The Curtiss Carrier Pigeon was an American mail plane of the 1920s. A single-engined biplane designed and built to replace World War I surplus aircraft such as the DH-4, the Carrier Pigeon was one of the first aircraft designed specifically for U.S. Airmail service. Design In 1925 the U.S. Postal Service felt they had excellent operational service with converted Airco D.H.4 biplanes. The eight-year-old designs were considered antiquated by this time, however, and a modern purpose-built machine was desired. While most manufacturers started to build new generation passenger aircraft with mail cargo capability, the Curtiss Carrier Pigeon was the first clean-sheet design specifically made for U.S. air-mail service. The aircraft was intended to be sold directly to the Postal Service, but new legislation that opened up outside contracts brought on a slew of competing models. The Carrier Pigeon was drawn up to meet or exceed the original postal specifications. Strength, serviceability, and ease of maintenance were the three core design criteria. It was intended to provide service on the nighttime runs between Chicago and New York, with only one stop. The plane was built to take advantage of the powerful and plentiful 400 hp Liberty L-12 engine to meet Postal specifications. Up to 40,000 airmail letters could be carried in the 1,000 lb capacity cargo hold. The fuselage was a welded steel tube frame covered in fabric. The upper and lower wings were interchangeable and used solid, unspliced spruce spars. The rudder, ailerons, and elevators were also interchangeable, which reduced spares counts. The hinges used heavy replaceable bronze pins to reduce wear. The watertight cargo hold was at the center of gravity so the aircraft could accommodate a range of loads without affecting the balance. The landing gear used rubber doughnut suspension. The fuel tank could be jettisoned in case of an emergency. A seven quart fire extinguisher was plumbed to the engine compartment for suppression of inflight fires. The pilot could choose between wheel or stick control based on his preference. Operational history A prototype Curtiss Carrier Pigeon flown by Charles S. (Casey) Jones placed 7th in the 1925 Edsel B. Ford Reliability Tour. Out of 17 starters, 11 aircraft including the Carrier Pigeon completed with a perfect score, netting a $350 prize. Henry Ford waited at the finish line to greet the winners of the 1,900 mile endurance test. The Carrier Pigeon was used by National Air Transport