Inner tubes need inspections too.
Four years from new, and hardly ever needing top up air one main u/c tyre looked a fraction soft, so it was pumped up to the usual 18 psi & thought no more of it. Two weeks later & it was discovered almost flat, luckily the Rans was safe inside in the hangar.
Decided it must be a sharp hedge thorn, but couldn't find evidence from the tyre's outside. To do a proper job the wheel was removed & the plastic rims parted to feel round inside the tyre. Nothing doing and tube looked whole ?
That's till it was re-inflated, when a line of perishing or cracking was discovered. It was right along the line where the wheel halves join yet not a faulty manufacturing seam. CFM Shadows with original Nylon rims apparently had similar issues of flexing & chafing the tubes, resolved by their using Ali rim halves. As inserting tape or a band underneath isn't feasible, expect your tubes to suffer similar deterioration. If you don't want to be caught out & damage your a/c on landing, put this on your inspection list.
The solution that I came up with was to cut a strip from the bottom of the old inner tube and remove the old valve leaving a hole. This is easy to put in place with the valve stem of the new tube protruding though the hole left by the old one. It's worked well for me for a good number of years and saves that nasty sinking feeling when opening the hangar on a nice summer's evening
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