Mooney Engine Problem in Flight - Advise

[Paul Smedshammer]

This is a bit long winded but I'm looking for qualified opinions as to what
might have happed to an almost total loss of power while in cruise flight in
my Mooney M20F. Here is the story of what happened:

I was flying from Turlock (south of Modesto) to Petaluma (north of San
Francisco) on a Saturday. Weather was strange with a thick mist and fog layer
from about 500 feet to 2000 feet. I was VFR on top and there were no holes
anywhere through the fog/clouds/mist.

Prior to the flight, I sumped the wings with no indication of any water. I
did a normal run up and there were no issues at all. I was running on the
left tank which is what I had run on for the last 1/2 of the flight the night
before. Left tank had about 20 gallons right tank about 30. Take off was no
issue and full power was available with a good sounding engine. I found a
hole in the clouds and climbed to 4,500 on a heading direct to Petaluma.
About eight minutes into the flight (from take off), suddenly but not sudden
like a switch or electrical problem I would guess power output dropped to
around 30% with a decent engine vibration. It felt and acted as if two
sparkplug wires were simultaneously pulled from the plugs. I noticed the EGT
that I had leaned to 1320 F was now down to below 1000 F. I checked the mags
and there was no difference in operation between both, 1 or 2. I pushed the
throttle in full with no effect. I switched tanks to the right wing with no
effect. I turned on the boost pump with no effect. I opened the power boost
which bypasses the air filter which resulted in a tiny bit of improvement
maybe getting me up to 35% power. I moved the mixture in full rich and it
smoothed out considerably and I would guess power output moved up to say 45%.
My speed leveled off at around 124 knots from the 151 it was just prior. I
was able to hold 4,500 feet. EGT rose only about to 1100 F. I contacted
NorCal and advised them of my situation. They were great and offered vectors
to Modesto that I was right on top of according to the GPS. I advised them
that it was totally socked in fog that spread about 20 miles in all
directions. After about 30 seconds later I slowly moved the mixture out and
it began running extremely rough with no increase in EGT so I pushed it back
in scared that I would make it worse and loose my 45% power output. NorCal
asked what I wanted to do and as airspeed was being held, it was producing
about 45% power and I was holding altitude I told them I would forge ahead. I
felt this was less risky than dropping through the fog layer into 3 miles of
mist visibility with engine problems trying to find a runway with towers up
around 500 feet in the area. Time is strange and I'm guessing after about 5
minutes of this, I felt the plane pull forward like there was a significant
power increase and I noticed the EGT move up to 1190 F. I leaned it a little
and EGT went up to 1200 F max and quickly began to run rough so I slid it back
in to full rich. After about 3 more minutes I would say the power seemed to
up around 60% and I tried leaning again. This time it leaned like always
rising to a maximum of about 1410 F before running rough so I backed off to
run around 1310 F - normal operation. The whole event from the start of
something being wrong to full power being restored was I would say around 10
minutes. Maybe a little less. From that point on it was like nothing was
wrong. Remaining 30 minutes of the flight went without a hitch and the engine
responded just like it should and always has. I can only think that there was
some water stuck somewhere in the wing behind one of the baffles and the
engine just had to work through it. I can't think of anything else that could
have caused this behavior.

The following day I went out and did 10 sumps of each tank and the center
sump. None showed any sign of water. If it was a bad mag I would have
expected to loose the engine completely when I went to mag 1 or mag 2 but I
didn't. Only thing I can come up with is either water in the tank or an
obstruction in the line.

The engine problem would not have been so critical if I wasn't VFR on top.
Without an engine and VFR on top you have very little options.

Thanks for your opinions and advise. Please post any responses here.

Mooney M20F

PS. Other info is that fuel consumption was normal and I'm at just now at 6
qts of oil remaining after 16.5 hours since last oil change. So that works
out to be about 11.8 hours per qt. No other indications of problems. Except
of course the oil and gas dripping out of the plenum drain after stopping the
engine. Engine has about 80 hours since LMOH and has worked perfectly.

