MAYDAY in the Everglades

[Marty from Sunny Florida]

Hello everyone.



The end of my story is this; We landed safely in the middle of the Florida
Everglades and didn't get a single Alligator bite. Here's what happened;



On Friday, April 29th, we took our Cessna 152 from Lantana, Florida to the
center of the State for gas and start our trek south to Key West. The total
journey is a little over 2 hours.



Forty five minutes after filling with gas in Pahokee, we were just below
Alligator Alley (highway 75). Our engine hiccupped. A few minutes later, it
hiccupped again, this time losing a couple of hundred RPM. We were at 6,800
feet, strait and level flight running at 75% power (about 2350 RPM). The
mixture had been leaned back about 30 minutes earlier, and none of the
engine instruments had changed from the time we made our cruise altitude.



As the hiccups got closer together engine power dropped off significantly,
grabbing our total attention. My first move was pulling up on the yoke to
maintain altitude. I trimmed to our plane's best glide of 60 kts When the
sputtering became a constant rough drone, the engine still held some power,
and we could see nothing but marsh. I though about the choice between
ditching in green or brown muck, not sure where the biggest alligators live.
There was absolutely no solid ground as far as the eye could see. Solemnly,
I rolled the 'standby' frequency to 121.5 acknowledging the severity of our
predicament.

Acting on the premise that the engine could quit at any moment and our best
option was behind us on highway I75, I started a very gentle 180 degree
turn.



Oil pressure was in the green. Oil temp was in the green. Mags were on BOTH.
The fuel showed close to full (I had at least 18 gallons useable). My only
immediate change was to push the mixture to full rich, which had no effect.
When I touched the throttle to add power, the RPM dropped. Gently, I
returned the throttle and the power evened out.



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. My next move was carb heat, even though there was
absolutely no visible moisture. It did smooth out the roughness slightly,
but did nothing for the power loss.



The engine was dying, and the math was simple. Sink at 500 fpt, 6,800 feet
gives me about 13 minutes and at 60 kts, I'd get about 15 statute miles. I
knew I could make the highway without an engine.



I've personally had experience looking for downed aircraft in the Florida
swamp, and know how difficult it is to spot a small plane. We needed to let
someone know our position and situation. We had the skill to find the
closest airport but every moment was precious. ATC could save valuable
minutes and that might make the difference. With this in mind, I hit the
radio's flip-flop button and announced our tail number on the emergency
frequency.



The Controller was a true professional. He asked me a few questions and
instructed me to "ident" before assigning a squawk code. The radio reception
was not clear, which generated a stream of "say agains". This, of course
added to the general stress of the situation.



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.



Trimmed back to slow flight, we managed to barely maintain altitude. We
arrived at the 10,500 foot runway with 3,200 feet of altitude and 120 kts of
air speed. I figure I could have made 4 complete turns around the pattern
and still land hot. I have never been so relieved in my entire life.



On the ground, we taxied to an area near two other planes. Relieved and
curious I did a runup and the engine gave a text book performance.



Our cell phones didn't work so we called the FBO on the radio. We were
invited into the small building nearby where there was a phone. There we
learned that the other two planes had landed the day before with similar
symptoms.



I phoned my mechanic and relayed the story. He gave me some great advice and
a definite suggestion about what caused the problem. We returned to the
plane to follow my mechanics instructions.



Another mechanic, who had come to pick up one of the other downed planes
kindly offered to look at my engine. He pulled the cowl open, checked the
cables on the throttle, carb heat and mixture. He sat in the 152 with me
while I did a regular and then full-power run up. The engine showed great
response to throttle, the mixture choked it and the carb heat performed as
advertised.



This qualified mechanic was planning to fly out in a plane that landed in
the same condition as ours. They offered us a ride if we were not
comfortable flying our 152. We had options. Now, we had to make a decision
to take the ride or hop in our plane and head out.



The logic was: someone at some point would fly our 152 out, and we would
again need to fly this same plane at some point ourselves. If we waited,
what would be different? A qualified mechanic not only said it was safe, but
was flying out a plane in the same condition. We decided the problem had
resolved itself. We would fly.



After a lengthy check, we headed for the runway. I did a steep climb over
the field, continued uphill after completing a long, slow circuit of the
airport, and headed north with a 500 FPM climb. All the while, I knew I
could glide back to the runway if needed.



It was late to start our day in the Keys so we turned towards home. When We
sighted I75, I knew I was home free. If there was trouble we were guaranteed
a level spot to land. We made Lantana at full power with no sign of the
earlier problem.



I must say, I am impressed with the FAA system and the people who dedicate
their careers to the safety of our skies. This system that trains and relies
on the good judgment of the individual pilot also supports the decisions
necessary in crisis. While part of the mandate of the FAA is to enforce the
laws, a pilot's decisions are respected even when they are examined. I find
great comfort in the FAA and the service it provides to general aviation.



If our highways resembled our skies, perhaps the average driver would be
less likely to knowingly break the law.



Here's my question to this group. What caused the engine failure? More than
one thought is welcome, but please explain your answer. I have one of two
possibilities in my head, and invite any questions, advise, opinions, or
wisdom.



Warm regards from one very happy pilot.



Marty

[Robert M. Gary]

Carb ice. Of course, I wasn't sitting there with you so its just an arm
chair opinion. You say the carb heat worked as advertised but did you
turn it on?

Fuel venting. I'm trying to remember how a 152's fuel is vented. Is it
vented caps or a venting tube? It could have gotten a bit plugged by
dead bugs moving around. If you havent' already, I would remove the
caps and blow air into the tank to see if there is any restrictions.

Great job of handling an uneasy situation with professionalism.

-Robert, CFI

[BTIZ]

I'll agree to the carb ice... and sometimes.. if heat applied to late.. it
does not work..

one can expect the engine to run rougher after initial application of carb
heat.. while the engine swallows the ice and water... then a marked
improvement... sometimes people get the rougher engine and immediately turn
the carb heat lever back to off and not give it a chance..

