but laziness in not taking
> it with me. (What could go wrong on a short, local flight, after
> all?!)
>
> 2) Take a bit of time to think about a squawk in any lost-comm
> situation. Really, it would have taken 5s to change the squawk and I
> had plenty of time.
>
> Would welcome any comments on the experience.
>

Be sure you have a head set adapter. Handhelds are very hard to use with
all the noise. I have one.
--

Regards, Ross
C-172F 180HP
KSWI

[Mxsmanic]

Ron Natalie writes:

> I mention the batteries because I once was a passenger in a IFR
> (but VMC) NORDO plane and the pilot's hand held batteries were
> also moribund. I did manage to get clearance to land at Dulles
> with only the receiver working.

Lithium batteries will hold their charge for a decade at least. They
are also very light, and they provide high current on demand. I use
them exclusively for everything when I have the option.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Ron Natalie]

Mxsmanic wrote:
> Ron Natalie writes:
>
>> I mention the batteries because I once was a passenger in a IFR
>> (but VMC) NORDO plane and the pilot's hand held batteries were
>> also moribund. I did manage to get clearance to land at Dulles
>> with only the receiver working.
>
> Lithium batteries will hold their charge for a decade at least. They
> are also very light, and they provide high current on demand. I use
> them exclusively for everything when I have the option.
>

Even plain old Alkalines will work. The problem is NiCads and NiMH
suffer from self discharge which is excacerbated by heat (i.e.,
leaving the radio to bake in closed up airplane).

[Peter Clark]

On 25 Sep 2006 19:43:30 -0700, wrote:

>> At first I read this as the master, but I think you meant the avionics
>> master. Did any radio lights come on? Did the transponder do its
>> transponder blikey thing?
>
>It was the avionics master, yes. Everything but the audio panel came
>back on - the radio were just fine, but with a dead audio panel there's
>no way to use them!

The 2000 SPs have dual-bus avionics masters. Just curious, did you
try just one side of the switch? Kill the avionics master, turn
everything off by their individual switches and then try turning back
on just the COM1 etc? Also, without a functioning audio panel (if
that's the component which broke) the EMRG mode (click the on/off
switch) should tie you directly to COM1 and give you a radio.

Course, if you're staring at an airport when it happens and not IMC at
the time, the checklist is pretty pointless beyond "turn off power to
all devices."

[Emily[_1_]]

Roy Smith wrote:
> In article >,
> Jose > wrote:
>
>> If you key the mike, does the TX light up? You could go to 121.5 and
>> use morse code. Clumsy, but possible in a true emergency, so long as
>> you don't get distracted by it.
>
> OK, all you controller types out there -- what are the odds that anybody on
> 121.5 would know enough code these days to have a clue what was being sent
> (or even recognize it as anything but a bunch of annoying clicking noises).

Actually, an easy, although slow way, is to use the identification
symbol on a VOR on a chart for a guide. I've entertained myself on long
flights like that before.

[Jay Beckman]

"Peter Clark" > wrote in message
...
> On 25 Sep 2006 19:43:30 -0700, wrote:
>
>>> At first I read this as the master, but I think you meant the avionics
>>> master. Did any radio lights come on? Did the transponder do its
>>> transponder blikey thing?
>>
>>It was the avionics master, yes. Everything but the audio panel came
>>back on - the radio were just fine, but with a dead audio panel there's
>>no way to use them!
>
> The 2000 SPs have dual-bus avionics masters. Just curious, did you
> try just one side of the switch?

???

THE Master is a two-part red switch (ALT/BAT) but AFAIK, the "Avionics
Master" is a one piece white switch.
Of course, each component has it's own on-off interface.

Jay B

[Peter Clark]

On Tue, 26 Sep 2006 15:31:50 -0700, "Jay Beckman" >
wrote:

>
>"Peter Clark" > wrote in message
...
>> On 25 Sep 2006 19:43:30 -0700, wrote:
>>
>>>> At first I read this as the master, but I think you meant the avionics
>>>> master. Did any radio lights come on? Did the transponder do its
>>>> transponder blikey thing?
>>>
>>>It was the avionics master, yes. Everything but the audio panel came
>>>back on - the radio were just fine, but with a dead audio panel there's
>>>no way to use them!
>>
>> The 2000 SPs have dual-bus avionics masters. Just curious, did you
>> try just one side of the switch?
>
>???
>
>THE Master is a two-part red switch (ALT/BAT) but AFAIK, the "Avionics
>Master" is a one piece white switch.
>Of course, each component has it's own on-off interface.

