All Aero

The XLB-1 three-seat, single-engine light bomber was tested in 1923.
The single engined configuration, mounting an 800 hp Packard, proved unsuitable and the basic LB 1 airframe was redesigned by Keystone in 1927 as the twin engined XLB-3A, with two 410 hp Pratt & Whitney R 1340-1 Wasp nine cylinder radials mounted midway between the equal span wings. The complement was increased from three to five (pilot, copilot, bombardier, and front and rear gunners) and the bombardier was located more conventionally in the nose, instead of amidships as in the LB 1.
In 1924 Huff-Daland was reorganized as Keystone Aircraft Corporation and the production bomber aircraft was known by this latter company name.