BT

"Robert M. Gary" > wrote in message
ups.com...
> Carb ice. Of course, I wasn't sitting there with you so its just an arm
> chair opinion. You say the carb heat worked as advertised but did you
> turn it on?
>
> Fuel venting. I'm trying to remember how a 152's fuel is vented. Is it
> vented caps or a venting tube? It could have gotten a bit plugged by
> dead bugs moving around. If you havent' already, I would remove the
> caps and blow air into the tank to see if there is any restrictions.
>
> Great job of handling an uneasy situation with professionalism.
>
> -Robert, CFI
>

[Marty from Florida]

Thanks so far for the responses. To elaborate;

The late model C152 (mine's a 1982), has a fuel vent for the left wing and a
vent cap for the right side. I can blow bubbles up the vent tube, and in
fact a primary consideration during my event was wing vaccuum. My head went
to the wings, but I realized fuel starvation was more likely from a clogged
fuel filter, or pinched line. There's no pump, just gravity.

Regarding carb ice -
Immediately after pushing the mixture to full rich without result, I added
carb heat. It did very little, but I left it in, which is almost against my
religion as it simply fouls plugs in the Florida climate, and little else.
My thoughts on this one are simple; I'm at altitude on a brisk clear day,
with NO VISIBLE MOISTURE. There was some cloud cover above (I estimate
10,000 + altitude). The effect of carb icing is simple - a gradual decrease
in power with engine roughness, which is exactly what I experienced. The
problem was, I had no further power reduction when I added carb heat, which
typically occurs as the ice turns to water and temporarily fouls ignition. I
should have seen an increase in power as the water blew through the carb.
Also, why did adding throttle cause an RPM drop? Is this consistent with
carb iceing?

Also keep in mind that my flight was stable for about 30 minutes when the
hiccup started. I hadn't flown through a cloud and there was no turbulance.

I'll wait for some further input before adding my conclusion and the
subsequent decision to take the plane back into the sky.

Marty

[Vaughn]

Marty
> Forty five minutes after filling with gas in Pahokee, we were just below
> Alligator Alley (highway 75). Our engine hiccupped. A few minutes later, it
> hiccupped again, this time losing a couple of hundred RPM. We were at 6,800
> feet, strait and level flight running at 75% power (about 2350 RPM). The
> mixture had been leaned back about 30 minutes earlier, and none of the
> engine instruments had changed from the time we made our cruise altitude.
>
> As the hiccups got closer together engine power dropped off significantly,
> grabbing our total attention. My first move was pulling up on the yoke to
> maintain altitude. I trimmed to our plane's best glide of 60 kts

Good! Exactly correct for step one on the "Power Loss in Flight"
checklist.

>When the
> sputtering became a constant rough drone, the engine still held some power,
> and we could see nothing but marsh. I though about the choice between
> ditching in green or brown muck, not sure where the biggest alligators live.
> There was absolutely no solid ground as far as the eye could see. Solemnly,
> I rolled the 'standby' frequency to 121.5 acknowledging the severity of our
> predicament.
>
> Acting on the premise that the engine could quit at any moment and our best
> option was behind us on highway I75, I started a very gentle 180 degree
> turn.
>
> Oil pressure was in the green. Oil temp was in the green. Mags were on BOTH.
> The fuel showed close to full (I had at least 18 gallons useable). My only
> immediate change was to push the mixture to full rich, which had no effect.
> When I touched the throttle to add power, the RPM dropped. Gently, I
> returned the throttle and the power evened out.

> 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. My next move was carb heat,

You got this far before you tried step two!

>even though there was absolutely no visible moisture.

The "power loss in Flight" checklist for the 152 says nothing about visible
moisture...just do what it says! You took way too long to try carb heat. From
what I understand, there are two reasons for using carb heat in the 152: 1) the
obvious one and, 2) It bypasses the air filter giving you an alternate air
supply for the engine.

Other than that, you did a good job. I also fly out of Lantana and may fly
that same plane.


See you there,
Vaughn

[houstondan]

i can't imagine you would drop in the stuff about 2 other planes
arriving with similar symptoms if the mechanic there to ferry one back
out didn't have a theory that gave both of you enough confidence to
fly.

with those temperatures, izzit possible that you're dealing with ice in
the tanks?

dan

[Ron McKinnon]

"Marty from Sunny Florida" > wrote in message
...
> ... We were at 6,800 feet, strait (sic) and level flight running
> at 75% power (about 2350 RPM) ...

Peculiar cruising altitude, BTW (the glades aren't above
3800 feet, are they?) ...

> 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,

With temp 26, dew point 16, there's definitely moisture
there. Cool that air down to 16, and you'll start to get
condensation.) At 6800 feet the OAT would have been
cooler and the spread less.

> ... My next move was carb heat, even though there was
> absolutely no visible moisture.

NB: There is absolutely *no* requirement for 'visible
moisture' for carb ice to occur.

> It did smooth out the roughness slightly, but did nothing
> for the power loss. ...

As others have observed, this is entirely consistent with
carb icing, and (if you didn't (you didn't actually say)) you
should have left the carb heat on.

The unusual cold (for Florida) and the couple of planes
that had the same problem the day before would suggest
this as well. It's lookin' like Florida doesn't get enough
experience with carb icing. (I'm not criticising, just
jealous.))

But good job!, and good story.

[Frank Ch. Eigler]

"Marty from Sunny Florida" > writes:

> [...]
> 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. [...]

If these are in degrees Celsius, then there is ample moisture in the air.

> My next move was carb heat, even though there was absolutely no
> visible moisture. [...]

You misunderstand the nature of carb icing. Visible moisture (rain?
cloud? thick mist?) is not a prerequisite.


