MAYDAY in the Everglades

Mark Hansen wrote:
On 5/4/2005 08:13, Dave Butler wrote:

Mark Hansen wrote:


I realize there are some cases that you just can't account for, but
it seems like there should have been a route that would not have been
quite so perilous.


You can go through the Miami class B. Good luck getting cleared
through there in a VFR 150. You can go over the top of Miami class B
(long way to climb in a 150, but possible). You can go east of the
class B over the ocean, or you can go west of the class B over the swamp.


Are you suggesting that it is reasonable to fly in such a case simply
because
it's difficult (or impossible) to find a safer route?

No. I suggested no such thing.

Mark Hansen wrote:
On 5/4/2005 08:20, Dave Butler wrote:

Marty from Sunny Florida wrote:

The sky was clear, and when I got my pre-flight briefing, the temp
was 26
and dew point 16. It was unseasonably cool and very dry for Florida. At
altitude, I knew the air had almost no moisture, but on the way up,
we did
have a typical hazy layer.


Temp 26 and dewpoint 16 puts you well outside the icing region on this
chart:

http://www.ez.org/carb_ice.htm


I assumed the temperatures provided by the original poster were in
centigrade. That puts the temp at 79 deg F and the dew point at 61 deg F.

Assuming 2 deg C drop per thousand feet, that puts the temperature
at 57 deg F and the dew point at 35 deg F. Very close to the blue
"Icing at glide and cruise power" band.

You're right. I did the unit conversion correctly on one axis, but somehow
muffed the other axis. Thanks.

Mark Hansen wrote:

I guess everyone will have their own personal safety margins, but if
I was unable to come up with a way to safely make the flight, I would
not fly. Perhaps this is simply due to my lack of experience.

Don't plan on flying to Key West, then.

George Patterson
There's plenty of room for all of God's creatures. Right next to the
mashed potatoes.

I'm extremely impressed with the response I've gotten to this post. I know
as a given fact that I will not get hurt in a general aviation aircraft that
I'm flying during daylight hours. It's just a fact that comes with a great
respect for the unexpected (I have a healthy fear of what I don't know). I'm
a pre-flight nut case. I sump the fuel always, even after a 10 minute stop
without re-fueling. The plane has an almost zero time status (now at 125
hours since major OH). I'd had an oil change a couple of days earlier and
wondered if my mechanic had nicked the fuel line, or in some odd manner made
a change to the fuel system, but that didn't and still doesn't make sense.

Regarding my flight plan- I have been tossed out of Miami's Bravo airspace
about as often as girls turned me down when I was a teenager. Not being shy,
that's a lot. The only choice is over the ocean below 3,000, over MIA's
airspace at 7,000 or the swamp to the west. I take the swamp because it's
quiet (except for a few minutes when the big jets are turning final while
West of MIA). At all times I check to make certain I have enough altitude
(except when climbing out, of course), to make solid ground. This time I
knew I could make the interstate, but would truly choose this as a last
resort. The NTSB would get involved, and I'd have to get the plane trucked
out of the everglades. To save my wife and I, I would do this in a
heartbeat. My preference, of course, would be to put down at an airfield,
which I did.

Someone asked me what I'd do differently, and my wife and I have discussed
this several times since Friday. The answer comes up every time - Nothing. I
did and would still do exactly as before, but probably swap the first thing
= full rich to first thing = carb heat. Other than that, no other change. I
didn't touch the mags for concern I'd kill the engine. A dead mag will rob
you of power, but it won't cause a rough sputter. I've been trained to make
as little change to a failing engine as possible. Even an aiplane that's
lost it's oil will continue to fly a lot longer if you don't touch the
throttle or mixture. It's when you make a change that an opportunity to
seize occurs. I did, however, push and poke everything else (or what litter
there is to push in a C152).

My wife who's not a pilot, but spends a lot of time in the right seat
telling me where to go, concluded carb ice. She did this when we first
touched down at Dade-Collier airport. My mechanic on the phone explained
that a bad cylinder wouldn't fix itself, but water in the tanks would
eventually blow through the system. The mechanic I met on the ramp also said
bad fuel. My buddy and CFI back in Lantana (I called everyone), said bad
gas. My wife insisted carb ice.

So whadayall' say. Should I give my pilots license to Lynda or what?

