12/31/2008. 12/31/2008. Consolidated Vultee, operating under the trade name Convair, designed the XP5Y-1 (world’s first turboprop powered flying boat) to an USN specification stipulating a high-performance long-range multi-role flying-boat executing day and night search and rescue operations, and anti-submarine patrol, able to remain at sea for several days.

The four 5,500 hp Allison T-40-A4 powerplants consisted each of two T-38 axial-flow turbine engines driving two contra-rotating co-axial Aeroproducts propellers through a common reduction gear, each T-38 capable of operating the contra-rotating propellers independently or together.

121455, the first of two prototypes, was finished in 1949, proving engine reliability problems during ground runs and it took till April 18, 1950, before it made its first flight from San Diego. In August 1950 it established a world’s durations record for turbo-prop powered aircraft of eight hours and six minutes, while by that time it was decided to discontinue the anti-submarine development.

The prototype was lost on July 15, 1953, due to failure of the elevator trim system which eventually caused uncontrollable longitudinal instability. The eleven crew bailed out safely, the prototype crashed into the sea near Point Loma, California. The second prototype, s/n 121456, never flew due to unsolved engine reliability problems and was scrapped in 1957. View also photo 2711.