Adam A700: First Of The Microjets? The last rush of specific aircraft types came in the late 1970s when Piper, Beech and Grumman-American all fielded light-light twins—the Seminole, Duchess and Cougar, respectively. At the time, general-aviation manufacturers were turning out 15,000-plus airplanes a year, and pilots were training at a record rate. Practically everyone was predicting there would be a viable step-up market for new aviators transitioning to twins in search of the peak of the pyramid—an airline job. To access this content, you must purchase Plane and Pilot Membership.