[kage]

"Paul Smedshammer" > wrote in message
. com...
> This is a bit long winded but I'm looking for qualified opinions as to
> what
> might have happed to an almost total loss of power while in cruise flight
> in
> my Mooney M20F. Here is the story of what happened:
>
> I was flying from Turlock (south of Modesto) to Petaluma (north of San
> Francisco) on a Saturday. Weather was strange with a thick mist and fog
> layer
> from about 500 feet to 2000 feet. I was VFR on top and there were no
> holes
> anywhere through the fog/clouds/mist.
>
> Prior to the flight, I sumped the wings with no indication of any water.
> I
> did a normal run up and there were no issues at all. I was running on the
> left tank which is what I had run on for the last 1/2 of the flight the
> night
> before. Left tank had about 20 gallons right tank about 30. Take off was
> no
> issue and full power was available with a good sounding engine. I found a
> hole in the clouds and climbed to 4,500 on a heading direct to Petaluma.
> About eight minutes into the flight (from take off), suddenly but not
> sudden
> like a switch or electrical problem I would guess power output dropped to
> around 30% with a decent engine vibration. It felt and acted as if two
> sparkplug wires were simultaneously pulled from the plugs. I noticed the
> EGT
> that I had leaned to 1320 F was now down to below 1000 F. I checked the
> mags
> and there was no difference in operation between both, 1 or 2. I pushed
> the
> throttle in full with no effect. I switched tanks to the right wing with
> no
> effect. I turned on the boost pump with no effect. I opened the power
> boost
> which bypasses the air filter which resulted in a tiny bit of improvement
> maybe getting me up to 35% power. I moved the mixture in full rich and it
> smoothed out considerably and I would guess power output moved up to say
> 45%.
> My speed leveled off at around 124 knots from the 151 it was just prior.
> I
> was able to hold 4,500 feet. EGT rose only about to 1100 F. I contacted
> NorCal and advised them of my situation. They were great and offered
> vectors
> to Modesto that I was right on top of according to the GPS. I advised
> them
> that it was totally socked in fog that spread about 20 miles in all
> directions. After about 30 seconds later I slowly moved the mixture out
> and
> it began running extremely rough with no increase in EGT so I pushed it
> back
> in scared that I would make it worse and loose my 45% power output.
> NorCal
> asked what I wanted to do and as airspeed was being held, it was producing
> about 45% power and I was holding altitude I told them I would forge
> ahead. I
> felt this was less risky than dropping through the fog layer into 3 miles
> of
> mist visibility with engine problems trying to find a runway with towers
> up
> around 500 feet in the area. Time is strange and I'm guessing after about
> 5
> minutes of this, I felt the plane pull forward like there was a
> significant
> power increase and I noticed the EGT move up to 1190 F. I leaned it a
> little
> and EGT went up to 1200 F max and quickly began to run rough so I slid it
> back
> in to full rich. After about 3 more minutes I would say the power seemed
> to
> up around 60% and I tried leaning again. This time it leaned like always
> rising to a maximum of about 1410 F before running rough so I backed off
> to
> run around 1310 F - normal operation. The whole event from the start of
> something being wrong to full power being restored was I would say around
> 10
> minutes. Maybe a little less. From that point on it was like nothing was
> wrong. Remaining 30 minutes of the flight went without a hitch and the
> engine
> responded just like it should and always has. I can only think that there
> was
> some water stuck somewhere in the wing behind one of the baffles and the
> engine just had to work through it. I can't think of anything else that
> could
> have caused this behavior.
>
> The following day I went out and did 10 sumps of each tank and the center
> sump. None showed any sign of water. If it was a bad mag I would have
> expected to loose the engine completely when I went to mag 1 or mag 2 but
> I
> didn't. Only thing I can come up with is either water in the tank or an
> obstruction in the line.
>
> The engine problem would not have been so critical if I wasn't VFR on top.
> Without an engine and VFR on top you have very little options.
>
> Thanks for your opinions and advise. Please post any responses here.
>
> Mooney M20F
>
> PS. Other info is that fuel consumption was normal and I'm at just now at
> 6
> qts of oil remaining after 16.5 hours since last oil change. So that
> works
> out to be about 11.8 hours per qt. No other indications of problems.
> Except
> of course the oil and gas dripping out of the plenum drain after stopping
> the
> engine. Engine has about 80 hours since LMOH and has worked perfectly.



