Big fright in initial climb

[Dood]

Hie,

 

Yesterday, I was proceeding some traffic circuit, During the last one, when I reduced the power, My instructor heard a little "Pop", but nothing happened,

 

after a touch and go,during the initial climb at 250ft AGL My plane began to vibrate dangerously and run out to power. We heard a metallic click, maybe inside the engine, maybe it could be the cold flaps with vibrate against the exhaust .

the performed a emergency landing and shut dois the engine,

few minutes aft, we performed a fix point and nothing seemed unusual.

the plane is grounded

this is the link for flight data  https://www.savvyanalysis.com/my-flights/1002629/655a6886-3e90-4a59-96eb-58b6f401e234

 

Does someone have an idea ?

 

Thanks

[salty]

I am a complete amateur at this type of analysis. I'm posting what I came up with more to learn by being corrected, don't take any of this as experienced feedback. I'm also not certain I'm even looking at the event you're describing  

It doesn't seem to me like an engine problem. Rpm and hp follow mp as expected, temps pressures, fuel flow, etc don't say anything interesting to me here. 

What I notice is that in the last takeoff ground speed and altitude both peter out, but engine rpm doesn't. It seems like an increase in drag to me. Flaps fully engaged or the gear didn't go up or something?

Edited February 20, 2017 by salty

[Jeff_S]

Looking at your second-to-last flight on the log list, which I think was the problem flight, there is certainly something that happens to #4 cylinder on your last climb out. You can see a dramatic drop in both EGT and CHT that wasn't there on the other repetitions. If #4 wasn't firing at all, then that would cause vibration that you experienced. Now, as to why #4 would go out like that, perhaps a clogged fuel injector? That can cause intermittent power loss in a cylinder. 

[salty]

14 minutes ago, Jeff_S said:

Looking at your second-to-last flight on the log list, which I think was the problem flight, there is certainly something that happens to #4 cylinder on your last climb out. You can see a dramatic drop in both EGT and CHT that wasn't there on the other repetitions. If #4 wasn't firing at all, then that would cause vibration that you experienced. Now, as to why #4 would go out like that, perhaps a clogged fuel injector? That can cause intermittent power loss in a cylinder. 

Yes. I looked at EGT and CHT on the last log, not the second to last one. Good call. It's interesting to me though that the rpm didn't drop. I suppose that's because there wasn't as much load on the engine because the climb was aborted?

Edited February 20, 2017 by salty

[ArtVandelay]

I have the same issue, cylinder 4, first at startup:

It resolved itself, I did an extensive ground run, mostly rich, then on take off, something wasn't right:

I did an extensive leaned runup, 2nd takeoff was normal
I pulled injector, plugs afterwards, both look clean, had my AP do wobble test, no problem. Borescope the exhaust valve, it looked fine, my engine has 1980 hours since new, never been touched. I think the injector was clogged on startup and the extensive ground run gummed up the plugs.

[Bartman]

Regarding the next to last flight....

I am no expert either, but on the #4EGT was much higher at around 1500 while the others were about the normal 1250 range for takeoff. I think you were running on one plug on #4 for about 30 minutes, then the other plug dropped out, followed by some erratic readings. My guess is you have the A3B6D and there is something in the magneto related to #4. 

[triple8s]

Rpm would stay constant unless it dropped below a set threshold because you have a prop gov. controlling a "constant" speed prop. Power is reduced rpm stays constant, power is increased rpm stays constant hence constant speed prop. The prop gov doesnt know why the power is reduced, pilot changes power setting or engine fault resulting in less power produced, the gov will still attempt to maintain the rpm set by the prop gov control.

[Bartman]

Also, I think there is evidence of a problem with #4 EGT on the 1/20/17 flight beginning about 35 minutes into the flight. At that point it is abruptly higher than the remaining 3 EGTs with corresponding drop in #4 CHT. 

[mooniac15u]

18 minutes ago, Bartman said:

Also, I think there is evidence of a problem with #4 EGT on the 1/20/17 flight beginning about 35 minutes into the flight. At that point it is abruptly higher than the remaining 3 EGTs with corresponding drop in #4 CHT. 

What happened at 57 minutes into that flight on 1/20/17?  Massive drop in 3 out of 4 EGTs and 2 out of 4 CHTs.

