We have an glider that has gone through the same process.
The original Airworthy Cert was for one year and then it expired, this was
in 1980-1981.
The owner then applied for a new Cert and it has no expiration but it does
require annual "condition inspections" per the glider factory published
maintenance manual and AC43 Apx D.

Just based on what you have provided for information. I would say that your
glider has been flying since 5/5/1984 illegally. I am surprised that all of
the previous AIs signed off the condition inspection without a valid
Airworthy Certification.

Go to www.faa.gov and search for your aircraft records, you can get a copy
of everything the FAA has on file on a CD for about $10 and it takes about
two weeks to process. You can order it on line. I have done this for all of
our aircraft and for aircraft we were looking to purchase but then did not
because we found paperwork or other issues such as an unclean title. A loan
or lien against the aircraft that was never properly released.

BT

"PS" wrote in message
...
I just purchased a glider that has a Special Airworthiness Cert.,
Experimental Category, Exhibition and Racing. The "Date of Issuance"
was 5/6/1983, as was the Operating Limitations and log entry. To the
right of the Issuance date on the certificate is the "Expiry" which
shows one year later as 5/5/1984. The operating limitations makes no
mention of an expiration, in fact it has the paragraph stating that
"no person shall operate...unless condition inspections are done in
the preceding 12 months" (which would be for the second and future
years), and it mentions condition inspections (plural) are to be
recorded. The entry in the log by the same FAA Rep. makes no mention
of an expiration.

This would have me think that the intent of the FAA representative was
to make the certificate of unlimited duration as I would expect. The
FAA database also shows no problems that I can tell, such as an
expired airworthiness certificate. Is this typical to have an "Expiry"
date on the cert. or do I have an issue? I hate to lose my loose
operating limitations by having to apply again. Can anyone explain?