Might be just hard to find good help these days but based on my own IT experience I expect you're right about the expired security certificate. It's just an admin matter - i.e. money to renew registration.
Even so, I wrote to them probably more than a year ago to point out that the information on their Grumman Goose page was backwards - they listed its "cruise" speed as 191 mph but its "top speed" as only 130 mph. That didn't make any sense, so I wrote - and they replied, acknowledging the mistake, but here it is something like a year or more later and they STILL haven't made the correction on the Web site.
https://yanksair.com/Products/175/98/Grumman-G-21A-Goose/Also noticed that the Web page for their "
G-64 /
UH-16" Albatross contains an error or two as well - because it is actually a long-wing variant (i.e. no longer a design no. G-64 aircraft which had a short wing.) And of course "UH-16" is incorrectly transposed from "HU-16". According to my notes,
N7024S is in fact an ex-USAF
HU-16B, USAF serial no.
51- 7195 (Grumman OEM serial no.
G-258) which was converted from a short-wing design no. G-64 aircraft to a long-wing
design no. (not "model") G-111 aircraft as Project no.
85B (i.e. the 86th such long-wing conversion for the USAF out of 89; nos. 00B through 88B)
https://yanksair.com/Products/71/110/Grumman-G-64-Albatross-UH-16/