The Orenco B was a prototype American fighter aircraft of World War I.
It was a single-engine, single-seat biplane that flew in 1918.
Although it demonstrated good performance, only four aircraft were built.
The Ordnance Engineering Corporation of Baldwin, Long Island, designed and built its first aircraft, the Type A, a two-seat trainer in 1917, although no production followed.
To design its second aircraft, a single-seat fighter, it acquired the services of Frenchman Etienne Dormoy, a member of the French Aeronautical Mission to the United States, who had previously worked for SPAD.
The design, the Type B, was a single-engined tractor biplane of wooden construction.
It was powered by a single 160 hp (120 kW) Gnome Monosoupape 9N rotary engine and had two-bay wings.
Planned armament was three Marlin machine guns, one under the upper wing and two under the lower wings.
The first prototype made its maiden flight in early 1918.
It demonstrated good performance, reaching a speed of 135 mph (117 kn; 217 km/h), and four aircraft were ordered by the Aviation Section, U.S. Signal Corps, along with five of the closely related Type C fighter trainer, the first being delivered in March 1918.
Despite this, the type was not adopted further, as the 160 hp Gnome did not go into production in the United States, and the US Army decided to build European fighters under license instead.