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Birth of an Icon

In Uncategorized on March 26, 2019 by hillermuseum Tagged:

50 years of the Boeing 747
By Jon Welte

Immediately following World War II, aeronautical technologies developed for war were applied to civilian use. In the realm of commercial air transport, a series of developments over two decades converged in the creation of the remarkable Boeing 747 – an aircraft that first flew half a century ago this February.

Well into the 1940s, even jet-powered airplanes had straight wings. In 1935, German engineer Adolf Busemann realized that rearward-swept wings would reduce drag at extreme speeds. World War II ended before aircraft such as the Messerschmitt P.1101 could take flight, but its elegant swept-wing shape foreshadowed many aircraft to follow.

Swept wings were useful for bombers as well. In 1945 a team of US engineers in Germany under Dr. Theodore von Karman discovered documents related to swept-wing aircraft. The discovery was quickly incorporated into a new medium bomber proposal under development at Boeing, a project that became the B-47 Stratojet.

Originally conceived as a straight-winged bomber, the B-47 evolved into the archetype for the modern jetliner. The German-style swept wing allowed for exceptional performance; six turbojet engines were placed in pods slung under the wings, to facilitate easy servicing or replacement and to dampen out instability. First flown in 1947, over 2,000 B-47s were built for the United States Air Force to serve in the Cold War.

While Boeing’s B-47 line prospered, by 1950 commercial aviation was dominated by piston-engined airplanes built by Douglas and Lockheed. Boeing sought to use the B-47’s technologies to re-establish itself in airliners. The result was the Model 367-80 prototype. Debuting in 1954, the -80 featured the swept wings and podded, underwing engines seen on the B-47. In 1955 Pan American World Airways ordered 20 of the larger production version, the Boeing 707. The 707 and aircraft like it transformed the face of air transportation, making long distance flights faster, smoother and safer than any air voyages had been before.

The success of the 707 emboldened Juan Trippe, Pan Am’s president, to push Boeing for development of an even larger jetliner. Boeing had participated in an Air Force competition in 1963 to build a large military airlifter. While Boeing lost the competition to Lockheed’s C-5, the effort created the foundation for the new aircraft. Designed under the leadership of Boeing engineer Joe Sutter, the new jetliner was intended to be capable of serving as a cargo carrier as well as an airliner. The wide main deck required two aisles when configured for carrying passengers, a first for a jet-powered airliner. And to facilitate the envisioned cargo mission, the flight deck would be placed on an upper level far above the passengers.

The 747’s upper level was not originally intended for passenger seating. The positioning of the flight deck atop the fuselage created extra drag on the aircraft at high speeds. Elongating the area behind the cockpit into an extended “hump” substantially reduced this drag. The relationship between wing area, fuselage area and drag was first recognized by German scientists during World War II, but was not adapted to postwar aircraft design until American aerodynamicist Richard Whitcomb rediscovered and published the idea as the so-called “area rule” in 1952. Ironically, Whitcomb’s inspiration was a lecture given by Adolf Busemann, father of the swept wing and a post-war immigrant to the United States.

The final key component of the 747 was its engine. Turbojet engines equipped the early 707s, but high fuel consumption made them unsuitable for a gigantic airplane intended to fly long distances. The Air Force competition that resulted in the Lockheed C-5 stimulated development of new high bypass turbofan engines. These engines direct large quantities of air around the engine core, mixing it with the hot exhaust blast. As much of the air entering the engine did not need to pass through the core, efficiency was boosted substantially. Boeing selected Pratt & Whitney to build the JT9 to power its 747.

The 747’s first flight took place at Everett, Washington on February 9, 1969. An extended period of testing followed which uncovered a range of teething issues, particularly with the engine. For a time, 747 production substantially outpaced JT9 engine production and dozens of engineless 747s accumulated on the ramp outside Boeing’s factory. In time, however, problems with the JT9 were resolved. The combination of size and range provided by the 747 gave it capabilities never before available in air transport. Many of the world’s premier airlines ordered it in quantity, as there was simply no substitute for it on many long range international routes.

Over the past half century over 1500 747s have been built in several major versions. The latest iteration is the 747-8, which entered service in 2011. While outwardly similar to the 747 of 1969, the -8 has new engines, improved wingtips, a lengthened fuselage and a host of technological improvements. Despite this, the 747 has been increasingly supplanted by smaller and more efficient twinjet airplanes able to fly comparable distances with more modest passenger loads. While existing 747s will continue to fly passengers for years to come, future production is likely to consist primarily of freighters – finally validating Joe Sutter’s guess from a half century before.

Since 1998 the Hiller Aviation Museum has exhibited the forward section and flight deck of a former British Airways Boeing 747-100. Sporting the livery of exhibit sponsor and Museum support Al Silver’s Flying Tigers cargo airline, the exhibit provides thousands of visitors each year an unparalleled opportunity to explore the flight deck of this remarkable aircraft.

Resources

747: Creating the World’s First Jumbo Jet, Joe Sutter and Jay Spenser, 2006

Boeing 747 – Design and Development Since 1969, Guy Norris and Mark Wagner, 1997

The Sporty Game, John Newhouse, 1982

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