The new Skyhawks/Skylanes etc (I believe it's back to the restart of
the line) have 2 busses and a split avionics master as well.

[Jay Beckman]

"Peter Clark" > wrote in message
...
> On Tue, 26 Sep 2006 15:31:50 -0700, "Jay Beckman" >
> wrote:
>
>>
>>"Peter Clark" > wrote in message
...
>>> On 25 Sep 2006 19:43:30 -0700, wrote:
>>>
>>>>> At first I read this as the master, but I think you meant the avionics
>>>>> master. Did any radio lights come on? Did the transponder do its
>>>>> transponder blikey thing?
>>>>
>>>>It was the avionics master, yes. Everything but the audio panel came
>>>>back on - the radio were just fine, but with a dead audio panel there's
>>>>no way to use them!
>>>
>>> The 2000 SPs have dual-bus avionics masters. Just curious, did you
>>> try just one side of the switch?
>>
>>???
>>
>>THE Master is a two-part red switch (ALT/BAT) but AFAIK, the "Avionics
>>Master" is a one piece white switch.
>>Of course, each component has it's own on-off interface.
>
> The new Skyhawks/Skylanes etc (I believe it's back to the restart of
> the line) have 2 busses and a split avionics master as well.

My apologies...

You are entirely correct.

Jay B

[NW_Pilot]

> wrote in message
ups.com...
> Well, I haven't posted here in quite awhile. I'm an IFR-rated PP with
> about 400 hours currently. Lately flying about 8 hours a month on
> average.
>
> Had an interesting experience yesterday: a "hard" avionics failure
> complete with something popping/blowing/burning. Flying a very nice,
> new (2000) rented 172SP, there was a pop, the audio panel went dead,
> and then an acrid odor in the cabin.
>
> After the couple seconds of stark surprise I flipped the avionics
> master off. When it appeared there was no real smoke and the smell
> disappated I tried cycling the master. Nothing bad, but no audio panel
> (completely dead) and thus no radios.
>
> I had just traversed a class C area and was still on with approach when
> losing the stack. I also happened to be damned near over an
> uncontrolled field (a generally busy one though approach had called out
> no traffic and none was visible in the pattern 1000' or so below me).
> I decided that I should really land there and pulled the throttle out.
> #1, home field is controlled and I had no radios. #2, since something
> had definitely 'burned' under that panel, I wanted the airplane on the
> ground.
>
> Of course I couldn't get the WX there with no radios. Airport has a
> 4/22 and 14/32. Local winds were generally N-NW. After a slow 180 to
> lose alt I was more or less lined up with 4 and decided that would
> work. However, on short final I noted that I was crabbing a good 30d
> and was high as well, though I could have lost the remaining alt with a
> slip and full flaps easily enough. However, since though I was now
> NORDO it was not an emergency situation, I decided to do a climing 270
> turn into 32, which I did, and was on the ground pretty quickly, all
> the while looking around everywhere for traffic (none).
>
> Taxied to the FBO and grabbed a car back to home airport (45 minute
> drive - was on local sightseeing flight with a coworker and
> girlfriend).
>
> Overall, in retrospect, I was largely happy with my performance as I
> didn't panic or anything of that sort (inexcusable) and got the
> aircraft on the ground pretty quickly. However, I should have done at
> least one thing differently: I should have either left the avionics
> master off or, if leaving it on as I did once determining there was no
> danger, I should have squawked 7600. I never changed my squawk. I
> elected to leave the panel on mainly to give ATC the benefit of my
> return, being right on the border of their airspace, and didn't change
> the squawk because I didn't really think of it. Priority was landing
> and getting out of the airplane.
>
> Oh, I'd also verified the extinguisher on board and had it at the
> ready.
>
> Haven't heard back from the owner yet (local FBO) but I'd imagine a
> resistor or cap in the audio panel itself went. No breaker had popped
> (the audio panel doesn't have its own breaker).
>
> Lessons learned:
>
> 1) ALWAYS have handheld with me. I own one - I'd left it in my own
> 152, which is what I usually fly. Nothing but laziness in not taking
> it with me. (What could go wrong on a short, local flight, after
> all?!)
>
> 2) Take a bit of time to think about a squawk in any lost-comm
> situation. Really, it would have taken 5s to change the squawk and I
> had plenty of time.
>
> Would welcome any comments on the experience.
>

Try, Total G1000 failure (Rebooting PFD every 15 to 20 min) 200 miles over
the Atlantic Ocean In IMC at Night that will keep you on your toes!!!! NO
VHF coverage and limited HF coverage also!!! I Will tell the full story
another day I have been home for a short time and need to rest up was a long
2 weeks! Oh more photo on the way Jay!

