From the Planes You’ve (Probably) Never Heard Of Department of Planelopnik, we bring you the Lockheed R6V Constitution.
Throughout aviation history, there have been numerous double-deck aircraft. Most were just very large aircraft with two decks, but some were so-called “double bubble” aircraft. Since pressurized aircraft are essentially an aluminum tube, a double bubble aircraft stacks one tube atop the other to make more cabin or cargo space. For an example, take a look at the Boeing C-97 Stratofreighter. It was developed from the Boeing B-29/B-50 Superfortress, which was enlarged by the addition of a larger diameter tube on top of the original tube. The Hawker Siddeley Nimrod, though not a double-decker, was created by stacking a second tube atop a de Havilland Comet airliner. But unlike those aircraft conversions, the Lockheed Constitution was built from the ground up to be a double bubble double-decker.
Development of the R6V began in 1942 with a joint study by the US Navy, Pan Am and Lockheed to develop a large transport aircraft to supplement the Navy’s aging fleet of flying boats. Pan Am signed on in the hopes that any aircraft coming out of the partnership might also have commercial applications. Design specifications stated that the fully pressurized aircraft would be capable of carrying 17,500 pounds of payload at an altitude of 25,000 feet for 5,000 miles. And when the Constitution was finished, it was big. Though the mammoth Martin JRM Mars flying boat had a greater wingspan by 11 feet, the Constitution would be the largest fixed wing aircraft ever flown by the US Navy. And there would be only two.
Constitution No. 1 arriving at NAS Jacksonville, Florida, 1949
Ship No. 1 was completed in 1946 and took its maiden flight on November 9 of that year. Flight testing showed the engines to be significantly underpowered, so they were replaced by more powerful Pratt & Whitney R-4360-22-W engines with water injection that offered 3,500 HP. Rockets could also be mounted under the wings to assist in takeoffs with heavier payloads. Ship No. 2 took its maiden flight on June 9, 1948 and had an upper deck sumptuously fitted out for 92 passengers and 12 crew. The lower deck was fitted for cargo, but could also be configured to carry 76 passengers in addition to those on the upper deck. On February 3, 1949, Ship No. 2 flew 74 members of the press from Moffett Field in California to Washington National Airport, setting a record for the most passengers transported on a nonstop transcontinental flight.
Lockheed RV6 Constitution performing a rocket-assisted takeoff
In the end, the Constitution couldn’t live up to its billing. It proved to be too underpowered, even with its engine upgrade, and problems with engine overheating led to a reduced operational range. In 1949, the Navy decided that the aircraft were just too expensive to operate and offered to lease them to the airlines. But there were no takers. Both aircraft were eventually sold for $97,785 in a deal that included 13 engines, which is a pretty good bargain when you consider that the contract to build the two aircraft cost $27 million. After the sale, both Constitutions suffered ignominious fates. Ship No. 1 was taken to Las Vegas where it was used as a giant billboard for Alamo Airways. It ended up being scrapped by Howard Hughes when he bought the property. Ship No. 2 was taken to Opa-Locka Airport in Florida and stored at the airfield. It was eventually moved off the airport to a new storage site, and there were plans to use it as a restaurant and museum. But those plans fell through, and the aircraft was finally scrapped in 1978.
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Photo credits: First photo: W.T Larkins via Wikimedia Commons; Second photo: NACA; Third photo: US Navy; Fourth photo: Author unknown