I fleshed out more of the story -

[Brother Buzz]

Lefty Gomez and Warren Russell, Kurt's grandfather, was the connection.

Lefty Gomez was totally a flying nut, but the Yankees prohibited him from flying, so he flew with Warren Russell on the quiet. And it looks like it was not a mere 'floatplane' business; during this period, Lefty Gomez earned his pilot license.

Russell's grandfather was an aerobatic pilot with over 45,000 hours who flew "well into his sixties" and had also spent time as a senior check captain for TWA and a test pilot for Howard Hughes. However, Russell himself never took up the opportunity to fly with his grandfather – a decision he came to regret as it was not until 1988 when he himself finally caught the flying bug and began his pilot training under the watchful eye of his grandfather.

It's fair to say Lefty Gomez became a lifelong friend with the Russell family, and so it was fitting and really special when Lefty Gomez made his cameo appearance in the film to present Bing some sort of baseball award in Portland.