Grover C. Loening built his first airplane in 1918, the diminutive single seat M-2 Kitten monoplane, soon refined into the more powerful 2-seat M-8 that was accepted and purchased by the Army Air Corps. However, due to the resistance towards monoplanes he reverted to a biplane configuration in creating his most successful design six years later, the OL amphibian. The Loening OL and it’s derivatives would soldier on with the Army, Navy, Marine Corps and Coast Guard for another decade.