Solar MS 1

The Solar MS-1 was a prototype airliner built in the United States in 1930. It was a sesquiplane design, its wings braced to each other with warren truss-style struts. The stubby lower wings carried the divided main units of the fixed undercarriage. The fuselage was of rectangular cross-section and featured a fully enclosed flight deck and passenger cabin. The tail was of conventional design with strut-braced stabilizers and carrying a fixed tailwheel. Construction was of metal throughout, and the aircraft was powered by a single radial engine in the nose.

The MS-1, registered X258V, flew for the first time on 21 January 1930 with Doug Kelly at the controls. Kelly described it as "one of the finest closed planes I have ever flown", and Charles Lindbergh also praised the MS-2 when he flew it a few days later. Despite this, airlines did not order the type, although Northwest Airways considered buying ten examples. Solar made the prototype available for charter types for a while, but in 1931 sold it to an operator in Mexico who used it to transport coffee beans. On the Mexican register as XB-AFK, the MS-1 was destroyed in a crash in 1936.