Not wanting to be the next Cirrus Engine failure

SixPapaCharlie said:
Plane is in annual They are "concerned about compression on 2 of the cylinders" He said they are in the 30s which I find puzzling as 3 weeks ago they said everything was in great shape.
We'll see... If there is an issue, I hope they can overhaul versus replace otherwise this is going to do bad things to my airplane fund.

airplanes are stupid.
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The last time I had bad IO550N jugs, the price delta between rebuilding and replacing was only a couple hundred dollars each. In my opinion, if it is between a couple hundred dollars, it is worth just to buy new (labor is going to be the same). If anything, it is worth the time it takes to send them away and be rebuilt.
Do you know if the compression was escaping through the rings into the crankcase, or out of the exhaust valve?
What year engine? Mine was a 2006 and had one set under warranty and I paid for the second. There is a rumor that Continental had a dark period in the 2000s where longevity in big bore cylinder heads was **** poor. In my experience, I believe it.

From Continental SID 97-2b

1. DIFFERENTIAL COMPRESSION CHECK
a. Perform Differential Compression Check in accordance with the latest revision of TCM
Service Bulletin SB03-3 and record the master orifice tool reading.
1. For cylinders with differential pressures greater than the minimum allowable
calibrated compression reading, and borescope inspection reveals no abnormalities,
then continue in service.
2. For cylinders with differential pressures less than the minimum allowable calibrated
compression reading, a borescope examination must be performed and the aircraft
flown at power with a re-check of the suspect cylinder. If the cylinder leakage rate is
still below the minimum allowable calibrated reading, the leakage source must be
determined and corrected.
3. For cylinders where leakage by the valves is identified, perform a borescope
inspection of the affected cylinder(s). If the leakage rate is above the minimum
allowable calibrated compression reading, and borescope examinations reveal no
abnormalities, continue in service. If the leakage rate is below the minimum
allowable calibrated compression reading, and borescope examinations reveal no
abnormalities, operate the engine to normal temperatures and recheck cylinder
differential leakage.
4. For cylinders where leakage by the rings or valves is less than the minimum
allowable calibrated compression reading, further investigation in accordance with
the latest version of TCM Service Bulletin SB03-3 should be followed prior to cylinder
removal.
 
The engine is from 2001. Unsure at this point where the leak is.
The guy looking at it did have very strong opinions about continentals and even more so about this model specifically.
 
What about vapor lock? I am unfamiliar with Cirrus but is there any kind of fuel boost system intended to prevent that? I've had similar stumbles and hiccups before in the Turbo Arrow for that reason.
 
the turbo Bonanza has two electric fuel ( high and low speed) pumps....to prevent vapor lock at altitude or on the ground.
 
Checkout_my_Six said:
the turbo Bonanza has two electric fuel ( high and low speed) pumps....to prevent vapor lock at altitude or on the ground.
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As does a Turbo Arrow, although neither boost is used in normal operation, unless stumbling is encountered.
 
SixPapaCharlie said:
The engine is from 2001. Unsure at this point where the leak is.
The guy looking at it did have very strong opinions about continentals and even more so about this model specifically.
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Don't know if the model specific part is deserved but whenever I run into someone who curses the gear I always worry if it's really the gear or just a lack of understanding it. Think IT here for a second.

Also one should always ask if Continental's procedure for measuring compressions was used. It's "different". I can't imagine there's a mechanic out there who doesn't know that by now, but... Low compression numbers and a guy cursing Continentals makes my Master Caution light ding and start blinking.

I think I'd want an opinion from someone who LiKES Continentals. If you get what I'm saying. I dont ask Windows guys for opinions on Linux server architecture...
 
Sac Arrow said:
What about vapor lock? I am unfamiliar with Cirrus but is there any kind of fuel boost system intended to prevent that? I've had similar stumbles and hiccups before in the Turbo Arrow for that reason.
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Yes. If you climb high rapidly in the summer you can get vapor lock in a Cirrus. This is especially true if the plane has been sitting in the hot sun in the summer and you do a quick climb from sea level to above 11K'. I leave boost on - problem solved.
 
SixPapaCharlie said:
Plane is in annual They are "concerned about compression on 2 of the cylinders" He said they are in the 30s which I find puzzling as 3 weeks ago they said everything was in great shape.
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Both of these observations are from the same shop and mechanic?

How much time have you two put on the aircraft since you got it?

And as OCD as you are when I've seen you use the power setting function your avionics provide you, I'm surprised this is happening.
 
