Voyager does not hold the endurance record for time spent aloft. Their trip was 9 days, 3 minutes, and 44 seconds. Design range was 22,778 nm. Eat your hearts out, Boeing and Airbus!
Timz is right. The Cessna 172 holds the record and was flown by Robert Timm and John Cook. They took off December 4, 1958, and landed February 7, 1959. They were aloft for 64 days, 19 hours, 22 minutes, and 5 seconds.
They covered 150,000 miles in that time. They refueled from a speeding car on the runway.
The Grizzly had excellent short takeoff and landing performance. Just because it didn't go into production doesn't mean it was a failure. A lot of his designs were one-off designs that were genuinely experimental. He pretty much single-handedly started the high performance experimental aircraft movement that now sees aircraft like the Lancair IV
-P. Not to mention basically inventing the glass-backwards foambuilt. Rutan closed his Rutan Aircraft Factory and got out of the light airplane business because of legal liability issues.
The Grizzly is that big plane in the center