Sounds like water to me.

My Mooney M20J sat outside for a year. The only way to completely remove the
water in the wings was to raise or lower the wings. I did this by
positioning one of the main wheels over a drain in the pavement, which gave
me about a 3 degree bank. Much more water could be removed this way. I
supose you could use a small jack on one side with better results.

I also stuck rubber pads (rubber door mats) over the fuel caps, to keep rain
from running past the crummy (even when new) rubber fuel cap seals when tied
down.

Water problem went away when I got a hangar.

Karl
"Curator" N185KG

[Elwood Dowd]

Definitely sounds like indigestion. Either water (it's tough to get it
all out in a Mooney) or some particle that eventually made it through
the injectors.

[Almarz]

Whew!!!

Water or something clogging the injectors would be my guess!

On Mon, 13 Dec 2004 03:45:18 GMT,
(Paul Smedshammer) wrote:

>This is a bit long winded but I'm looking for qualified opinions as to what
>might have happed to an almost total loss of power while in cruise flight in
>my Mooney M20F. Here is the story of what happened:
>
>I was flying from Turlock (south of Modesto) to Petaluma (north of San
>Francisco) on a Saturday. Weather was strange with a thick mist and fog layer
>from about 500 feet to 2000 feet. I was VFR on top and there were no holes
>anywhere through the fog/clouds/mist.
>
>Prior to the flight, I sumped the wings with no indication of any water. I
>did a normal run up and there were no issues at all. I was running on the
>left tank which is what I had run on for the last 1/2 of the flight the night
>before. Left tank had about 20 gallons right tank about 30. Take off was no
>issue and full power was available with a good sounding engine. I found a
>hole in the clouds and climbed to 4,500 on a heading direct to Petaluma.
>About eight minutes into the flight (from take off), suddenly but not sudden
>like a switch or electrical problem I would guess power output dropped to
>around 30% with a decent engine vibration. It felt and acted as if two
>sparkplug wires were simultaneously pulled from the plugs. I noticed the EGT
>that I had leaned to 1320 F was now down to below 1000 F. I checked the mags
>and there was no difference in operation between both, 1 or 2. I pushed the
>throttle in full with no effect. I switched tanks to the right wing with no
>effect. I turned on the boost pump with no effect. I opened the power boost
>which bypasses the air filter which resulted in a tiny bit of improvement
>maybe getting me up to 35% power. I moved the mixture in full rich and it
>smoothed out considerably and I would guess power output moved up to say 45%.
>My speed leveled off at around 124 knots from the 151 it was just prior. I
>was able to hold 4,500 feet. EGT rose only about to 1100 F. I contacted
>NorCal and advised them of my situation. They were great and offered vectors
>to Modesto that I was right on top of according to the GPS. I advised them
>that it was totally socked in fog that spread about 20 miles in all
>directions. After about 30 seconds later I slowly moved the mixture out and
>it began running extremely rough with no increase in EGT so I pushed it back
>in scared that I would make it worse and loose my 45% power output. NorCal
>asked what I wanted to do and as airspeed was being held, it was producing
>about 45% power and I was holding altitude I told them I would forge ahead. I
>felt this was less risky than dropping through the fog layer into 3 miles of
>mist visibility with engine problems trying to find a runway with towers up
>around 500 feet in the area. Time is strange and I'm guessing after about 5
>minutes of this, I felt the plane pull forward like there was a significant
>power increase and I noticed the EGT move up to 1190 F. I leaned it a little
>and EGT went up to 1200 F max and quickly began to run rough so I slid it back
>in to full rich. After about 3 more minutes I would say the power seemed to
>up around 60% and I tried leaning again. This time it leaned like always
>rising to a maximum of about 1410 F before running rough so I backed off to
>run around 1310 F - normal operation. The whole event from the start of
>something being wrong to full power being restored was I would say around 10
>minutes. Maybe a little less. From that point on it was like nothing was
>wrong. Remaining 30 minutes of the flight went without a hitch and the engine
>responded just like it should and always has. I can only think that there was
>some water stuck somewhere in the wing behind one of the baffles and the
>engine just had to work through it. I can't think of anything else that could
>have caused this behavior.
>
>The following day I went out and did 10 sumps of each tank and the center
>sump. None showed any sign of water. If it was a bad mag I would have
>expected to loose the engine completely when I went to mag 1 or mag 2 but I
>didn't. Only thing I can come up with is either water in the tank or an
>obstruction in the line.
>
>The engine problem would not have been so critical if I wasn't VFR on top.
>Without an engine and VFR on top you have very little options.
>
>Thanks for your opinions and advise. Please post any responses here.
>
>Mooney M20F
>
>PS. Other info is that fuel consumption was normal and I'm at just now at 6
>qts of oil remaining after 16.5 hours since last oil change. So that works
>out to be about 11.8 hours per qt. No other indications of problems. Except
>of course the oil and gas dripping out of the plenum drain after stopping the
>engine. Engine has about 80 hours since LMOH and has worked perfectly.

