But it didn't start with this life limit, it's an extension.

When composite construction methods were first introduced, the design
standards were made to an ultimate life of 18000 hours, given so many
unknown about how composite gliders would hold together or degrade due to UV
exposure. Service life was calculated to be 1/6 of this, or 3000 hours,
though there were variations on this. Service life extensions were then
granted following inspection schedules. Same applies to some metal gliders
as well. Most, if not all gliders, have had life extensions. Anyone know
of a composite airframe design that has been grounded permanently due to
reaching ultimate life limits in the absence of balsa rot or something else?
Metal fittings may need periodic replacement.

When a glider has new innovations in construction, lay-up, and design,
having a conservative initial service life may just be reflection of policy.
Several Polish designs have more conservative initial service lives than the
German gliders, but I don't know if that's driven by a design philosophy, a
national policy, or something else. They also seem to continue in service
following reaching the initial service limits.

Frank Whiteley

"Waduino" wrote in message
...
Different plane of course, but just for comparison the ASK-21 is now
approved for 18,000 hours. That's right. 15 times longer. Big difference.
Wad.


"BTIZ" wrote in message
newsihId.4917$ry.3026@fed1read05...
only 1200 hours??
and I was thinking about getting one... not at that price..
$55K used, 1000 hours (already has 200), that's $55 an hour being used
up
plus costs

BT

wrote in message
ups.com...
For crying out loud, it is hard to argue with a Brit. But in this case
you have a valid point and I applaud your comments. I don't understand
that the manufacturers of Diana don't see the facts. Only few gliders
sold, limited lifespan of 1200 hours, limited support, etc. The
sailplane obviously has excellent performance. I don't think that
anybody is questioning that. I wish the manufacturer and designer of
the sailplane best of luck, but I also think they need to hire a market
analyst and good marketing company, familiar with global market in
order to succeed. The performance numbers will not do the sales alone.