After some modifications they soon had three new prototype aircraft.

This P-5 design was abandoned in 1951 and no prototype aircraft were ever built.

The first prototype aircraft powered by the 211A appeared in late 1937.

Two prototype aircraft were built, the first flying on 13 October 1922.

A contract for seven prototype aircraft was issued in October 1964.

He has complained that the prototype aircraft was 3,000 pounds over its weight limit.

The prototype aircraft made its maiden flight on February 9, 1937.

Designation for the two prototype aircraft ordered but not completed.

A prototype aircraft has been flying since 2006 but certification and production remain uncertain.

Of the prototype aircraft produced, two of the four still exist.