Avionics failure yesterday...

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.

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

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.

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.

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.

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.
|

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.

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.

Jose wrote:
snip

"little queasy" was not a medical emergency.

Never had a pax throw up on you, huh?

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.