
...by an inclined PLANE
wrapped helically around an axis?
The Big Bang Theory Season 4, Episode 5

...was watching over the PLANE.
The Big Bang Theory Season 8, Episode 23

That nut job was telling everybody
on the PLANE he's an astronaut.
The Big Bang Theory Season 6, Episode 4

if you're getting
on that PLANE
The Big Bang Theory Season 12, Episode 22

and the shoes,
the PLANE tickets.
The Big Bang Theory Season 12, Episode 23