Here's a sketch for last year's art auction at the San Diego ComicCon International. I was inspired by the Ultimates version of Captain America from issue 1, but couldn't find ref (!), so I drew it from memory.The Star-Spangled Soldier is standing on the wing of a Ju 87 G Stuka he's just busted the crap out of, for all you aviation fans.
Captan America copyright Marvel Entertainment. Artwork copyright Charles H. Wojtkiewicz