[Mxsmanic]

Ron Natalie writes:

> Even plain old Alkalines will work. The problem is NiCads and NiMH
> suffer from self discharge which is excacerbated by heat (i.e.,
> leaving the radio to bake in closed up airplane).

Alkaline batteries slowly self-discharge, too. For the slight
increment in cost of lithium, it seems like a good investment for
things that really might have to work after sitting unused for long
periods. Also, lithium batteries don't leak, ever (at least not in my
experience). The lighter weight always helps, too.

Some lithium batteries can overheat or explode if shorted out, which
is why they are not allowed on aircraft. However, batteries like the
standard lithium AA cells have integrated overcurrent protection that
prevents this from happening. If you're using something that requires
special, fancy cells, it's important to see if they have this type of
protection before bringing them on board. I don't know what kind of
batteries handhelds require.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[[email protected]]

> With most modern audio panels, when they fail, you still have a connection
> to the mic and headset jacks on the #1 COM. You can test this by simply
> turning the audio panel "off" and seeing if the #1 COM works.

There's an emergency switch. It turns out I had forgotten about it
and, yes, I should've been a bit more familiar with all the avionics -
who ever thinks an audio panel has any real complexity?? It doesn't,
but there is a thing or two to know.

If I'd have been in the air for any *significant* time, though, I'm
pretty confident I'd have figured it out.

Switching it "off" does *not* result in COM1 pass-thru. It was off -
dead - the whole time.

[Bill Denton]

"Switching it "off" does *not* result in COM1 pass-thru. It was off -
dead - the whole time."

In most installations, you CAN test the emergency override by turning the
audio panel "off". Intercoms frequently also provide the same capability.

Note that I said "test".

If you have smoke coming out of the audio panel you may well be suffering
component and/or wire damage. Obviously this could affect even "emergency"
operations...





> wrote in message
oups.com...
> > With most modern audio panels, when they fail, you still have a
connection
> > to the mic and headset jacks on the #1 COM. You can test this by simply
> > turning the audio panel "off" and seeing if the #1 COM works.
>
> There's an emergency switch. It turns out I had forgotten about it
> and, yes, I should've been a bit more familiar with all the avionics -
> who ever thinks an audio panel has any real complexity?? It doesn't,
> but there is a thing or two to know.
>
> If I'd have been in the air for any *significant* time, though, I'm
> pretty confident I'd have figured it out.
>
> Switching it "off" does *not* result in COM1 pass-thru. It was off -
> dead - the whole time.
>

[Thomas Borchert]

Ron,

> I wouldn't bother sqawking IFR.
>

Huh? 7600 has NOTHING to do with IFR. It's the lost comm squawk. It
would have helped ATC tremendously to know what was going on with this
guy they were talking to. There was a very real point in setting 7600.
How could it not be?

--
Thomas Borchert (EDDH)

[Thomas Borchert]

> Nothing bad, but no audio panel
> (completely dead) and thus no radios.
>

That's unusual. Normally, the COM1 should work failsafe through it,
unless cables break. You should look into that - might be the wiring.

Also, as you say yourself, that's exactly the situation 7600 is meant
for.

--
Thomas Borchert (EDDH)

[Thomas Borchert]

> who ever thinks an audio panel has any real complexity??

Uhm, I do. Did so from day one.
It doesn't,

> Switching it "off" does *not* result in COM1 pass-thru. It was off -
> dead - the whole time.

Then it is not correctly wired.

--
Thomas Borchert (EDDH)

[Ron Natalie]

Thomas Borchert wrote:
> Ron,
>
>> I wouldn't bother sqawking IFR.
>>
>
> Huh? 7600 has NOTHING to do with IFR. It's the lost comm squawk. It
> would have helped ATC tremendously to know what was going on with this
> guy they were talking to. There was a very real point in setting 7600.
> How could it not be?
>

He was VFR outside of any airspace that required communications and
going to land. Just how would 7600 done a whole lot for this situation?

[Thomas Borchert]

Ron,

> He was VFR outside of any airspace that required communications and
> going to land. Just how would 7600 done a whole lot for this situation?
>

This quote from the OP might help:

"I had just traversed a class C area and was still on with approach when
losing the stack."

--
Thomas Borchert (EDDH)