- FChE

[George Patterson]

Marty from Sunny Florida wrote:
>
> Here's my question to this group. What caused the engine failure?

Carb ice. The only two things that I can think of that can cause those symptoms
in several aircraft at the same time are ice and fuel contamination. Fuel
contamination doesn't go away after you land, therefore it was carb ice. The
reason carb heat didn't melt the ice is that you didn't use it soon enough. By
the time you got the heat on, the engine had been running at low power long
enough to cool off.

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

[Jim Burns]

Carb ice. As the others have said if it's applied too late carb heat may
not have any effect once the ice has accumulated in the venturi. Visible
moisture is not necessary for carb ice, you only need adequate humidity and
according to Lycoming temps between 20 and 90 degrees F. Continental
engines can form carb ice at even higher temps due to the position of the
carburetor and remember that warmer air can hold more moisture than cold air
so when carb ice develops at high temperatures it can be more severe. A
full rich mixture can create carb ice even easier because now the carburetor
is vaporizing more fuel creating a greater temperature drop. Adding
throttle (fuel) can also cause an increase in carb ice due to the additional
drop in temperature caused by the additional vaporizing fuel. After you
landed and taxied around at relatively low RPMS (low amount of fuel
vaporizing, warmer carb temps) the problem disappeared. Beware of it
re-occurring on take off when you pour huge amounts of fuel through that
carburetor again at full rich mixture.

The non-textbook experience you presumably had with carb ice could be
attributed to the engine ingesting chunks of ice departing first the
throttle plate, then later off the venturi itself.

The fact that several other airplanes in the area had the same problems also
leads me to lean towards carb ice.

This is the second post in as many months that has indicated that carb ice
requires visible moisture. Structural ice requires visible moisture. Carb
ice can form in visible moisture but it is not at all necessary. Either
there are a lot of instructors mis-informing students on this matter or the
FAA needs to get out a new AC on carb ice. Maybe both.

Marty you did a great job holding your composure, thinking things through,
and making good decisions. I'm glad you made it to the airport.

Jim

[tony roberts]

Hi Marty

I read your post earlier today at work but was too busy to respond.
Now I have time.
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

HTH

Tony


In article >,
"Marty from Sunny Florida" > wrote:

> Hello everyone.
>
>
>
> The end of my story is this; We landed safely in the middle of the Florida
> Everglades and didn't get a single Alligator bite. Here's what happened;
>
>
>
> On Friday, April 29th, we took our Cessna 152 from Lantana, Florida to the
> center of the State for gas and start our trek south to Key West. The total
> journey is a little over 2 hours.
>
>
>
> Forty five minutes after filling with gas in Pahokee, we were just below
> Alligator Alley (highway 75). Our engine hiccupped. A few minutes later, it
> hiccupped again, this time losing a couple of hundred RPM. We were at 6,800
> feet, strait and level flight running at 75% power (about 2350 RPM). The
> mixture had been leaned back about 30 minutes earlier, and none of the
> engine instruments had changed from the time we made our cruise altitude.
>
>
>
> As the hiccups got closer together engine power dropped off significantly,
> grabbing our total attention. My first move was pulling up on the yoke to
> maintain altitude. I trimmed to our plane's best glide of 60 kts When the
> sputtering became a constant rough drone, the engine still held some power,
> and we could see nothing but marsh. I though about the choice between
> ditching in green or brown muck, not sure where the biggest alligators live.
> There was absolutely no solid ground as far as the eye could see. Solemnly,
> I rolled the 'standby' frequency to 121.5 acknowledging the severity of our
> predicament.
>
> Acting on the premise that the engine could quit at any moment and our best
> option was behind us on highway I75, I started a very gentle 180 degree
> turn.
>
>
>
> Oil pressure was in the green. Oil temp was in the green. Mags were on BOTH.
> The fuel showed close to full (I had at least 18 gallons useable). My only
> immediate change was to push the mixture to full rich, which had no effect.
> When I touched the throttle to add power, the RPM dropped. Gently, I
> returned the throttle and the power evened out.
>
>
>
> 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. My next move was carb heat, even though there was
> absolutely no visible moisture. It did smooth out the roughness slightly,
> but did nothing for the power loss.
>
>
>
> The engine was dying, and the math was simple. Sink at 500 fpt, 6,800 feet
> gives me about 13 minutes and at 60 kts, I'd get about 15 statute miles. I
> knew I could make the highway without an engine.
>
>
>
> I've personally had experience looking for downed aircraft in the Florida
> swamp, and know how difficult it is to spot a small plane. We needed to let
> someone know our position and situation. We had the skill to find the
> closest airport but every moment was precious. ATC could save valuable
> minutes and that might make the difference. With this in mind, I hit the
> radio's flip-flop button and announced our tail number on the emergency
> frequency.
>
>
>
> The Controller was a true professional. He asked me a few questions and
> instructed me to "ident" before assigning a squawk code. The radio reception
> was not clear, which generated a stream of "say agains". This, of course
> added to the general stress of the situation.
>
>
>
> 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.
>
>
>
> Trimmed back to slow flight, we managed to barely maintain altitude. We
> arrived at the 10,500 foot runway with 3,200 feet of altitude and 120 kts of
> air speed. I figure I could have made 4 complete turns around the pattern
> and still land hot. I have never been so relieved in my entire life.
>
>
>
> On the ground, we taxied to an area near two other planes. Relieved and
> curious I did a runup and the engine gave a text book performance.
>
>
>
> Our cell phones didn't work so we called the FBO on the radio. We were
> invited into the small building nearby where there was a phone. There we
> learned that the other two planes had landed the day before with similar
> symptoms.
>
>
>
> I phoned my mechanic and relayed the story. He gave me some great advice and
> a definite suggestion about what caused the problem. We returned to the
> plane to follow my mechanics instructions.
>
>
>
> Another mechanic, who had come to pick up one of the other downed planes
> kindly offered to look at my engine. He pulled the cowl open, checked the
> cables on the throttle, carb heat and mixture. He sat in the 152 with me
> while I did a regular and then full-power run up. The engine showed great
> response to throttle, the mixture choked it and the carb heat performed as
> advertised.
>
>
>
> This qualified mechanic was planning to fly out in a plane that landed in
> the same condition as ours. They offered us a ride if we were not
> comfortable flying our 152. We had options. Now, we had to make a decision
> to take the ride or hop in our plane and head out.
>
>
>
> The logic was: someone at some point would fly our 152 out, and we would
> again need to fly this same plane at some point ourselves. If we waited,
> what would be different? A qualified mechanic not only said it was safe, but
> was flying out a plane in the same condition. We decided the problem had
> resolved itself. We would fly.
>
>
>
> After a lengthy check, we headed for the runway. I did a steep climb over
> the field, continued uphill after completing a long, slow circuit of the
> airport, and headed north with a 500 FPM climb. All the while, I knew I
> could glide back to the runway if needed.
>
>
>
> It was late to start our day in the Keys so we turned towards home. When We
> sighted I75, I knew I was home free. If there was trouble we were guaranteed
> a level spot to land. We made Lantana at full power with no sign of the
> earlier problem.
>
>
>
> I must say, I am impressed with the FAA system and the people who dedicate
> their careers to the safety of our skies. This system that trains and relies
> on the good judgment of the individual pilot also supports the decisions
> necessary in crisis. While part of the mandate of the FAA is to enforce the
> laws, a pilot's decisions are respected even when they are examined. I find
> great comfort in the FAA and the service it provides to general aviation.
>
>
>
> If our highways resembled our skies, perhaps the average driver would be
> less likely to knowingly break the law.
>
>
>
> Here's my question to this group. What caused the engine failure? More than
> one thought is welcome, but please explain your answer. I have one of two
> possibilities in my head, and invite any questions, advise, opinions, or
> wisdom.
>
>
>
> Warm regards from one very happy pilot.
>
>
>
> Marty