We have had it a year and probably put ~120 hours on it.
Same shop / Same guys. Primary guy is former Clear Star (Cirrus A&P) who stuck around DTO after clear star moved out.
 
If your mech has a borescope that can record images/video, you might ask to see what's to be seen before anything is pulled.

The reference the many Mike Busch articles on what looks correct and what your engine/cylinders are telling you based on what you're seeing.

Hopefully this is just some bit of debris between the valve and the valve seat that prevents complete closure.
 
What is the procedure for leaning a Cirrus SR22? Anyone know? Does it have a "percent power" indicator.
 
coloradobluesky said:
What is the procedure for leaning a Cirrus SR22? Anyone know? Does it have a "percent power" indicator.
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Here come the child of the magenta line comments.

There is a button... I know I know...
It is called lean assist.

You click it and start bringing the mixture back until it gives you the "You done good. Ya special snowflake" message.
Actually it says "Best economy"

 
You know how many mechanics I've seen actually do a compression check on a Continental per their compression SID? Zero.

I wouldn't go replacing cylinders because an A&P says the compression on it is "bad" unless you make for damn sure they're doing it precisely via the SID and that the SID calls for that course of action.
 
Very sporadic/random/infrequent burp, hickup, miss = air, fuel, or spark issue. Air probably not an issue. Fuel and spark could be. You need to rule out those before blaming anything on the rotating assembly. No airplane experience, 35 yrs automotive.
 
SixPapaCharlie said:
Here come the child of the magenta line comments.

There is a button... I know I know...
It is called lean assist.

You click it and start bringing the mixture back until it gives you the "You done good. Ya special snowflake" message.
Actually it says "Best economy"

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Stupid question...when you set up for that 23 mile straight-in, does it remind you to...yanno...move the mixture forward?


Reason I'm asking.... Went out and did some test flying with my old CFI a few weeks ago after I got some suspected carb ice on a previous flight... The prick leaned out the mixture at 3500' while I was vaguely doing other things (poh says full rich under 5k) and someone (PIC) didn't...yanno....perform a proper landing check and the big spinny fan thingy quit doing its thing about the time I needed to vacate the runway for an arriving regional jet.

I'm still leaning on following in your footsteps...the 20/22 are logical replacements for my chute-happy, magenta line-lusting, autopilot-dreaming self....



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Tampico Trauma said:
Stupid question...when you set up for that 23 mile straight-in, does it remind you to...yanno...move the mixture forward?


Reason I'm asking.... Went out and did some test flying with my old CFI a few weeks ago after I got some suspected carb ice on a previous flight... The prick leaned out the mixture at 3500' while I was vaguely doing other things (poh says full rich under 5k) and someone (PIC) didn't...yanno....perform a proper landing check and the big spinny fan thingy quit doing its thing about the time I needed to vacate the runway for an arriving regional jet.

I'm still leaning on following in your footsteps...the 20/22 are logical replacements for my chute-happy, magenta line-lusting, autopilot-dreaming self....



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No, temps become a part of your scan.
After I get the mixture leaned per the magic box, I hit the normalize button.

Just as you would scan your um.. Hell I don't know what real pilots scan but you want to be a Cirrus pilot so lets be real..
Just as you scan your cell phone, sporty s catalog, beer cooler in a cirrus, you add the temps to that scan.

After hitting normalize, you will see the temps on the TV as + or - some degrees. I try to keep it within 0-+15
As I descend, I add a bit of mixture to keep it in that range. It is not like the TB9 where I did full rich entering the pattern.
That will make this start to hiccup as you reduce power turning final.


Edit: @FastEddieB is going to bust me on this if I don't clarify.
I try to keep it in that range in cruise and descending. Once I am reducing power for pattern entry, I no longer care about that range. I do not do full mixture.

I don't want to confuse and insinuate I try to stay 0 - +15 to the ground. That won't work.
 
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TV? Does that thing get direct TV or Dish Network. (I kid). But thanks for answering my question... I'd just assume that it'd go full rich on descent like everything I'm used to flying (172, 175, 177, TB9)


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Tampico Trauma said:
TV? Does that thing get direct TV or Dish Network. (I kid). But thanks for answering my question... I'd just assume that it'd go full rich on descent like everything I'm used to flying (172, 175, 177, TB9)


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You can but my experience has been (in Texas at near sea level) if I go full rich, it starts to bog down a bit and scares the hell out of me somewhere around base to final. POH says mixture "as needed" If it is not asking for more fuel, I am not giving it more.
 
