<hi style=afpcap>Early bomber design was based on a scaled up version of the existing biplane fighters of the day, with provision for the additional crew members needed to man the guns and act as bombardier. One of the first of the light bomber category was the Huff-Daland LB-1 which was produced in 1923. With the exception of attack type aircraft, the LB-1 was the last of the single engine bombers, as all subsequent design was based on multi engine capability. The production LB-1 followed with nine aircraft being built, with development producing the XLB-3 and 5 models for evaluation as well as the production versions designated LB-5/5A, LB-6 and LB-7. The Huff-Daland Company was reorganised prior to the XLB-3A being delivered, becoming the Keystone Aircraft Corporation. </hi>