--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE

[Scott D.]

On Wed, 04 May 2005 06:01:22 GMT, tony roberts >
wrote:

>Hi Marty
>
>I read your post earlier today at work but was too busy to respond.
>Now I have time.
>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
>
>HTH
>
>Tony
>
I think that everyone here is pretty much in agreement that carb ice
is suspect numero uno here. But there is something that I teach my
students to do is immediately pull the carb heat (and leave it on)
while you are setting up for best glide and looking for a suitable
landing site. It takes a tenth of a second to reach and pull that
knob. The longer you wait to do this, the cooler the engine is
getting and carb heat becomes less effective. Then after you have
obtained best glide and you are heading for your landing site, then go
through the troubleshooting and preparing for an emergency landing.

Scott D

To email remove spamcatcher's

[Maule Driver]

Yep, that was exactly my thinking. If the a/c were all from the same
field or stopped the same place for fuel, contamination would be a
suspect... otherwise carb ice. Great lesson for those that have never
experienced it.

George Patterson wrote:
> Carb ice. The only two things that I can think of that can cause those
> symptoms in several aircraft at the same time are ice and fuel
> contamination. Fuel contamination doesn't go away after you land,

[TripFarmer]

Did you check the fuel after you fueled at Pahokee?


Trip

In article >, says...
>
>Hello everyone.
>
>
>
>The end of my story is this; We landed safely in the middle of the Florida
>Everglades and didn't get a single Alligator bite. Here's what happened;
>
>
>
>On Friday, April 29th, we took our Cessna 152 from Lantana, Florida to the
>center of the State for gas and start our trek south to Key West. The total
>journey is a little over 2 hours.
>
>
>
>Forty five minutes after filling with gas in Pahokee, we were just below
>Alligator Alley (highway 75). Our engine hiccupped. A few minutes later, it
>hiccupped again, this time losing a couple of hundred RPM. We were at 6,800
>feet, strait and level flight running at 75% power (about 2350 RPM). The
>mixture had been leaned back about 30 minutes earlier, and none of the
>engine instruments had changed from the time we made our cruise altitude.
>
>
>
>As the hiccups got closer together engine power dropped off significantly,
>grabbing our total attention. My first move was pulling up on the yoke to
>maintain altitude. I trimmed to our plane's best glide of 60 kts When the
>sputtering became a constant rough drone, the engine still held some power,
>and we could see nothing but marsh. I though about the choice between
>ditching in green or brown muck, not sure where the biggest alligators live.
>There was absolutely no solid ground as far as the eye could see. Solemnly,
>I rolled the 'standby' frequency to 121.5 acknowledging the severity of our
>predicament.
>
>Acting on the premise that the engine could quit at any moment and our best
>option was behind us on highway I75, I started a very gentle 180 degree
>turn.
>
>
>
>Oil pressure was in the green. Oil temp was in the green. Mags were on BOTH.
>The fuel showed close to full (I had at least 18 gallons useable). My only
>immediate change was to push the mixture to full rich, which had no effect.
>When I touched the throttle to add power, the RPM dropped. Gently, I
>returned the throttle and the power evened out.
>
>
>
>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. My next move was carb heat, even though there was
>absolutely no visible moisture. It did smooth out the roughness slightly,
>but did nothing for the power loss.
>
>
>
>The engine was dying, and the math was simple. Sink at 500 fpt, 6,800 feet
>gives me about 13 minutes and at 60 kts, I'd get about 15 statute miles. I
>knew I could make the highway without an engine.
>
>
>
>I've personally had experience looking for downed aircraft in the Florida
>swamp, and know how difficult it is to spot a small plane. We needed to let
>someone know our position and situation. We had the skill to find the
>closest airport but every moment was precious. ATC could save valuable
>minutes and that might make the difference. With this in mind, I hit the
>radio's flip-flop button and announced our tail number on the emergency
>frequency.
>
>
>
>The Controller was a true professional. He asked me a few questions and
>instructed me to "ident" before assigning a squawk code. The radio reception
>was not clear, which generated a stream of "say agains". This, of course
>added to the general stress of the situation.
>
>
>
>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.
>
>
>
>Trimmed back to slow flight, we managed to barely maintain altitude. We
>arrived at the 10,500 foot runway with 3,200 feet of altitude and 120 kts of
>air speed. I figure I could have made 4 complete turns around the pattern
>and still land hot. I have never been so relieved in my entire life.
>
>
>
>On the ground, we taxied to an area near two other planes. Relieved and
>curious I did a runup and the engine gave a text book performance.
>
>
>
>Our cell phones didn't work so we called the FBO on the radio. We were
>invited into the small building nearby where there was a phone. There we
>learned that the other two planes had landed the day before with similar
>symptoms.
>
>
>
>I phoned my mechanic and relayed the story. He gave me some great advice and
>a definite suggestion about what caused the problem. We returned to the
>plane to follow my mechanics instructions.
>
