In article ,
Andreas Maurer wrote:

On the other hand - these days gliders don't wear out anymore. If
necessary, a re-finishing (we are doing this by ourselves) is cheap
(but lots of work) and then the glider is as new again, so it's likely
that gliders will be kept for a longer time (15-17 years at least) in
the future.

You sound positively rich.

Our club owns six gliders: three two seaters, and three single seaters
(all glass). The two PW-5's are only eight years old, but everything
else (2 x Twin Astir, 1 x Janus, 1 x Std Libelle) is 25 or more years
old, though all but the Libelle have been purchased in the last ten
years.

In fact the vast majority of the privately owned gliders (which far
outnumber the club ones) are also more than the 15-17 years old you
mention.

-- Bruce