Think of the old-timey oilers - the ones with the long, narrow spout, with
the reservoir at the bottom. The bottom of that reservoir was convex-shaped.
Another example would be on the top of a jelly jar - you know, the ones that
once the seal is broken, the middle of the lid pops up a tiny bit.

If you press on either the oil can or the jelly jar lid, it will go in an
out a bit, and spring back to its original form. So, if you have a panel on
the plane that you can press, and it springs in and out, that's "oil
canning."

By itself, it's not bad, and (no A&P here...) is not an airworthy issue. IF
however, a formerly straight and tight panel starts to oilcan, you might
have it checked to see if you overstressed a wing or tail that would cause
one of the spars or ribs to bend a bit, creating "looser" metal in that area
of the panel, which could then cause the oil canning effect.


"MRQB" wrote in message
...
What is Oil Canning? How is It Spotted? What Problems Dose It Cause? Dose
It
Affect Airworthiness? If So How Is It Resolved or Fixed?