>
>
>Another mechanic, who had come to pick up one of the other downed planes
>kindly offered to look at my engine. He pulled the cowl open, checked the
>cables on the throttle, carb heat and mixture. He sat in the 152 with me
>while I did a regular and then full-power run up. The engine showed great
>response to throttle, the mixture choked it and the carb heat performed as
>advertised.
>
>
>
>This qualified mechanic was planning to fly out in a plane that landed in
>the same condition as ours. They offered us a ride if we were not
>comfortable flying our 152. We had options. Now, we had to make a decision
>to take the ride or hop in our plane and head out.
>
>
>
>The logic was: someone at some point would fly our 152 out, and we would
>again need to fly this same plane at some point ourselves. If we waited,
>what would be different? A qualified mechanic not only said it was safe, but
>was flying out a plane in the same condition. We decided the problem had
>resolved itself. We would fly.
>
>
>
>After a lengthy check, we headed for the runway. I did a steep climb over
>the field, continued uphill after completing a long, slow circuit of the
>airport, and headed north with a 500 FPM climb. All the while, I knew I
>could glide back to the runway if needed.
>
>
>
>It was late to start our day in the Keys so we turned towards home. When We
>sighted I75, I knew I was home free. If there was trouble we were guaranteed
>a level spot to land. We made Lantana at full power with no sign of the
>earlier problem.
>
>
>
>I must say, I am impressed with the FAA system and the people who dedicate
>their careers to the safety of our skies. This system that trains and relies
>on the good judgment of the individual pilot also supports the decisions
>necessary in crisis. While part of the mandate of the FAA is to enforce the
>laws, a pilot's decisions are respected even when they are examined. I find
>great comfort in the FAA and the service it provides to general aviation.
>
>
>
>If our highways resembled our skies, perhaps the average driver would be
>less likely to knowingly break the law.
>
>
>
>Here's my question to this group. What caused the engine failure? More than
>one thought is welcome, but please explain your answer. I have one of two
>possibilities in my head, and invite any questions, advise, opinions, or
>wisdom.
>
>
>
>Warm regards from one very happy pilot.
>
>
>
>Marty
>
>
>
>

[Mark Hansen]

On 5/3/2005 14:58, Marty from Sunny Florida wrote:

> Hello everyone.
>
>

[ snip ]

>
>
> As the hiccups got closer together engine power dropped off significantly,
> grabbing our total attention. My first move was pulling up on the yoke to
> maintain altitude. I trimmed to our plane's best glide of 60 kts When the
> sputtering became a constant rough drone, the engine still held some power,
> and we could see nothing but marsh. I though about the choice between
> ditching in green or brown muck, not sure where the biggest alligators live.
> There was absolutely no solid ground as far as the eye could see. Solemnly,
> I rolled the 'standby' frequency to 121.5 acknowledging the severity of our
> predicament.


First of all, I'm very happy that you were able to land safely. Since
everyone else has dealt with the carb ice issue, I would like to ask
about your position over the glades. Granted I don't have a lot of
experience yet, but I've been taught (sternly) not to allow the
airplane to get anywhere that it can't make a safe landing in the
event of a power failure.

From your description, it sounds like a total power failure would have
left you with a marsh ditching and alligators.

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.

It is not my intention to lecture (nor have I any desire to do so), but
am wondering if this experience will change your mind about the routes
you take in future flights.

Whether or not carb ice was the issue, you still kept your cool
and went through a very straight-forward thought process to determine
the cause of the problem and maintain the safety of your flight. Very
nice job and story!

--
Mark Hansen, PP-ASEL, Instrument Student
Sacramento, CA

[Dave Butler]

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.

[Dave Butler]

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

The temperature at altitude was probably well below 26, but even so you seem to
be pretty well outside the temperature / dewpoint danger zone.

Nevertheless, I agree with the consensus that carb ice is the best explanation.

I'm mystified that the chart doesn't confirm.

Dave

[Mark Hansen]

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.

>
> The temperature at altitude was probably well below 26, but even so you seem to
> be pretty well outside the temperature / dewpoint danger zone.
>
> Nevertheless, I agree with the consensus that carb ice is the best explanation.
>
> I'm mystified that the chart doesn't confirm.
>
> Dave


--
Mark Hansen, PP-ASEL, Instrument Student
Sacramento, CA

[Mark Hansen]

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?

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.

--
Mark Hansen, PP-ASEL, Instrument Student
Sacramento, CA

[Robert M. Gary]

I"m not sure I agree with you regarding carb ice. While it may not have
been your problem, I've had carb ice in the J-3 that resulted in more
than just a drop in RPM, the engine was doing next to nothing. Each
time I've gotten carb ice it has been with not visible moisture. I
think the visible moisture thing is just an old wive's tale. There is
no need for visible moisture to get carb ice.

