Friday, February 12, 2010

When rings should be replaced on aircraft cylinders?

 I have a question on when rings should be replaced on aircraft cylinders? When I worked at --------- in Cameron park for ----- --------- he had the policy that any time a cylinder was removed the cylinder was honed and the rings were replaced automatically regardless of time or condition. This seemed like a sound policy. I have seen many instances where cylinders have been removed and the rings were not replaced nor the cylinder honed. Do you have any guidance on this subject?

In my opinion if the cylinders are removed and no work done on them (such as removing the cylinders to gain access to the lower end) then they need not be honed or re-ringed. Our shop did this many times on propeller strike inspections for example. In this case we would slide the piston out far enough to remove the piston pin. This was done when the conditions warranted: engine was within manufacturers recommended TBO for hours and years; engine compression and oil consumption was normal; no outward signs that something was amiss with the cylinders. 

It is sound policy to replace the rings anytime you hone the cylinder. 

No comments:

Post a Comment