There is no set time for changing seat belts. An inspection
of seat belts includes checking for broken stitching,
missing TSO tags and snags. If the belts have been
in the sun for several years the belts start to deteriorate,
shrink and become hard. The hardened condition will
deteriorate the stretching ability of the webbing and
could create an unasafe condition. According to FAR
43 appendix D seat belts are inspected for poor condition
and apparent defects.
Patti Browne