Does the C-152 have a fuel filter? In my Mooney I have a couple screens
but no "filter" per say. I guess the difference is that the screens (in
theory) are for larger stuff and not as likely to clog.

[Dave Butler]

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.

[Dave Butler]

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.

[George Patterson]

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.

[Marty from Florida]

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

[George Patterson]

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.

[Montblack]

("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

[George Patterson]

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.

[nrp]

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.........!

[Frank Ch. Eigler]

"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

[Aaron Coolidge]

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.

[[email protected]]

Frank Ch. Eigler wrote:
> "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.
>

I've definitely gotta agree with that one. If you know it is a fact
that you won't be hurt in an aircraft that you're flying day VFR, then,
with all due respect, you are deluding yourself. Of course, you
probably won't be convinced of that until it actually happens (been
there, done that, still have the blood soaked T-shirt). A great
respect for the unexpected will not guarantee that the unexpected will
not happen. Not by a long shot.

John Galban=====>N4BQ (PA28-180)

[[email protected]]

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.

I'm not sure what that means. Every flight is an exercise in risk
assesment. Since there are no guarantees that you will ever come up
with a way to "safely make a flight", you'd have to stay on the ground.

The trick is to slant the odds in your favor as much as possible.
Individuals vary in their risk tolerance, so that is a personal
decision. Some people will not fly over any terrain that would not
permit an emergency landing at any time. That's fine for them, but
would seriously limit the utility of an aircraft for most pilots, if
adhered to religiously. In real life, we make trade-offs. A certain
amount of risk, for a certain amount of reward. Where those two
balance are an exercise for the individual.

I rountinely fly my single engine plane in the bottoms of deep
canyons in very mountainous terrain. I know that there are a lot of
places where an engine failure will have a good chance of killing me.
I do everything I can to make sure that I've minimized the risk as much
as possible, but the bottom line is that I'm trading a little safety in
order to enjoy the unique pleasure of flying the backcountry. Lest
you think I'm some kind of daredevil, there are several hundreds of
other pilots that have made similar choices. I'll be the first one to
say that, although I enjoy it immensly, it's not for everybody.

John Galban=====>N4BQ (PA28-180)

[Dave Anderer]

On Wed, 04 May 2005 12:13:10 -0500, Montblack wrote:

> 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!!!

Have to admit that was my impression too. He had a plan that would work,
and traded it (at ATC's suggestion) for one he hoped would work - if all
went well, and the engine didn't get any worse.

Don't know that I would have done the same thing.

[[email protected]]

George Patterson wrote:
> 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.
>
I've had instances of mag failure where switching to one improved the
situation quite a bit. One was a bad timing gear that did include the
backfiring, but another was a shorting distributer block that made the
engine extremely rough and caused a power loss. In that case, I
switched to the good mag and had a much less worriesome ride home.

I guess I don't completely understand your (or Marty's) reluctance to
at least check the mags in flight. Even at best glide, the engine is
not going to come to a stop because you grounded a mag. If it gets
worse, you just switch back, then try the other one. At some point,
you decide which combo (left, right, or both) works best and you leave
it there.

Maybe there is something I haven't considered. If so, I would
welcome enlightenment.

John Galban=====>N4BQ (PA28-180)

[George Patterson]

wrote:
>
> I guess I don't completely understand your (or Marty's) reluctance to
> at least check the mags in flight.

On a Lycoming, each mag controls half the plugs on the top and half on the
bottom. There are a variety of problems that will lead to fouling of the lower
plugs. If I start switching mags on an iced up engine, there's a good chance it
will die. There's also a pretty good chance that it won't restart when I switch
back to both. Especially on a carburetted engine, you run a big risk of flooding
the engine while it's windmilling. As long as the engine's running, I won't take
a chance on switching mags. It's just something I'm not prepared to do.

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

[Toks Desalu]

You should show this story in RAS. I think it is a good story for student
pilots to hear.

Toks Desalu
PP-ASEL
"Dyin' to soar"

