It is not often I see such a display of collective ignorance from the members of this forum
The engineers correctly identified that the aluminium chips resulted from damage to a piston pin plugs, it is most likely that the piston pin damage resulted from a ridge in the bore resulting from corrosion Most likely resulting from under use.
The consequences of ignoring this evidence of internal damage would be to allow the piston pin plug to break up and the wrist pin to migrate into contact with the bore. The damage resulting from the high carbon steel wrist pin coming into contact with the nitride steel bore would be to fill the engine with very abrasive steel debris destroying the engine from the inside
The owner far from being a mug who is being ripped off by cowboys, is a man who has wisely put his trust in careful technicians who had the experience and knowledge to pick up the problem before it became a major and very expensive issue.
I have no dog in this fight and I am sorry if my opinion offends some of you but after forty- five years of holding a maintenance license and having seen piston pin plug problems on a number of occasions I am just calling this one as I see it.
Or as the borescope would have seen it.
Ah the good and the bad of internet (or very public in anyway) exposure…sometimes we tend to underestimate that power.
A lot of maintenance actions on small aircraft can be complex. When you are experienced they may be taken for granted, but there are a lot of details involved. Furthermore, such experience may bring different approaches to the same problem and may involve different details for the same task depending on who is doing it.
That is why replacing the oil filter on an A320 is a 10-pager in the AMM whereas for a Cessna it is a two-liner in the service manual: they want standardized approaches for large aircraft. I , for one, don’t think that approach would benefit GA.
In maintenance we tend to treat OEM advise like the Gospel, and an A320 Gospel for your PA-28 will do more harm than good.
It is thus easy to find or consider mistakes the different approaches to GA maintenance if you watch a maintenance task closely. Well, in this case the elephant in the room of indiscriminate cyl removal was too obvious.
However, what is the single biggest problem challenge in light GA ownership? (other than dealing with UK politics, Greek airport fees, French PPR’s, unresponsive Spanish airports, indecyphrable Italian fees, nonsensical German Flugleiters …)
Yes, I agree with you: maintenance.
And what is the single biggest issue with light aircraft maintenance? The scarcity of good maintenance technicians. Lots of stories in this forum:
Those who know a good one tend to keep it to themselves. They tend to be overloaded, expensive, unresponsive…
It is easy to be critical of maintenance organizations and technicians, but not so easy to be one while providing a good service, keeping customers happy and making a decent living out of it. The perfect storm thrown their way by the advent of EASA , the frequent too-cost-focused owners, and the attraction of technicians to the airline world does not help.
I for one think we need to do better, in GA in general, but in this forum in particular, in looking after the maintenance community.
All is well that ends well: in my view this particular maintenance crew did a good job of finding the culprit and making the aircraft safe. Would I have chosen that path? Hell no. But are we helping the case by throwing flak at them bearing in mind their will to be exposed in such a way?
Yes we must educate the maintenance community into being less keen to remove cylinders, but we can also do it in a better way. We cannot expect maintenance to take the flak in the usual way we pilots throw it at one another…
#lookafterGAmaintenance
I agree Antonio. But ….. the second golden rule of aviation is to evaluate and respond accordingly. Panic is never likely to help, in the air or on the ground. Making a big media splash from a questionable set of decisions is likely to attract comment.
My wonderful Spaniel Arthur woke up the other morning in tremendous pain having prolapsed a disk. We didn’t know that at the time. Could have been meningitis, a slipper disk, poison; a long list. I could hardly move him without him crying out in pain. Here is an animal we love dearly and for whom we have complete responsibility. Even with that very real sense of urgency and pressure, there was a process, without which poor decisions would have been made. As the vet moved through one scenario to another, time became more of the essence, but the path had to be followed.
He’s fine now. No unnecessary operations or drug cocktails, no lasting side effects. He got an MRI, the precise treatment of steroids in the exactly the right spot, and four weeks of bed rest later, easily the hardest part, he’s bouncing around like the mad thing he is.
So I’ve laboured my point.
My own irritation stems from a relatively low time pilot putting out videos that, if I may, seeking an air of authority that has not been earned. Is this really about maintenance or just publicity? Is it usefully informative, or is it publicly?Makes for a whole lot better story to add some drama.
Not better aviation.
*PIG
The problem with the root of this problem is the bore ridges that result from corrosion are usually at the BDC position of the compression rings, the corrosion having been started by electrolytic action between the steel cylinder and aluminium piston.
The result of this is the piston obstructs and view from a bore scope from the top end and almost if not impossible from inside the crankcase ( depending on the engine ).
Given these difficulties even if the first cylinder you remove has evidence of piston pin plug problems you can’t rule out the possibility of the same problems with another cylinder.
The removal of one cylinder requires a lot of the exhaust, inlet and baffles to be removed so it is far more cost effective to remove all the cylinders at this point and rule out further trouble rather than repeating the process when you find more aluminium chips in the oil filter at the next check.
Any particular reason why it starts BDC? Just thinking about the random position pistons end up in on shutdown.
Ok then Vic I guess I will just have to live with the fact the game is up on my program of ripping off customers.
So at my advanced age I shall retire and watch with detached interest as the enlightened amongst the forum continue ignoring what their engines are trying to them.
A_and_C
I very much appreciate your comments and would of been far better off if Ihad listened to you.