[M016576]

Plugged #4 injector, possible blown gasket (the pop)

[salty]

1 hour ago, triple8s said:

Rpm would stay constant unless it dropped below a set threshold because you have a prop gov. controlling a "constant" speed prop. Power is reduced rpm stays constant, power is increased rpm stays constant hence constant speed prop. The prop gov doesnt know why the power is reduced, pilot changes power setting or engine fault resulting in less power produced, the gov will still attempt to maintain the rpm set by the prop gov control.

Duh. Thanks. I missed that completely.

[Greg_D]

How old is the sealant in your fuel tanks?  I had the same issue on an F model and found a piece of the old sealant in one of the fuel nozzles.

[Dood]

What happened at 57 minutes into that flight on 1/20/17?  Massive drop in 3 out of 4 EGTs and 2 out of 4 CHTs.

Just an electrical interference With co-pilot Push-to-talk switch


Envoyé de mon iPad en utilisant Tapatalk

[Dood]

How old is the sealant in your fuel tanks?  I had the same issue on an F model and found a piece of the old sealant in one of the fuel nozzles.

I don't Know


Envoyé de mon iPad en utilisant Tapatalk

[Dood]

This is the savvy analyze

Cyrille de Crépy

Hi Cyrille
Sorry to hear about your emergency event and very lad you were able ti get back down safely. Cyl #4 flamed out on you for almost a couple minutes. It did come back online,
We can see the issue is Cyl #4 and this began on your Jan 20th flight.
Without diagnostic Savvy Test profile flight data we can be sure what the issue is. I tried to use what appeared to be your ground run-up before takeoff but there was no time between the two mags to see any thing there either. What we really suspect is that you are firing a single plug in #4 and then on your recent flight the other plug temporarily fowled so that the cylinder flamed out for a couple minutes. If its not ignition we could have a mixture issue but right now the ignition issue looks most likely.
So I suggest we first try to verify by doing another ground run up. But this time lets have you lean it out when you do the run up. Advance the throttle to your normal runup rpm, then lean it out but not so lean it causes any missing roughness. Thus you might lean to missing roughness and then enrich just enough back to be smooth. Then very importantly after a couple seconds of allowing temps to stabilize leaned at runup rpm, place the analyzer in Normalize mode. (see your documentation if that is unfamiliar to you) Now go to each mag position for 30 secs including Both in the middle for 30 sec to allow all EGTs to comeback down before switching to the other single mag.
I suspect you will see #4 not rise from the Both baseline temp on one of the single mag positions, and while on the other single mag you will see it drop in temp and feel roughness.
If so, that shows us which plug is dead.
Hopefully that's all it is.
Its possible we could have a weak plug that only acts up under higher power which begs for an inflight LOP magneto test.
But what we're seeing in #4 is that EGT went elevated back in Jan 20 which is most likely due to a failed plug. But a overly lean mixture could cause that as well, such as partially plugged injector or an induction leak at #4. But let's start with the more likely plug issue.
Let us know what you find,
Paul Kortopates


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[Marauder]

This is the savvy analyze

 

Cyrille de Crépy

 

Hi Cyrille

Sorry to hear about your emergency event and very lad you were able ti get back down safely. Cyl #4 flamed out on you for almost a couple minutes. It did come back online,

We can see the issue is Cyl #4 and this began on your Jan 20th flight.

Without diagnostic Savvy Test profile flight data we can be sure what the issue is. I tried to use what appeared to be your ground run-up before takeoff but there was no time between the two mags to see any thing there either. What we really suspect is that you are firing a single plug in #4 and then on your recent flight the other plug temporarily fowled so that the cylinder flamed out for a couple minutes. If its not ignition we could have a mixture issue but right now the ignition issue looks most likely.

So I suggest we first try to verify by doing another ground run up. But this time lets have you lean it out when you do the run up. Advance the throttle to your normal runup rpm, then lean it out but not so lean it causes any missing roughness. Thus you might lean to missing roughness and then enrich just enough back to be smooth. Then very importantly after a couple seconds of allowing temps to stabilize leaned at runup rpm, place the analyzer in Normalize mode. (see your documentation if that is unfamiliar to you) Now go to each mag position for 30 secs including Both in the middle for 30 sec to allow all EGTs to comeback down before switching to the other single mag.

