Curtiss F6C-1 Hawk - 1926 Schneider Cup Race

This image is available from the United States Library of Congress's Prints and Photographs division under the digital ID npc2007016207

The U.S. Navy Schneider Cup team was photographed on August 19, 1926 in front of the Curtiss F6C-1 Hawk. The pilot was Lt.  William Tomlinson (later Rear Admiral, 2nd from left). The Curtiss hawk was powered by a 507 HP Curtiss D12-A engine and achieved a speed of 220.406 km/h during the race but made only the 4th of 4 contenders participating.

Virtual Tour of the National Museum of the US Air Force

A Virtual Tour of the National Museum of the US Air Force (photo by U.S. Air Force)

The National Museum of the US Air Force is a large repository of U.S. military aircraft. Having been there a couple of times, I can attest that this virtual tour is, of course, no substitute for an actual visit, but it comes close and is nicely executed. More information on the Virtual Tour, or click on the link about to go to the tour itself. 

Curtiss D-12 engine

Curtiss D-12 engine at the National Museum of the United States Air Force in Dayton, OH -- (U.S. Air Force photo)

The 375-hp Curtiss D-12 engine, introduced in 1921, was a liquid-cooled V-12. It was one of the most  successful aircraft engines of the 1920s. The D-12 replaced the gears connecting the crankshaft to the propeller with a more reliable direct-drive connection, hence the "D" for direct-drive. However, as demonstrated by the Macchi M.33 in the 1925 race that was powered by a 1923 Curtiss D-12 engine rated at 507 horsepower, total horsepower was often the deciding factor in the Schneider races..

The Curtiss V-1400 and its link to the D-12

According to William Bevan (New Aircraft Engines, Purdue Engineering Review, Vol. 18-22), the Curtiss V-1400 was developed to meet the requirements for an engine of about 500 horsepower with minimum weight and great reliability The engine had a bore of 4.875 inches; stroke 6.15 inches; and compression  ratio 5.5 to 1. It was rated at 510 horsepower at 2,100 rpm. The weight was 660 pounds or 1.3 pounds per horsepower. It was engine was 75 pounds lighter than its nearest competitor in the 500 horsepower class.  Both United States Army and Navy racing entered in the Pulitzer and Schneider cup races of 1925 were powered with engine and new world's speed records were established in both races Lieutenant Bettis of the Army Air Service.

According to Hugo T. Byttebier, (The Curtiss D-12 Aero Engine, Smithsonian Annals of Flight, Number 7): “One result of the crystallization of the D-12 design at Curtiss was that demands for more power, which inevitably were to be made, could be met only by enlarging the size of the cylinders in new models, without changing the basic design. We have already encountered the D-12A of 1923, which had had its bore increased by one-eighth inch and was able to develop about 500 bhp for racing. It was not rated for service, however, and only a few units were built. The design of a bigger engine, the V-1400 was started in 1924. It was introduced in the 1925 Pulitzer race, which it had no difficulty in winning, and it did not encounter any worthwhile opposition at the Schneider Trophy contest.”

According to Byttebier, (The Curtiss D-12 Aero Engine, Smithsonian Annals of Flight, Number 7): “The V-1400 had its bore enlarged by another quarter inch (to 4% in.) and its stroke also increased by a quarter inch (to 6V4 in.). This engine gave 620 bhp on the test bench, and it was even lighter than the D-12. The only departure from the basic D-12 design was the important one of using open-ended cylinder liners. The V-1400 passed a 50-hour test at 500 bhp in 1924 but it was not put into production. Twelve units were built, five of which were destined for the P-2 fighter.”

Papercraft model of Curtiss RC3-2

Photo of Curtiss RC3-2 paper model-taken from Japanese site by Takumi. 

A wonderful Japanese Papercraft site that contains a model of the Curtiss R3C-2 as well as the Macchi MC-72. More >>

Schilt and the 1926 R3C-2 at Hampton Roads

 Schilt and the R3C-2 at Hampton Roads. (NASM-9A06382). 

During the November 1926 Schneider Trophy competition at Hampton Roads, Virginia, Marine Corps Lt. C. Frank Schilt placed second at an average speed of 372 km/h (231.4 mph) in the R3C-2. Pictured above is Schilt and the R3C-2 at Hampton Roads. (NASM-9A06382). This plane is now displayed in the Pioneers of Flight gallery at the National Air and Space Museum in Washington, DC. For more on the Curtiss R3 racers, see The Curtiss R3C-2 Racer, 1925.

Macchi M.33 powered by D-12 engine

It is interesting to note that the Macchi M.33 in the 1925 race was powered by a 1923 Curtiss D-12 engine rated at 507 horsepower. And it was also the last flying boat to compete in the Schneider races.

Silent film of the 1925 Schneider Trophy Race

A silent film of the 1925 Schneider Trophy Race





The 1925 race was flown off Bay Shore Park, Maryland, (near Baltimore). Lt. James Doolittle, USA, flying the Army’s entry, a Curtiss R3C-2, was the winner. The U.S. was represented by both Army and Navy entries. According to The Navy's Schneider Cup Racers by Lieutenant Colonel Robert H. Rankin, U.S. Marine Corps, the Army airplane, was the same landplane (designated R3C-1), which had won the Pulitzer Races a few weeks previous to the Schneider contest. Converted to a sea plane by the removal of its wheeled landing gear and the addition of twin floats, it was flown at an average speed of 232.573 m.p.h. to win the contest. An equal-span biplane with a span of 22 feet and a length of 20 feet, two inches, it was powered by a 619-h.p. Curtiss V-1400 liquid-cooled engine.

The British entry was a Gloster Napier III and Italian was a Macchi M.33 Flying Boat.

Curtiss V 1400 engine of 1925

"The Curtiss V 1400 is similar in type its predecessor the D 12 The V 1400 to meet the requirements for an engine of about 500 horsepower of minimum weight with great reliability The bore is 4.875 inches stroke 6.15 inches compression ratio 5.5 to 1 The engine is rated at 510 horsepower at 2,100 rpm Its weight is 660 pounds or 1.3 pounds per horsepower However the engine is said to deliver 619 horsepower at 2,500 rpm or one horsepower for each 1.07 pounds of weight Even at 1.3 pounds of weight per horsepower it is the lightest engine of its power in successful use at present It is stated that this engine is 75 pounds lighter than its nearest competitor in the 500 horsepower class Both the United States Army and Navy racing planes entered in the Pulitzer and Schneider cup races of 1925 were powered with this engine and new world's speed records were established in both races." Text from the The Purdue Engineer, Volumes 18-22 - Page 4 , AIRCRAFT ENGINES Villiam A Bevan Major Air Service Reserve.

Curtiss R3C-2

The Curtiss R3C-2 flown by U.S. Army Lt. James Doolittle took first place in the Schneider Trophy Race of 1925 with an average speed of 374 km/h (232.17 mph). The plane had a Curtiss V-1400 Engine, a V-type, 12 cylinder, water-cooled engine rated at 665 hp.