In 1920, Weldon and Wilber Larrabee opened the first aviation business (now called an FBO), the Security Aircraft Company, on the site of the Minneapolis Speedway near Fort Snelling. The racetrack had gone defunct in 1916 after only a single season of auto racing in 1915. The brothers built a hangar using the concrete racetrack as its floor. They commenced to cater to visiting flyers, providing minor maintenance, shelter, aircraft sales, and sight-seeing. The racetrack, with its two-mile white concrete circle became a beacon to fliers coming to the cities. Along the way, Weldon and Wilber, seeking a reason to draw people to the business, created a thrill show troupe, alternately known as the Dispatch Flying Circus, sponsored by the St. Paul Dispatch newspaper, or the Daily News Flying Circus, sponsored by Minneapolis Daily News. Such prominent local pilots as Walter Bullock, Speed Holman, Al Backstone, Guy Carroll, Jack Malone and Ed Ballough performed aerial stunts and wing walking and parachute jumps. Weldon’s brother, Wilber, often billed as the “Flying Squirrel,” clowned around between wing struts. The flying circus would later be sought by county fairs and other outdoor gatherings.
In 1923, the speedway was dedicated as Wolds-Chamberlain Field, a full-fledged airport, and the brothers sold the business operation. Weldon, had created an orchestra which played often in the Twin Cities. He moved to California where he wrote and published music and also created greeting cards.