I suspect you will see #4 not rise from the Both baseline temp on one of the single mag positions, and while on the other single mag you will see it drop in temp and feel roughness.

If so, that shows us which plug is dead.

Hopefully that's all it is.

Its possible we could have a weak plug that only acts up under higher power which begs for an inflight LOP magneto test.

But what we're seeing in #4 is that EGT went elevated back in Jan 20 which is most likely due to a failed plug. But a overly lean mixture could cause that as well, such as partially plugged injector or an induction leak at #4. But let's start with the more likely plug issue.

Let us know what you find,

Paul Kortopates

 

 

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Just FYI, Paul is a contributor and fellow Mooney owner on this site. He helped me diagnose a problem similar to your problem. I fortunately caught the issue on the ground. Prior flights showed no issues. The two spark plugs in my #2 cylinder decided to start failing.

 

From the SavvyAnalysis display of my JPI data you will see two arrows I placed on it. This is a ground mag check of my plane. The red arrow shows when the spark plug on that mag completely died. Essentially running on 3 cylinders. The blue arrow shows me taxiing back to the hangar on one spark plug.

 

I pulled the plugs and checked the resistance. They (and most of the others) failed the resistance test. I replaced all of the spark plugs with Tempest fine wires.

 

 

 

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[carusoam]

What to do next?

Paul at Savvy indicates...

1) Run-up procedure can be run better to see the data more clearly.  Add 20 seconds between each step both, right, both, left, both...

2) even without a clear run-up, there seems to be at least one bad spark plug.

 

Typical JPI data collection takes one data point every 6 seconds.  Too slow to catch data unless you wait extra long...

 

Typical spark plug issues are made by Champion.  Check the resistance of the plugs.  Often they become too high resistance on their own.  They look right.  But they are not right.

 

Something that can be done now....

perform a run-up on the ground with extended run time between different mag selections.  Verify the rise on each of the EGTs when a single mag is operating.  This should clearly show which is a bad plug.

measure the resistance of the bad plug, read the name of the manufacturer of the plug.

 

theses are Private pilot ideas, not from a mechanic.  Ideas that have been seen here before.

 

Continue to use Savvy as a tool to determine what is really going on inside your engine.

people have posted pictures of all their spark plugs.

people have measured and posted the resistance on all of their spark plugs.

 

the other issues mentioned...

1) fuel blockage in the fuel injectors.  There is a test for that using baby food jars to measure the flow of fuel in each injector over time.

2) check your airframe log books to see how old the sealant might be.  There is a screen at the fuel tank selector that is somewhat easy to access.  This screen/separator can often tell what is going on in the fuel tanks. Rust, dirt, and water often show up here...

3) push to talk and grounding issues disturbing the JPI data?  Time to look into the grounding straps, engine, airframe and instrument panel...

4) posting a video of what you are seeing can be done using YouTube. Consider posting a video of your run-up.

 

As I typed before....

theses are Private pilot ideas, not from a mechanic.  Ideas that have been seen here before.

Best regards,

-a-

Edited February 21, 2017 by carusoam

[Bob_Belville]

I owned a '66E from 1977 to 1988 flying it about 2500 hours. Early on I switched to fine wire plugs and I supposed I might have put 2000 hours on them. When I bought another E 5 years ago it had Champion massives. The second time I had to taxi back to the maintenance shop from the run up area with a fouled plug I ordered a set of Tempest fine wires. There is no comparison.

[thinwing]

I have also had good results with tempest fine wires.

[Dood]

and the winner is..... fuel injector #4, probably paint stripping residue of my new paint ....

 

[carusoam]

Great Pirep, Dood.

Continue to monitor the other issues in case there were more than the one you found...

Best regards,

-a-

Edited March 4, 2017 by carusoam

[Stephen]

On 3/4/2017 at 0:36 AM, carusoam said:

Great Pirep, Dood.

Continue to monitor the other issues in case there were more than the one you found...

Best regards,

-a-

....and send some Dijon to Paul  

[Johnnybgoode]

+ 1 for Savvy!

Patrick

[Raptor05121]

Awesome diagnosis and result! Check the others as well?