Wiktionary
wing walking
n. stunt performed at airshows, particularly in the interwar years, where a person climbed through the struts of a biplane, or flew strapped in a frame on top of the aircraft.
Wikipedia
Wing walking
Starting in airshows and barnstorming during the 1920s, wing walking is the act of moving on the wings of an airplane during flight.
Usage examples of "wing walking".
They had stunt displays, and wing walking, and a parachute descent, and a pretty girl flying a glider.
The Moth was steady as a table and was Joel's and my favorite for wing walking and stepping off from one plane onto another.