I had the ifr/static certification done last summer... Same deal,
static line would not hold pressure.... He found a static line that was
completely disconnected behind the panel... The plane had been flown in
hard IFR in the meanwhile... Luckily, the inflight air pressure inside
the cabin is only about 30 feet different than the static ports...
Looks to me like it was the mechanic at the 100 hour who had changed
the vacuum filter that did the deed... I will remind him about that
next month when the annual is due...

denny and Fat Albert the Apache