[Grumman 236]

Paul Smedshammer wrote:
> This is a bit long winded but I'm looking for qualified opinions as
to what
> might have happed to an almost total loss of power while in cruise
flight in
> my Mooney M20F. Here is the story of what happened:
Almost sounds like induction icing.

[Paul Smedshammer]

In article om>, "Grumman 236" > wrote:
>
>Paul Smedshammer wrote:
>> This is a bit long winded but I'm looking for qualified opinions as
>to what
>> might have happed to an almost total loss of power while in cruise
>flight in
>> my Mooney M20F. Here is the story of what happened:
>Almost sounds like induction icing.
>

A couple of folks have mentioned induction icing. Being a relatively new pilot
to the Mooney and more specifically fuel injection, I wasn't aware that icing
was a big problem in the fuel injection engines. There is no "carb. heat" as
there is no carburetor. Maybe somebody can elaborate and educate me on icing
in the induction system and what you can do to avoid it.

Temps above the fog layer which I was 2,500 feet above were in the 60's so I
didn't figure icing could have been a factor.

[zatatime]

On Mon, 13 Dec 2004 16:44:33 GMT,
(Paul Smedshammer) wrote:

>A couple of folks have mentioned induction icing. Being a relatively new pilot
>to the Mooney and more specifically fuel injection, I wasn't aware that icing
>was a big problem in the fuel injection engines. There is no "carb. heat" as
>there is no carburetor. Maybe somebody can elaborate and educate me on icing
>in the induction system and what you can do to avoid it.
>
>Temps above the fog layer which I was 2,500 feet above were in the 60's so I
>didn't figure icing could have been a factor.

I think this is the correct "guess." Induction icing can occur in the
60 degree range without a problem if you have the right conditions
(i.e. moisture, which you had alot of). In your original post you
stated you put on an alternate air source of some sort to bypass the
air filter. Check with your mechanic if this gives heated air to the
mixture. If so this is the equivalent of carb heat, and could be how
the problem resolved itself. If not, check to see how to provide warm
air to the induction system. Even if you've got to make a
modification (install something), it'll be worth it.