"Marty from Sunny Florida" > wrote in message
...
> Hello everyone.
>
>
>
> The end of my story is this; We landed safely in the middle of the Florida
> Everglades and didn't get a single Alligator bite. Here's what happened;
>
>
>
> On Friday, April 29th, we took our Cessna 152 from Lantana, Florida to the
> center of the State for gas and start our trek south to Key West. The
total
> journey is a little over 2 hours.
>
>
>
> Forty five minutes after filling with gas in Pahokee, we were just below
> Alligator Alley (highway 75). Our engine hiccupped. A few minutes later,
it
> hiccupped again, this time losing a couple of hundred RPM. We were at
6,800
> feet, strait and level flight running at 75% power (about 2350 RPM). The
> mixture had been leaned back about 30 minutes earlier, and none of the
> engine instruments had changed from the time we made our cruise altitude.
>
>
>
> As the hiccups got closer together engine power dropped off significantly,
> grabbing our total attention. My first move was pulling up on the yoke to
> maintain altitude. I trimmed to our plane's best glide of 60 kts When the
> sputtering became a constant rough drone, the engine still held some
power,
> and we could see nothing but marsh. I though about the choice between
> ditching in green or brown muck, not sure where the biggest alligators
live.
> There was absolutely no solid ground as far as the eye could see.
Solemnly,
> I rolled the 'standby' frequency to 121.5 acknowledging the severity of
our
> predicament.
>
> Acting on the premise that the engine could quit at any moment and our
best
> option was behind us on highway I75, I started a very gentle 180 degree
> turn.
>
>
>
> Oil pressure was in the green. Oil temp was in the green. Mags were on
BOTH.
> The fuel showed close to full (I had at least 18 gallons useable). My only
> immediate change was to push the mixture to full rich, which had no
effect.
> When I touched the throttle to add power, the RPM dropped. Gently, I
> returned the throttle and the power evened out.
>
>
>
> 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. My next move was carb heat, even though there
was
> absolutely no visible moisture. It did smooth out the roughness slightly,
> but did nothing for the power loss.
>
>
>
> The engine was dying, and the math was simple. Sink at 500 fpt, 6,800 feet
> gives me about 13 minutes and at 60 kts, I'd get about 15 statute miles. I
> knew I could make the highway without an engine.
>
>
>
> I've personally had experience looking for downed aircraft in the Florida
> swamp, and know how difficult it is to spot a small plane. We needed to
let
> someone know our position and situation. We had the skill to find the
> closest airport but every moment was precious. ATC could save valuable
> minutes and that might make the difference. With this in mind, I hit the
> radio's flip-flop button and announced our tail number on the emergency
> frequency.
>
>
>
> The Controller was a true professional. He asked me a few questions and
> instructed me to "ident" before assigning a squawk code. The radio
reception
> was not clear, which generated a stream of "say agains". This, of course
> added to the general stress of the situation.
>
>
>
> 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.
>
>
>
> Trimmed back to slow flight, we managed to barely maintain altitude. We
> arrived at the 10,500 foot runway with 3,200 feet of altitude and 120 kts
of
> air speed. I figure I could have made 4 complete turns around the pattern
> and still land hot. I have never been so relieved in my entire life.
>
>
>
> On the ground, we taxied to an area near two other planes. Relieved and
> curious I did a runup and the engine gave a text book performance.
>
>
>
> Our cell phones didn't work so we called the FBO on the radio. We were
> invited into the small building nearby where there was a phone. There we
> learned that the other two planes had landed the day before with similar
> symptoms.
>
>
>
> I phoned my mechanic and relayed the story. He gave me some great advice
and
> a definite suggestion about what caused the problem. We returned to the
> plane to follow my mechanics instructions.
>
>
>
> Another mechanic, who had come to pick up one of the other downed planes
> kindly offered to look at my engine. He pulled the cowl open, checked the
> cables on the throttle, carb heat and mixture. He sat in the 152 with me
> while I did a regular and then full-power run up. The engine showed great
> response to throttle, the mixture choked it and the carb heat performed as
> advertised.
>
>
>
> This qualified mechanic was planning to fly out in a plane that landed in
> the same condition as ours. They offered us a ride if we were not
> comfortable flying our 152. We had options. Now, we had to make a decision
> to take the ride or hop in our plane and head out.
>
>
>
> The logic was: someone at some point would fly our 152 out, and we would
> again need to fly this same plane at some point ourselves. If we waited,
> what would be different? A qualified mechanic not only said it was safe,
but
> was flying out a plane in the same condition. We decided the problem had
> resolved itself. We would fly.
>
>
>
> After a lengthy check, we headed for the runway. I did a steep climb over
> the field, continued uphill after completing a long, slow circuit of the
> airport, and headed north with a 500 FPM climb. All the while, I knew I
> could glide back to the runway if needed.
>
>
>
> It was late to start our day in the Keys so we turned towards home. When
We
> sighted I75, I knew I was home free. If there was trouble we were
guaranteed
> a level spot to land. We made Lantana at full power with no sign of the
> earlier problem.
>
>
>
> I must say, I am impressed with the FAA system and the people who dedicate
> their careers to the safety of our skies. This system that trains and
relies
> on the good judgment of the individual pilot also supports the decisions
> necessary in crisis. While part of the mandate of the FAA is to enforce
the
> laws, a pilot's decisions are respected even when they are examined. I
find
> great comfort in the FAA and the service it provides to general aviation.
>
>
>
> If our highways resembled our skies, perhaps the average driver would be
> less likely to knowingly break the law.
>
>
>
> Here's my question to this group. What caused the engine failure? More
than
> one thought is welcome, but please explain your answer. I have one of two
> possibilities in my head, and invite any questions, advise, opinions, or
> wisdom.
>
>
>
> Warm regards from one very happy pilot.
>
>
>
> Marty
>
>
>
>

[nrp]

I sometimes check mags at cruise power in the air - but only over flat
country. I also occasionally check them at idle on the ground to keep
track of the condition of the points.

One caveat is if you get a rough engine that is fixed by going to one
mag, don't experiment with the BOTH position again. One fellow I knew
did that on a 182 and had an exposion in the intake manifold that blew
off some of the intake system hoses. The integrity of the intake
system is critical to maintaining a semblance of the correct mixture
and the open port(s) made things so lean he couldn't recover power.

The range of spark ignitable mixture is less than three to one air/fuel
ratio (from about 8:1 to maybe 20:1 by weight).

[tony roberts]

Good point Scott



> I think that everyone here is pretty much in agreement that carb ice
> is suspect numero uno here. But there is something that I teach my
> students to do is immediately pull the carb heat (and leave it on)
> while you are setting up for best glide and looking for a suitable
> landing site. It takes a tenth of a second to reach and pull that
> knob. The longer you wait to do this, the cooler the engine is
> getting and carb heat becomes less effective. Then after you have
> obtained best glide and you are heading for your landing site, then go
> through the troubleshooting and preparing for an emergency landing.

--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE

[tony roberts]

> 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.

Nah - those cuddly little guys?
Didn'y ya ever watch Croc Hunter of Croc Dundee?
Ain't those 'gators even more cuddly? :):):)


We got bears.
Grizzlies, brown, black, Kodiak, and - for a real thrill - Polar.
We're what is known in aviation circles as carb-heat obsessive
compulsive :)

Didya ever see a musk-ox in mating season?
More carb heat - More carb heat . . . . :)

Tony ;)


--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE

[David Lesher]

"nrp" > writes:

>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 ....


I was going to ask about that. A lean engine runs hotter than a rich
one. But that's mostly EGT, and I'm not sure it will work back
enough to alter the carb temp. What say you folks?

