|
|
The Douglas O-7 was a version of the Douglas O-2 observation aircraft that was powered by a Packard engine in place of the original Liberty engine.
The O-2 was an equal span biplane, powered by the wartime Liberty engine, and that had been designed to replace the DH-4s then in use with the Air Service. Douglas won a competitive contest and was rewarded with an order for seventy five aircraft.
Three of those aircraft were completed as O-7s. They were powered by a 512hp Packard 1A-1500 direct drive engine, and had a two bladed propeller. They had the tunnel radiator used on early O-2s. They were very similar to the original O-2, and could only easily be identified by the number of exhaust stubs on the cowling - three on each side on the O-7.
At least two of the O-7s took part in the 1927 air exercises, where they served with the 12th and 16th Observation squadrons. They were later converted to the O-2 standard by giving them Liberty engines. Two became O-2s, with tunnel radiators, while the third became an O-2C with a frontal radiator mounted above the engine.
The Douglas O-8 and O-9 were also originally meant to be powered by the Packard engine, but only the O-9 was completed with it. Both of these development aircraft were also converted into O-2s.