HTH.
z

[Paul Smedshammer]

In article >, zatatime > wrote:
> On Mon, 13 Dec 2004 16:44:33 GMT,
>(Paul Smedshammer) wrote:
>
>>A couple of folks have mentioned induction icing. Being a relatively new
> pilot
>>to the Mooney and more specifically fuel injection, I wasn't aware that icing
>>was a big problem in the fuel injection engines. There is no "carb. heat" as
>>there is no carburetor. Maybe somebody can elaborate and educate me on icing
>>in the induction system and what you can do to avoid it.
>>
>>Temps above the fog layer which I was 2,500 feet above were in the 60's so I
>>didn't figure icing could have been a factor.
>
>I think this is the correct "guess." Induction icing can occur in the
>60 degree range without a problem if you have the right conditions
>(i.e. moisture, which you had alot of). In your original post you
>stated you put on an alternate air source of some sort to bypass the
>air filter. Check with your mechanic if this gives heated air to the
>mixture. If so this is the equivalent of carb heat, and could be how
>the problem resolved itself. If not, check to see how to provide warm
>air to the induction system. Even if you've got to make a
>modification (install something), it'll be worth it.
>
>HTH.
>z

The Mooney M20F and many of the other older models (pre 1976 and post 1965 I
think) have a Power Boost which is nothing more than an air filter bypass. It
allows air directly into the servo and in my case provides for about a 1-1/2
to 2" increase in manifold pressure. I only use it about 4 to 5000 feet AGL
and only in clear air. There isn't any way I know of to inject warm air like
carb heat to the air source.

For those interested, here is a link to a photo of what it looked like about
10 seconds before this event happened.

http://www.coreutilities.com/mooney/RoughEngine.JPG

I'm still thinking most likely it was water contamination but it could have
also been induction icing I guess.

Thanks,
Paul

[Mike Rapoport]

"zatatime" > wrote in message
...
> On Mon, 13 Dec 2004 16:44:33 GMT,
> (Paul Smedshammer) wrote:
>
>>A couple of folks have mentioned induction icing. Being a relatively new
>>pilot
>>to the Mooney and more specifically fuel injection, I wasn't aware that
>>icing
>>was a big problem in the fuel injection engines. There is no "carb. heat"
>>as
>>there is no carburetor. Maybe somebody can elaborate and educate me on
>>icing
>>in the induction system and what you can do to avoid it.
>>
>>Temps above the fog layer which I was 2,500 feet above were in the 60's so
>>I
>>didn't figure icing could have been a factor.
>
> I think this is the correct "guess." Induction icing can occur in the
> 60 degree range without a problem if you have the right conditions
> (i.e. moisture, which you had alot of). In your original post you
> stated you put on an alternate air source of some sort to bypass the
> air filter. Check with your mechanic if this gives heated air to the
> mixture. If so this is the equivalent of carb heat, and could be how
> the problem resolved itself. If not, check to see how to provide warm
> air to the induction system. Even if you've got to make a
> modification (install something), it'll be worth it.
>
> HTH.
> z

You can't get induction icing in a fuel injected engine with temps in the
60s regardless of how much moisture is present.

Mike
MU-2

[Ron Rosenfeld]

On Mon, 13 Dec 2004 16:44:33 GMT, (Paul
Smedshammer) wrote:

>A couple of folks have mentioned induction icing. Being a relatively new pilot
>to the Mooney and more specifically fuel injection, I wasn't aware that icing
>was a big problem in the fuel injection engines. There is no "carb. heat" as
>there is no carburetor. Maybe somebody can elaborate and educate me on icing
>in the induction system and what you can do to avoid it.

Paul,

I doubt it was induction icing.

I have flown my M20E -- which has the same engine -- for 2000+ hours mostly
in the NorthEast. I have been in visible moisture not only at temps in the
60's, but also down to the 30's, with NO sign of icing.

Some folk have had problems with ice impacting on the air filter and
cutting of air flow that way. In that case, if the alternate air door
doesn't open, the engine dies.

However, that is not going to happen in 60° weather!

