Thomas-Morse TM-24

The Thomas-Morse TM-24 was a prototype American two-seat observation aircraft of the 1920s. A single example was built in 1925, but no production followed.

Design and development
Thomas-Morse Aircraft had decided to specialize in all-metal aircraft after it lost an order for 200 MB-3 fighters to Boeing, who had offered a much lower bid. Thomas Morse's chief designer, B. Douglas Thomas produced a series of all-metal aircraft, flying the unsuccessful MB-9 fighter and MB-10 trainer in 1921, and selling two R-5 racing aircraft to the United States Army Air Service in 1922. In 1924, Thomas-Morse flew the TM-23, a single-seat biplane fighter, which was again a failure, undergoing major redesign in an attempt to improve performance and handling but failing to obtain any orders.

In 1924, Thomas designed a single-engined two-seat observation aircraft, the TM-24, in a further attempt to find success with all-metal construction. The TM-23 had a short fuselage in an attempt to improve maneuverability, which was covered in corrugated aluminium skinning, with the crew of two sitting in separate, tandem cockpits. The upper wing was much smaller than the lower wing, having a wingspan 5 feet less, with the wings braced by a single "N"-strut and an inverted "V"-strut on each side. Additional auxiliary tail surfaces were mounted on the aircraft's fin, above the main tailplane, which acted as trim tabs. The aircraft was powered by a 440 hp Curtiss D12 water-cooled V12 engine driving a two-bladed propeller and cooled by radiators located in fairings in the lower wing-roots.

The TM-23 flew in early 1925, being delivered to McCook Field for testing by the Army Air Service in February that year. While testing indicated that performance was good, the aircraft's landing speed was considered too-high, while its rudder was masked if the observer stood up in his cockpit to use his machine gun, while the TM-24 was also considered frail by the testers. Further development was abandoned, with the prototype being dismantled at McCook Field, Thomas-Morse losing $46,000 on the project.