Not that this post will help, but why in the world, with today's tech, do humans even need to be involved in the air-fuel ratio? Plenty of fuel tech with O2 sensors that can take the human element out. Don't get me wrong, I'm a "carb guy", but for all the other tech thrown into newer planes, why still the need to manually adjust for atmospheric conditions? These are rhetorical questions, don't let me derail this thread.
 
If you lean the engine and the EGT goes DOWN, then you are at peak or lean of peak. If you lean the engine and the EGT goes UP, then you are rich of peak. You really need equalized fuel injectors (ala GAMIs) and EGT guage on all cylinders to make this work. And it is most relevant for turbo charged engines. Also, if you stay below 65% power, then you can't damage the engine by overleaning? Not sure about that one, but you do hear it said.
 
Graphic format for an SR20:

Redfin.jpg


SR22 identical, albeit with correspondingly higher fuel flow. The red area is to be avoided for continuous operation.
 
I know it's late in the thread but my SR22 with Avidyne R9 has a 4 second sampling rate. As I understand it, the system values are samples once every 4 seconds. If the stumble was only a second or so long, then it might not show in your data download. Something to think about.
 
Ours is 6 seconds.

It is in annual and the tech is saying you need to over haul 5 of the cylinders now.
1 is brand new. 2 are reporting low-ish compressions and he is saying as long as you have it off, you should replace them all.

He then says I bet when they replaced that 1 cylinder, they didn't balance it against the opposing one because I am picking up a vibration when it idles.

I asked if the cylinders are required for over haul he says no, these are all just a recommendation.
We're going to do what's required and get a 2nd opinion.

I spoke to someone I trust and he said go through the engine log and make a table showing all the compressions for every annual and look for trends. You can take compressions 10 times and get 10 results. He said the fact that the plane hasn't been flying much may be why they are so low.
 
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Are you on COPA too? There are some interesting perspectives over there on cyl overhauls. I'm with you that it is curious to have 5 cyls replaced and a prop balance. Do you have Savvy? I have them for situations just like you are describing since I'm not an A&P and some repairs could be "debugged" if you will, before they just jump to a replacement solution.
 
alindsay said:
Are you on COPA too? There are some interesting perspectives over there on cyl overhauls. I'm with you that it is curious to have 5 cyls replaced and a prop balance. Do you have Savvy? I have them for situations just like you are describing since I'm not an A&P and some repairs could be "debugged" if you will, before they just jump to a replacement solution.
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I do use Savvy. I plugged all my data into it and I can't derrive much from it.
 
I should have been clearer - Savvy also offers a plane management service. They can you give your mechanics instructions when issues are found. In a case like your Cylinders, they might suggest a borescope and some other things prior to just replacing the cylinders. It is $750 a year but might be worth it in your case. I have a good relationship with my on field A&P but after my Dec annual, I did the game spread test and they are seeing the spread increased from .02 to .07 - so they suggested I get the injectors cleaned and also adjust the RPMs to 2650 vs the 2630 I showed just after annual.

COPA.org is also a wealth of knowledge - they have a wiki area with good info and a great search feature for seeing past threads on a subject. When posting to the forum, sometimes you have to take the bad with the good when you post...but that's true anywhere on the internet.
 
http://www.savvymx.com - something to consider and probably worth checking out their web site. I used them for my prebuy in Dec 2014 and since then for maint. Again, pros and cons for using them so make sure its a fit for you.
 
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SixPapaCharlie said:
Plane is in annual They are "concerned about compression on 2 of the cylinders" He said they are in the 30s which I find puzzling as 3 weeks ago they said everything was in great shape.
We'll see... If there is an issue, I hope they can overhaul versus replace otherwise this is going to do bad things to my airplane fund.

airplanes are stupid.
Click to expand...

Now you need someone to tow an airplane into the front of your Cirrus and total the engine.
 
I don't see what the fuss is about. Fly the thing until the big spinny thing quits, pull the big red handle and have insurance replace the engine. Voila.




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Tampico Trauma said:
I don't see what the fuss is about. Fly the thing until the big spinny thing quits, pull the big red handle and have insurance replace the engine. Voila.


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You sound just like the Cirrus training program :)
 
SixPapaCharlie said:
I just signed up over there. Kicking the tires now.
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If you're using the full service of SavvyMX (where they communicate with the shop and assist in determining course of action), keep me in the loop as to how it rolls and what your thoughts are on the process and results.

I have been aware of them since I got started flying, and have considered using the service on what ever aircraft I might be sole owner on.
 
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