What year did the Pogo Plane first appear in the Fantastic Four?

Answer 1

I'd say the very first issue---when though they don't name it--but you see it speeding away from Monster Island( even though it looks VERY different!)

issue #3 was the first fan-tas-ticar!

The more rocket -like pogo plane was used around issue 45 or so when searching for the Inhumans!

great question---had to think awhile!

Answer 2

Fantastic Four, vol 1 #3
Cover Date: March 1962