You’re getting a new case to get the traditional two mags and dump the single dual mag system you currently have? Unrelated to the set screw propeller problem.
Neal has it. Sticking with the g5d. Going to a g5 would require sourcing another crank, accessory case, and a bunch of gears. Maybe the cam, too, id have to look. Decided to pursue speed and cost rather than the upgrade. I know all those parts are good on my engine.
There's some scarring in the bore where the shaft lives. Since the shaft isn't supposed to spin, it'd likely be fine, but I'd hate to get it apart and find it's out of spec and has to be worked over, then have to wait for that. Also, the threads in the plug hole are flattened. Again, probably okay, but but one less thing to worry about, as is the set screw hole, which is clearly deformed to some extent. Finally, there's that niggling doubt in the back of mind that Chris is right and there's something wrong with the case....
With his current and future needs, probably should just get something more “future proof”.Judging by your Avatar, seems like that works for kids as well!
The only harmonic dampening system I'm aware of is the crankshaft counterweight system. What more can one do beyond replacing the bushings as Lyco requires whenever the engine is opened? I've been considering sending the rotating assembly out to be balanced, although I'm not sure how much this will achieve as it was balanced by the original builder and none of the parts have been changed.
Been thinking about that. I'm going through the service letter list myself right now, and I'm beginning to understand how easy it would be to miss one. That said, the Lycoming overhaul manual still refers to the "spring pin", which no longer exists, so you'd think that'd cause someone following the manual to go looking. When I realized that his charge was 11K, not 20 (that included the R&R & prop), I decided it wasn't worth pursuing, but I tend to agree with your assessment. It seems like the whole point of sending the engine work out is to get it to an expert who wouldn't miss stuff like this. I am looking forward to opening the case and getting a good look at the screw area, and particularly seeing if there's any loctite in there.
Yeah, in all honesty I can't afford an airplane big enough to cart everyone comfortably. A twin commander, a 414, a Navajo. The oldest is 16, so I'm looking forward to kicking her butt out of the house, which frees up a seat.
She's old enough to solo. Just get another plane. What's the difference? Still 2 engines to maintain.
you haven't seen her drive...
I believe the quote was “We don’t do SI’s unless specifically requested but do the AD required.” So I don’t find where he designed his own repair method or deviated from the rules. Perhaps he used a different OEM reference for the work? But its tough to make a complete assessment without the shop here to give their side. Regardless, I think the OPs current plan is one that I would have also recommended based on what has been posted so far.
Help me out here
Depends. First some context. Each AD is an actually a new regulation that revises Part 39 and everyone must comply them. A SAIB is for informative purposes only and has the least priority even below ACs, SBs, and SLs. OEM documents are optional unless required by a regulation. For example, if an SB is called for in an AD, Part 39.xxxxx makes the SB mandatory, or if the OEM issues an Airworthiness Limitations Section, then 43.16 and 91.403 make the ALS mandatory for everyone.
It is strictly up to the owner whether they want to comply with OEM recommendations and bulletins. And you’ll find a number of Part 91 private owners tend to lean toward not following those OEM items mainly due to cost and no real bang-for-buck to their operation.
Anything is repairable, and more appropriately economically viable for repair, if you ensure the cost of its replacement is even higher.At least our old airplane engines were designed and built to be repairable.
Maybe…but if you don’t make parts or manuals available, it makes the cost of repair pretty high.
I’ve always found this to be an interesting concept: don’t perform maintenance due to the chance the mechanic will FU. Its been my experience that if an owner is proactive, using qualified mechanics, they will always end up way ahead of all MIF concerns.
Depends on the bulletin. I’ve found that in most cases where the bulletin has you looking for a certain condition, you’ll end up finding that condition or something else similar. What I think is more important is to at least address the topic of bulletin vs dive in head first just because.
Depends on what the maintenance request is. For example, if an overhaul then most OEMs require all applicable bulletins to be complied with in order to sign off an OH. However, with IRAN work there can be too many variables to give a specific answer. Any guess how many bulletins could be affected by splitting a case? As to the Loctite question, what if the shop used an alternate OEM document that covered the work performed, but it did not include the use of Loctite as in the other document?
My Bad! - I did not fully understand the governor location...but on review, the camshaft is actually driven by the back of the engine so torsional vibration at the rear could just be compounded by the camshaft windup to make a still worse torsional vibration environment at the governor. Much depends on Lycoming doing their sums correctly during the design, and seems to this MechEngr that they were getting painted into a corner simply with the requirements.
Mechanic errors are one thing. But not scheduling a SB due to the “opportunity” for mechanic error is something completely different which is the interesting part. Or maybe I’m just not following your point? Perhaps give a specific example of where you would not have an SB performed due the chance of a mechanic error?
Whatever brain games you do...please shareFWIW - I have engineered spinning torsional vibration test systems for car drivelines, but my initial experience (I'm 86 now) was using the same technique to control sway in high rise buildings. The principles are the same.
You'll find the higher risk is usually in not performing the mx action vs how that action is performed by the mechanic. Mechanic error is not caused by the task, but by the improper performance of the task. And those 2 points are not directly connected. And since a number of SBs, SLs, etc are usually preventative in nature, delaying the task compliance is what causes a higher "failure" rate.
I read it as there was a specific written repair method documented for this problem, and that the mechanic explicitly chose to not follow that procedure. I absolutely could have misunderstood it. If he invented his own method to effectively re-design a part on a certified aircraft, I'll stand by recommendation, though. AFAIK, modifying part of the power system isn't something to be taken lightly.
That's a great question. Yes, I do. Looking back, I see my iron number is above "universal averages", but no so much that I or the analyst ever paid attention to it. Makes me question the value of oil analysis.
As I understand it, not directly, but there is an oil supply for the gears & their bushings. I believe the shaft intersects an oil galley because when the first one popped out, oil pressure dropped to almost nothing and it pumped the oil out through the hole within a minute or so. There should be more than enough oil moving around there to flush the metal into the sump. Never found any ferrous chunks in the filter either.
The most recent is from March of this year. The set screw and shaft didn't lose much metal, but that cap.... It's steel. The shaft removed at least .080 of material based on the height of the last remaining thread. I'm guessing it was more than that, but I don't have a new cap to compare it to.
Send the current oil off to Blackstone for oil analysis and see what comes up. I'm wondering if because your engine has had unit averages for Iron near 46-48 at points in the past, it doesn't raise alarms despite being above universal averages. Also not sure if their universal averages are specific to your engine model or all piston-GA models. It would be interesting to know what data set it uses to show the universal averages.
) And POA, of course. Can't forget POA.