Again, I think you had fuel contamination or some other cause of blockage
in the fuel lines or injector nozzles. The worst case would be from
sealant breaking down in the tanks. If that's the case, you may find some
stuff on the fuel filter. You can also sometimes see debris in the fuel
when you drain the tanks.

While it could have been water, in my experience, if you had enough water
to cause an engine problem lasting as long as yours did, you should have
seen some when you sumped the tanks. (Unless it was all water and you
missed it).


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

[[email protected]]

On 13-Dec-2004, zatatime > wrote:

> I think this is the correct "guess." Induction icing can occur in the
> 60 degree range without a problem if you have the right conditions
> (i.e. moisture, which you had alot of). In your original post you
> stated you put on an alternate air source of some sort to bypass the
> air filter. Check with your mechanic if this gives heated air to the
> mixture. If so this is the equivalent of carb heat, and could be how
> the problem resolved itself. If not, check to see how to provide warm
> air to the induction system. Even if you've got to make a
> modification (install something), it'll be worth it.


Induction air heating is not required for injected engines because intake
air is not cooled like it is in a carburetor. Induction icing in an
injected engine means that frozen (i.e. snow) or super-cooled water in the
atmosphere freezes in the induction system (usually in the air filter) and
restricts airflow. The alternate air system bypasses the air filter to
solve the problem. Source of alternate air in most injected airplanes is
from within the cowling, so there is some warming effect. The Mooneys of a
certain vintage used their "Power Boost" system to double as the alternate
air, so their alternate air source is ram induction.

In this case induction icing as the problem is extremely unlikely for two
reasons. First, it is not likely to occur with an OAT in the 60 degree
range. Second, induction icing, or any other problem that restricts intake
air, would result in an excessively RICH mixture, and engine roughness would
then be reduced by LEANING the mixture. In this case engine roughness was
reduced by ENRICHING the mixture, which indicates that the problem lay not
in the intake air but in the fuel system. Water in the fuel is certainly a
possibility, but since the problem did not resolve by switching tanks
(assuming the pilot gave it a few moments for this to work before switching
back) I think a more likely culprit would be one or more partially clogged
injectors. I would have a mechanic inspect the fuel system from the
gascolator through the injectors to make sure that no contaminants remained.

--
-Elliott Drucker

[Paul Smedshammer]

In article <05mvd.4322$lZ6.4235@trnddc02>, wrote:

Thanks to everybody for your responses. Sounds like the general consensus is
either water in the fuel or some other fuel contamination. I'm taking the
plane up to LASAR to have them drain the tanks and go through the whole fuel
system. Hopefully they can find something that would explain what happened.
This sure makes me think twice about VFR on top or even night flying.

I will post what they hopefully find.

Paul,
1967 Mooney M20F

[jls]

"Paul Smedshammer" > wrote in message
om...
> In article <05mvd.4322$lZ6.4235@trnddc02>,
wrote:
>
> Thanks to everybody for your responses. Sounds like the general consensus
is
> either water in the fuel or some other fuel contamination. I'm taking the
> plane up to LASAR to have them drain the tanks and go through the whole
fuel
> system. Hopefully they can find something that would explain what
happened.
> This sure makes me think twice about VFR on top or even night flying.
>
> I will post what they hopefully find.
>
> Paul,
> 1967 Mooney M20F

200hp Lycoming, right? Monitor each cyl head and egt individually. Only
4 to monitor. You can isolate the problem better that way. You may have
had a clogged injector or two or plugs failing or valves sticking or mag or
mags malfunctioning or harness cross-arcing, or ?. Full monitoring with
memory will keep your mags, plugs, harness, valves, cam, and injection
reasonably diagnosed, away from enigmas like this one, and you more
knowledgeable and happier. Read more Deakin too.

