Dorand's most successful pre-War design was the 1913 armored biplane: at least 6 were built with the designation Do 1 on the rudder. The lower wing was slightly shorter and set forward of the upper wing, "to improve the lowering of pressure on its upper surface." The long covered fuselage had 2 cockpits forward, pilot in the rear. The biplane tail unit had 2 elevators and was fitted ahead of a large rudder. On one of the Do Is, Labouchere flew 18,000 km in 1913; early in 1914, a group of 6 led by Captain Leclerc flew 1,400 km in 6 stages: Villacoublay to Reims to Verdun to Chalons to Villacoublay to Dijon, and back to Villacoublay again, suffering only 2 "incidents."
   The Do 1 was the forerunner of the 1916 Renault AR Is and AR2s; very precise data were made available by Dorand.
  
   (Span: (upper) 12 m; length: 12 m; wing area: 50 sqm; empty weight without armor: 625 kg; weight of armor plates: 90 kg; gross weight: 1000 kg;; endurance: 4 hr; max speed: 108 kmh at sea-level, 100 kmh at 3000'; slowest speed: 55 kmh; ceiling: 8,400 m; climb to 4,500 m: 16 min; take-off: 90 m; land: 95 m; 10-cylinder 86.5 hp radial Anzani)