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Mooney Engine Problem in Flight - Advise



 
 
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  #1  
Old December 13th 04, 04:45 AM
Paul Smedshammer
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Default Mooney Engine Problem in Flight - Advise

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.
  #2  
Old December 13th 04, 05:01 AM
kage
external usenet poster
 
Posts: n/a
Default


"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


  #3  
Old December 13th 04, 09:18 AM
Elwood Dowd
external usenet poster
 
Posts: n/a
Default

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.
  #4  
Old December 13th 04, 02:39 PM
Almarz
external usenet poster
 
Posts: n/a
Default

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.


  #5  
Old December 13th 04, 03:24 PM
Grumman 236
external usenet poster
 
Posts: n/a
Default


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.

  #6  
Old December 13th 04, 05:44 PM
Paul Smedshammer
external usenet poster
 
Posts: n/a
Default

In article . com, "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.
  #8  
Old December 13th 04, 06:57 PM
Paul Smedshammer
external usenet poster
 
Posts: n/a
Default

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
  #10  
Old December 13th 04, 08:14 PM
Ron Rosenfeld
external usenet poster
 
Posts: n/a
Default

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)
 




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