The exceptional speed, range, armament, and bomb capacity of the 299 quickly resulted in the dramatic name _Flying Fortress_. As the B-17 it flew across the country at 232 miles per hour. In 1938, six B-17 _Flying Fortresses_ set unofficial world records for speed and range in a mass flight from Langley Field, Virginia, to Buenos Aires, Argentina, and return. [Illustration: GRUMMAN F3F NAVY FIGHTER] NAVAL AVIATION GETS READY From 1930 to 1940 the small but efficient air arm of the United States Navy continued to make progress. Since the introduction of the radial engine, the Navy had worked closely with manufacturers of this type of power plant. All types of Navy airplanes were powered with either Wright or Pratt & Whitney air-cooled, radial engines. Many problems peculiar to naval aircraft were worked out through the close co-operation of Navy technicians and manufacturers. Corrosion-resistant metals were developed for cylinders. Stronger engine parts were introduced to withstand the stress of dive-bombing. Continual progress was made in increasing the power of the engine without increasing its weight per horsepower. Thus engine power increased from 200 horsepower in 1925 to 1,000 horsepower in 1940. [Illustration: GRUMMAN F4F _WILDCAT_ NAVY FIGHTER] Naval aviators, encouraged by pioneer flying officers such as Jack Towers, Marc Mitscher, Reeves, Bellinger, Read, and others, flew continually to improve their flying and tactical techniques. They flight-tested experimental planes, invented and perfected the technique of dive-bombing, and improved their skill in the difficult task of carrier operations. A young lieutenant, Frank D. Wagner, who invented dive-bombing almost twenty years ago, a rear admiral in World War II, had the satisfaction of seeing his invention, at the peak of perfection, operating with deadly effect against our enemies in the Pacific. In fact, many of the young naval aviators who fifteen years before were conducting a continual competition to see whose squadron could excel the rest in flying, dive-bombing, and gunnery, commanded the greatest naval air force in the world. In addition to the development of carrier-based aircraft operation, the Navy perfected a catapult device which simplified the launching of planes from all types of surface vessels. In 1912 the air-minded Captain Chambers had made a successful experiment with a catapult-launching device. This device, made of material salvaged from a scrap heap, laid the foundation for catapult-launching of aircraft from surface vessels. In Captain Chambers’ device the plane rested on a small car running on the catapult rail. A cylinder filled with compressed air contained a piston. When a valve was opened, the escaping air pushed the piston against the car with a force that sent the car down the catapult rail and the plane into the air.