--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

[George Patterson]

David Lesher wrote:
>
> I was going to ask about that. A lean engine runs hotter than a rich
> one. But that's mostly EGT, and I'm not sure it will work back
> enough to alter the carb temp. What say you folks?

On the Maule I had, the carb heat comes from a muff on one of the exhaust pipes,
so higher EGTs should produce more heat.

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

[[email protected]]

On 4-May-2005, Scott D. <> wrote:

> The longer you wait to do this, the cooler the engine is
> getting and carb heat becomes less effective.


I agree that applying carb heat quickly after experiencing power loss is
critical, but not because the ENGINE cools rapidly -- it doesn't. The heat
for carb heat comes from he exhaust system, which does cool rapidly if the
engine is producing little or no power.

--
-Elliott Drucker

[Scott D.]

On Thu, 05 May 2005 05:59:42 GMT, wrote:

>On 4-May-2005, Scott D. <> wrote:
>
>> The longer you wait to do this, the cooler the engine is
>> getting and carb heat becomes less effective.
>
>
>I agree that applying carb heat quickly after experiencing power loss is
>critical, but not because the ENGINE cools rapidly -- it doesn't. The heat
>for carb heat comes from he exhaust system, which does cool rapidly if the
>engine is producing little or no power.

Your right. My whole point was that you are no longer producing heat
thus things start cooling down. Yes, I know that carb heat comes from
a shroud that is around the exhaust. I didnt think that I had to get
technical here. But I guess for some I have to.

Scott D

To email remove spamcatcher's

[Ross Richardson]

wrote:

snip
>
> I've had instances of mag failure where switching to one improved the
> situation quite a bit. One was a bad timing gear that did include the
> backfiring, but another was a shorting distributer block that made the
> engine extremely rough and caused a power loss. In that case, I
> switched to the good mag and had a much less worriesome ride home.
>
> I guess I don't completely understand your (or Marty's) reluctance to
> at least check the mags in flight. Even at best glide, the engine is
> not going to come to a stop because you grounded a mag. If it gets
> worse, you just switch back, then try the other one. At some point,
> you decide which combo (left, right, or both) works best and you leave
> it there.
>
> Maybe there is something I haven't considered. If so, I would
> welcome enlightenment.
>
> John Galban=====>N4BQ (PA28-180)
>

Years ago I was flying a C-150 and it started running real rough. I did
an airborne mag check and found it ran better on one mag. I flew the
remainder of the trip (about 40 minutes) that way and reported this to
the FBO. Can't remember now what the problem was.
--
Regards, Ross
C-172F 180HP

[[email protected]]

On 5-May-2005, Scott D. <> wrote:

> >I agree that applying carb heat quickly after experiencing power loss is
> >critical, but not because the ENGINE cools rapidly -- it doesn't. The
> >heat
> >for carb heat comes from he exhaust system, which does cool rapidly if
> >the
> >engine is producing little or no power.
>
> Your right. My whole point was that you are no longer producing heat
> thus things start cooling down. Yes, I know that carb heat comes from
> a shroud that is around the exhaust. I didnt think that I had to get
> technical here. But I guess for some I have to.


I'm not trying to be picky. On the other hand, I think it's just a good
idea that if we intend to share knowledge on this newsgroup that we be as
accurate as possible. Of course YOU know it's really the exhaust system
that provides the heat, but some less experienced pilots or pilot wannabes
may not. From a safety standpoint, this is not a trivial point.

--
-Elliott Drucker

[Scott D.]

On Thu, 05 May 2005 18:14:30 GMT, wrote:

>
>On 5-May-2005, Scott D. <> wrote:
>
>> >I agree that applying carb heat quickly after experiencing power loss is
>> >critical, but not because the ENGINE cools rapidly -- it doesn't. The
>> >heat
>> >for carb heat comes from he exhaust system, which does cool rapidly if
>> >the
>> >engine is producing little or no power.
>>
>> Your right. My whole point was that you are no longer producing heat
>> thus things start cooling down. Yes, I know that carb heat comes from
>> a shroud that is around the exhaust. I didnt think that I had to get
>> technical here. But I guess for some I have to.
>
>
>I'm not trying to be picky. On the other hand, I think it's just a good
>idea that if we intend to share knowledge on this newsgroup that we be as
>accurate as possible. Of course YOU know it's really the exhaust system
>that provides the heat, but some less experienced pilots or pilot wannabes
>may not. From a safety standpoint, this is not a trivial point.


Point taken :)

Scott D

To email remove spamcatcher's

[[email protected]]

I've had real bad carb ice two times in a C-150 on perfectly clear
days. Both times the conditions were similar to yours. One time at
6500 feet; one time at 8500; about 70 degrees on the ground and about
42-44 at my cruising level each time, and also in the south. I got
detailed weather information from Shaw AFB WX after I got back each
time which showed relative humidity at my cruising altitude was just
over fifty percent on both occasions, despite the beautiful clear skies
and great visibility. This is when carb ice sneaks up on you and hits
you hard, leaving you shocked and in disbelief, trying other solutions
and cursing your mechanic.

One time the carb heat cured the situation very quickly, the other it
took quite a while and I had to keep adjusting mixture. When you have
carb ice the mixture changes as the ice builds up and again as it melts
away which sometimes has you "chasing" the engine with throttle and
mixture manipulations to keep it running.

I didn't read all the other posts and it may have been mentioned
already but it's important to get full throttle in right away when
dealing with carb ice also.

In 3000 hrs flying mostly small piston planes I've learned to
immediately pull carb heat full out and leave it out at any burble,
hesitation, slow down or silence! Once you've got the carb heat
engaged, go to full throttle if you haven't already and adjust mixture
for best power -- you may have to keep adjusting the mixture several
times as the shape of your venturi/level of blockage changes from ice
melting or, (GASP) growing because your carb heat is inop or
insufficient.

- Brett Justus, ATP, G/S MEI/CFII, ASC