Stout 3-AT

The Stout 3-AT trimotor was the first all-metal trimotor built in America. The poorly performing tri-motor led to an updated design which became the popular Ford Tri-Motor.

Development
As a friend of the Ford family, Richard Evelyn Byrd visited Dearborn in 1925 with the polar exploration aircraft. The all-wood Fokker F.VIIA-3m named the "Josephine Ford" and owned by Henry Ford's son Edsel (and named for Edsel's daughter). The airplane was received as a gift from his father after being placed first in the 1925 Ford Reliability Tour, and lent to Richard E Byrd for his trip to the North Pole, which was sponsored by Ford. This airplane was the prototype for the Fokker F-VIIA-3m and was based at Ford Airfield (now the Ford Test Track in Dearborn, Michigan) and Stout's factory location. Several measurements and photos were taken during its stay. Shortly afterward, the model 3-AT trimotor was produced using an all-metal construction technique. There are many similarities between the designs that caused controversy. There are also enough differences in technologies between the aircraft that the 3-AT can be seen as a unique design as well.

Design
The 3AT trimotor had a blunt nose-mounted radial engine, and two outboard engines nestled deep in the wings. The aircraft had a large passenger and cargo compartment with semi-circular windows and a large forward-looking glassed-in window section. The pilot sat in an open cockpit mounted high on the nose of the aircraft. The original design featured three Liberty engines, but they were quickly abandoned due to weight issues.

Operational history
The 3-AT was underpowered for its size. Test pilot Rudy "Shorty" Shroeder could barely circle the field and refused to take off in the plane again. He advised Ford, "Forget the plane." The Model 3-AT trimotor was heavily promoted by Henry Ford as the airplane of the future. Test flights proved otherwise, with the underpowered aircraft barely able to maintain altitude. After witnessing the tests, Henry Ford left outraged. Ford told Mayo, "This plane is a mechanical monstrosity and an aerodynamic absurdity. From now on keep Stout out of the design room." Shortly afterward Ford reassigned Stout away from engineering.

On January 16, 1926 a fire destroyed the Stout factory and all aircraft in it, including several 2-AT's and the 3-AT Prototype. In a 1951 interview, engineer Harold Hicks said that the fire and a fresh start were the best thing that happened to Ford's aviation venture. The 3-AT was impractical with its uncowled engines mounted in the wing roots disturbing the airflow over the wing, giving it an 80 mph takeoff and landing speed.

Tom Towle was placed in charge of engineering, and hired MIT graduate Otto C. Koppen, John Lee, and James Smith McDonnell (co-founder of what is now McDonnell Douglas). Together they refined the 3-AT into what is now recognizable as the "Tin Goose", the Ford Trimotor.

Variants

 * Ford 4AT The basic 3AT design with the main engines placed in underwing, strut-mounted nacelles, and cockpit moved internally.