What can we ALL learn from this Cessna 182 engine out

mryan75 said:
What’s a “collapsed lifter”?
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Yes, it's a spring-loaded hydraulic cylinder (hydraulic lifter) that sits on top of the valve stem. It has a port that fills the lifter with oil when the (intake or exhaust) valve it's controlling is closed, then the port closes when the lifter is engaged to open the valve. This allows the lifter to adjust to the valve stem's position as the engine heats up. Collapse probably refers to the lifter not getting refilled with oil and either not opening the valve or only opening it partially.
 
denverpilot said:
I used to think that until I hit an age where I know multiple people with multiple engine outs. Of different varieties.

But I “only” know one who’s survived a mid-air.

Meaning, the former isn’t as rare as I thought, and the latter happens too, but usually kills you outright, and I know someone who got lucky.
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I worry much more about midair than an engine out. Other than certain short phases of flight, what happens after an engine out is entirely in my control. What happens after a midair, generally not so much.
 
Lindberg said:
I worry much more about midair than an engine out. Other than certain short phases of flight, what happens after an engine out is entirely in my control. What happens after a midair, generally not so much.
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.

I generally worry about 3 things while flying:

#1. Midair Collision

#2. Engine out

#3. Engine fire

I believe a little bit of fear is a good thing for some pilots. I'm much more cautious than the average pilot.
 
Sonoran said:
Yes, it's a spring-loaded hydraulic cylinder (hydraulic lifter) that sits on top of the valve stem. It has a port that fills the lifter with oil when the (intake or exhaust) valve it's controlling is closed, then the port closes when the lifter is engaged to open the valve. This allows the lifter to adjust to the valve stem's position as the engine heats up. Collapse probably refers to the lifter not getting refilled with oil and either not opening the valve or only opening it partially.
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I wouldn't think a collapsed lifter would affect the valve opening that much. Yes the engine would get noisier, but lifters I've seen collapse maybe .015" - vs a typical lift of maybe .300 inch. What's more the valve will still close fully unless the stem is badly cruded up.

I recently heard from a shirttail relative of an NTSB investigator's conclusion that was completely unjustified by the evidence.
 
I haven't researched 182 collapsed lifters, but I know the AD research paperwork for my plane says my engine doesn't have the AD affected lifters. I might research that later.

Collapsed lifter can cause low RPM and high stress on valve train parts. Imagine a solid lifter with too much lash. Too much clearance between cam, lifter, pushrods, rockers, and valve stem tip. Stuff will "slam" together on valve opening and then possibly "slam" closed if collapsed enough. My usually disclaimer on POA engine threads is that I am not an A&P, but broke and tuned drag race engines as a hobby.
 
nrpetersen said:
I wouldn't think a collapsed lifter would affect the valve opening that much. Yes the engine would get noisier, but lifters I've seen collapse maybe .015" - vs a typical lift of maybe .300 inch. What's more the valve will still close fully unless the stem is badly cruded up.

I recently heard from a shirttail relative of an NTSB investigator's conclusion that was completely unjustified by the evidence.
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I don't recall what Continental's clearance specs for lifters are, but the Lycoming specs are 0.028-0.080" of clearance when collapsed. I agree with your opinion, I don't feel that a collapsed lifter would cause a valve not to open, it just won't open as much.

I didn't go back and re-read the thread posted about the incident that was linked here, but I thought there were some ignition problems with this engine that was determined to have caused the problem?
 
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