On this day in 1911, the U.S. Army Signal Corps accepted its second airplane, the Curtiss Model D Type IV, at Fort Sam Houston, Texas. Designated Signal Corps Airplane No. 2, it followed the Wright Military Flyer into service and used ailerons instead of the Wrights’ wing warping system for lateral control.

Aircraft: Curtiss Model D Type IV

• Length: 29 ft 3 in (8.9 m)
• Wingspan: 38 ft 3 in (11.7 m)
• Height: 7 ft 10 in (2.4 m)
• Engine: Curtiss Model B-8, 90 degree V-8, 40 hp at 1,800 rpm
• Top speed: 60 mph (96.6 km/h)
• Endurance: 2.5 hours