US Air Force Republic XF-12 Rainbow

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The Republic XF-12 Rainbow was an American four-engine, all-metal reconnaissance aircraft designed by the Republic Aviation Company in the late 1940s for the then US Army Air Forces. The XF-12 prototype was designed with four Pratt & Whitney engines to reach a cruising speed of 400 mph and a range of 4,000 miles while flying at 40,000 feet. The aircraft was also designed to maximize aerodynamic efficiency while flying. Despite the XF-12’s many innovations, the end of World War II and the advent of the jet engine rendered the aircraft obsolete before it would enter production.

The XF-12’s primary mission was reconnaissance and to accomplish that the aircraft was designed with photo equipment for day and night photography. The XF-12 was also designed with complete darkroom facilities on board to allow for the developing and printing of the film while still airborne.

The “Operation Birds Eye” mission was developed to demonstrate the XF-12’s reconnaissance capabilities. On 1 September 1948, a second prototype XF-12 departed the U.S. Air Force Flight Test Center at Muroc, California, and climbed west heading over the Pacific Ocean to its 40,000 ft cruising altitude before then heading east. The aircraft then photographed the entire flight path across the United States.

During this 1948 flight, the XF-12, 44-19003, passed over Alamosa, Colorado and then over the city of Albuquerque, New Mexico.
The aircraft eventually landed at Mitchell Field on Long Island, New York after a six hour and 55 minutes flight that averaged a speed of 361 mph the entire journey. During the flight, a photo was taken approximately every minute and 390 individual 10 inch photos, each covering about 490 miles, were joined together to form a continuous 325 foot long print.

The flight was featured in the 29 November 1948 issue of Life magazine and the filmstrip was exhibited at the 1948 U.S. Air Force Association Convention in New York City. Although the XF-12 program had already been canceled when this flight was made, this aircraft represented the latest in streamlined design, engine efficiency, augmented thrust, and high altitude operation, in addition to the improved reconnaissance capabilities.

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