1957 - project
VTOL aircraft project with four foldable ducted fans. Not built.
David A. Brown "The Bell Helicopter Textron Story", 1995
Technical data for Bell D-230
Engine: 1 x Continental T51-T-3 turbine rated 375hp, overall width: 5.6m, overall length: 4.85m, overall length with ducts folded: 3.05m, rotor diameter: 2.0m, gross weight: 1100kg, empty weight: 550kg, useful load: 550kg