Born in Quincy, Illinois, Longlet learned to fly in 1932, attended mechanics schools in St. Paul and earned his A & P license. He worked briefly for Mid-Continent Airlines, the Mod Center at Holman Field during World War II, and at Patterson Dental before moving to Minnesota Mining and Manufacturing (3M) to co-create the flight department. He served as pilot, maintenance test pilot and maintenance supervisor there.
During his 30 years with 3M, Longlet served as a consultant to nearly every corporate flight department around the country. His reputation extended internationally.