[Paul Smedshammer]

In article >, (Paul Smedshammer) wrote:
>In article <05mvd.4322$lZ6.4235@trnddc02>, wrote:
>
>Thanks to everybody for your responses. Sounds like the general consensus is
>either water in the fuel or some other fuel contamination. I'm taking the
>plane up to LASAR to have them drain the tanks and go through the whole fuel
>system. Hopefully they can find something that would explain what happened.
>This sure makes me think twice about VFR on top or even night flying.
>
>I will post what they hopefully find.
>

I just spent 4 hours of mechanic time up at Lasar. At my request they went
through everything. Checked the tanks for water, checked the gas collator,
servo, injectors, spark plugs, exhaust for blockage, air intakes (filter,
alternate air, ram air) all without finding anything. Test flight afterward
and the flight home both had the engine running perfectly as if nothing had
ever happened. Everybody is scratching their heads a little but I'm pretty
sure the culprit was water in the tank. On the flight that I had the trouble,
I made a step bank turn to stay under the fog ahead and I'm thinking there was
some water trapped behind a rib in the wing. The steep turn could have
stirred it up and had it settle to the bottom of the tank, which then got
pulled into the engine. It ran really rough for a while as it was a mixture
(recently stirred up) of water and fuel and then when that mixture was all
pushed through, it cleared up and ran normal. Leaving no sign of what had
happened.

Lessons learned, 1) do not fly VFR Over the Top unless you absolutely have to
and if you do get a lot of altitude so you might have a chance to glide to a
clear area to land and 2) really work the wings and sump the tanks vigorously
after rain or even dense fog - or for that matter anytime before you go flying
- you might have trapped water in the wing somewhere.

Thanks again to everybody who responded. I have learned a lot through this
experience.

Paul
Mooney M20F

[Ron Rosenfeld]

On Sat, 18 Dec 2004 04:48:39 GMT, (Paul
Smedshammer) wrote:

>In article >, (Paul Smedshammer) wrote:
>>In article <05mvd.4322$lZ6.4235@trnddc02>, wrote:
>>

>I made a step bank turn to stay under the fog ahead and I'm thinking there was
>some water trapped behind a rib in the wing.

Paul,

Did they check to be sure the drain holes in the rib were not blocked by
sealant?


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

[Paul Smedshammer]

In article >, Ron Rosenfeld > wrote:
>
>>I made a step bank turn to stay under the fog ahead and I'm thinking there was
>
>>some water trapped behind a rib in the wing.
>
>Paul,
>
>Did they check to be sure the drain holes in the rib were not blocked by
>sealant?
>
>
>Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

They inspected the wing tank that I was on when this occurred. Everything
looked okay. I'm sure we will go through it in more detail during the full
annual in the Spring. Thanks again to everybody. There is a huge wealth of
knowledge in these groups and it really helps to educate everybody reading
them.

Thanks,

Paul (N3506X, 1967 Mooney M20F)

[Dave Butler]

Paul Smedshammer wrote:
>
> Lessons learned, 1) do not fly VFR Over the Top unless you absolutely have to
> and if you do get a lot of altitude so you might have a chance to glide to a
> clear area to land and 2) really work the wings and sump the tanks vigorously
> after rain or even dense fog - or for that matter anytime before you go flying
> - you might have trapped water in the wing somewhere.

You didn't mention: (since this is a Mooney) check or replace the o-rings in the
fuel filler caps frequently, perhaps twice as often as required by the AD. Also
check for corrosion of the cap mechanism preventing the o-rings from sealing
properly.

[Paul Smedshammer]

Dave Butler > wrote in
news:1103570747.387686@sj-nntpcache-5:

> You didn't mention: (since this is a Mooney) check or replace the
> o-rings in the fuel filler caps frequently, perhaps twice as often as
> required by the AD. Also check for corrosion of the cap mechanism
> preventing the o-rings from sealing properly.

Just prior to the rainy season this year I replaced all four o-rings. One
big one around the cap and the little one in the middle of the cap shaft.
You could really see the old ones were very stiff and brittle. I hear you
should replace these a couple of times a year. I think they only cost
about $8 for all four and I put them on myself in about 10 minutes.