Lynn Towns correctly identified the Mystery Plane that appeared in the August Vintage AirMail. He presented the following:
Mystery Plane No. 3 is the first airplane built by the Dare Aircraft Corporation in Detroit, Michigan. I can’t find a model description for this airplane, but it was built in 1921 and incorporated patented variable wings, which were intended to replace both airlerons and elevators. In order to test the variable canber concept, the airplane also had conventional controls.
The airplane was an experimental 2-place design of all metal construction. It was originally powered witha 1 40 German Benz engine, but the airplane was underpowered. I’m not sure if the airplane was ever flown with this engine, but it is doubtful. The engine was later replaced with a 400hp Liberty engine as seen in the Mystery Plane photo. n After the engine change, a test was made by Eddie Stinson at Selfridge Field at Mt. Clemens, Michigan. During the test flight the airplane didn’t fly well. It is said that during the test flight Eddie Stinson made wide, flat turns. Approximately a year later the airplane was destroyed in a crash.
Wesley Smith of Springfield, Illinois furnished detailed information regarding the Dare aircraft which can be viewed here.