Marty

Marty from Florida wrote:

I didn't touch the mags for concern I'd kill the engine.

I agree with you completely. Switching to one mag would help only in a situation
in which a mag has jumped time. Your description of the symptoms doesn't match
what happens when a mag's mistimed (backfiring usually comes into the picture in
this case). I would not have touched the ignition switch.

George Patterson
There's plenty of room for all of God's creatures. Right next to the
mashed potatoes.

("tony roberts" wrote)
[snips]
When I read your report I was very suprised to read that all of your
preliminary steps - after discovering the problem, did not even consider
carb ice. I believe that carb ice is exactly what you had.

In my part of the world the procedure for those symptoms is -
Best Glide
Find landing area
Carb Heat
Briefing
Cause check
Radio
Act accordingly


I was surprised that the OP turned around to make an airport he didn't think
he could make - if the rough running engine quit. I mean ....GATORS!!!

(The swamp flight)
Efficiently, he ascertained our position and vectored me to the Dade-Collier
airport, which is in the middle of nowhere. Ironically, so were we! The
strip was 17 miles to our southwest, which is farther than a dead engine
would take me. We had been heading due north to a safe landing point on
I75
when ATC advised us to turn our backs on the hwy and return south. In my
heart, we turned away from solid ground to face only swamp again. I
decided
to trust fate and the ATC controller as I asked the alligators to gift me
the extra minutes of engine power needed to make the airport.


I guess I was overly fixated (on the very real possibility) of the OP being
grabbed, rolled, then stuffed under a submerged log by a giant 30 ft long
alligator. Chomp, chomp, chomp. Right about then, having your plane run over
by a Peterbilt must sound like a pretty good plan B!!

Anyway that was my armchair thought (reaction) when I first read the report.
Am interested to learn what it was that caused the engine(s) to act up?


Montblack

Montblack wrote:

I mean
....GATORS!!!

Gators aren't the real problem there (unless you get too close to a female on
her nest). They rarely attack anything big. You're much more likely to tangle
with a poisonous snake. Even if you avoid these, the skeeters will drain you dry
in no time.

George Patterson
There's plenty of room for all of God's creatures. Right next to the
mashed potatoes.

Did you try aggressively leaning while having full carb heat? Possibly
your engine was flooding out from an iced carb venturi. You mentioned
going to full rich, but if it is an icing situation, it may instead
require further leaning with carb heat on and full throttle to get
enough heat in the exhaust system to melt the intake ice. It won't
necessarily melt out right away either, and I assume you had carb heat
on for enough time to clear out any ice It might take say 15 seconds
minimum. When the ice melts, the engine will go rough again until you
set things richer.

Another remote possibility is a valve sticking open. Usually that
happens on startup, and I have never experienced it. That engine has
some history of having sticking problems. You were not that far from
the last major and I assume the oil was reasonably clean so that might
rule that possibility out. Q - was it one cylinder missing (i. e. a
stuck valve) or was it a general engine malaise (mixture problems)?

Mixture and ice problems are why I really like having an EGT to cross
check the combustion and the energy extraction process.

Actually a 4 cyl engine running on three cylinders for whatever reason
will only generate about 50% power and will feel very rough. However,
it can still extend your glide a long long way.

Congrats on making it down OK. The first engine failure is the worst.
Next time won't seem so bad.........!

"Marty from Florida" marty@-x-x-x- remove -x-x- worth.net writes:

[...] I know as a given fact that I will not get hurt in a general
aviation aircraft that I'm flying during daylight hours. It's just a
fact that comes with a great respect for the unexpected (I have a
healthy fear of what I don't know). [..]

I hate to say this, but all that respect and pre-flight attention is
just not a guarantee that you won't be hurt. There are unfortunately
many ways to get hurt in an airplane, some foreseeable, some
preventable, and some neither. I don't want to scare you by dreaming
up scenario after scenario, but rest assured that they exist.

- FChE

George Patterson wrote:
: Mark Hansen wrote:
:
: I guess everyone will have their own personal safety margins, but if
: I was unable to come up with a way to safely make the flight, I would
: not fly. Perhaps this is simply due to my lack of experience.

: Don't plan on flying to Key West, then.

Or Martha's Vineyard, Nantuckett, or Block Island. All 10nm offshore.
--
Aaron C.