Aero A.24
The Aero A.24 was a twin-engined biplane bomber aircraft of the 1920s. Flight tests showed it to be severely underpowered, making it useless as a combat aircraft. Only a single prototype was built.
Aero proposed a variant designated the A.27 that was to have overcome the A.24's shortcomings by re-engining the design with Bristol Jupiters, but the Czech Air Force was not interested in pursuing this option, and all development ceased.