Steven F. Udvar-Hazy Center: North American P-51C, “Excalibur III”
Image by Chris Devers
Quoting Smithsonian National Air and Space Museum | North American P-51C, "Excalibur III":
On May 29, 1951, Capt. Charles F. Blair flew Excalibur III from Norway across the North Pole to Alaska in a record-setting 10½ hours. Using a system of carefully plotted "sun lines" he developed, Blair was able to navigate with precision where conventional magnetic compasses often failed. Four months earlier, he had flown Excalibur III from New York to London in less than 8 hours, breaking the existing mark by over an hour.
Excalibur III first belonged to famed aviator A. Paul Mantz, who added extra fuel tanks for long-distance racing to this standard P-51C fighter. With it Mantz won the 1946 and 1947 Bendix air race and set a transcontinental speed record in 1947 when the airplane was named Blaze of Noon. Blair purchased it from Mantz in 1949 and renamed it Excalibur III, after the Sikorsky VS-44 flying boat he flew for American Export Airlines.
Gift of Pan American World Airways
North American Aircraft Company
Country of Origin:
United States of America
Wingspan: 11.3 m (37 ft)
Length: 9.8 m (32 ft 3 in)
Height: 3.9 m (12 ft 10 in)
Weight, empty: 4,445 kg (9,800 lb)
Weight, gross: 5,052 kg (11,800 lb)
Top speed: 700 km/h (435 mph)
Single seat, single engine, low wing monoplane, World War II fighter modified for racing.
• • • • •
On July 15, 1954, a graceful, swept-winged aircraft, bedecked in brown and yellow paint and powered by four revolutionary new engines first took to the sky above Seattle. Built by the Boeing Aircraft Company, the 367-80, better known as the Dash 80, would come to revolutionize commercial air transportation when its developed version entered service as the famous Boeing 707, America’s first jet airliner.
In the early 1950s, Boeing had begun to study the possibility of creating a jet-powered military transport and tanker to complement the new generation of Boeing jet bombers entering service with the U.S. Air Force. When the Air Force showed no interest, Boeing invested million of its own capital to build a prototype jet transport in a daring gamble that the airlines and the Air Force would buy it once the aircraft had flown and proven itself. As Boeing had done with the B-17, it risked the company on one roll of the dice and won.
Boeing engineers had initially based the jet transport on studies of improved designs of the Model 367, better known to the public as the C-97 piston-engined transport and aerial tanker. By the time Boeing progressed to the 80th iteration, the design bore no resemblance to the C-97 but, for security reasons, Boeing decided to let the jet project be known as the 367-80.
Work proceeded quickly after the formal start of the project on May 20, 1952. The 367-80 mated a large cabin based on the dimensions of the C-97 with the 35-degree swept-wing design based on the wings of the B-47 and B-52 but considerably stiffer and incorporating a pronounced dihedral. The wings were mounted low on the fuselage and incorporated high-speed and low-speed ailerons as well as a sophisticated flap and spoiler system. Four Pratt & Whitney JT3 turbojet engines, each producing 10,000 pounds of thrust, were mounted on struts beneath the wings.
Upon the Dash 80’s first flight on July 15, 1954, (the 34th anniversary of the founding of the Boeing Company) Boeing clearly had a winner. Flying 100 miles per hour faster than the de Havilland Comet and significantly larger, the new Boeing had a maximum range of more than 3,500 miles. As hoped, the Air Force bought 29 examples of the design as a tanker/transport after they convinced Boeing to widen the design by 12 inches. Satisfied, the Air Force designated it the KC-135A. A total of 732 KC-135s were built.
Quickly Boeing turned its attention to selling the airline industry on this new jet transport. Clearly the industry was impressed with the capabilities of the prototype 707 but never more so than at the Gold Cup hydroplane races held on Lake Washington in Seattle, in August 1955. During the festivities surrounding this event, Boeing had gathered many airline representatives to enjoy the competition and witness a fly past of the new Dash 80. To the audience’s intense delight and Boeing’s profound shock, test pilot Alvin "Tex" Johnston barrel-rolled the Dash 80 over the lake in full view of thousands of astonished spectators. Johnston vividly displayed the superior strength and performance of this new jet, readily convincing the airline industry to buy this new airliner.
In searching for a market, Boeing found a ready customer in Pan American Airway’s president Juan Trippe. Trippe had been spending much of his time searching for a suitable jet airliner to enable his pioneering company to maintain its leadership in international air travel. Working with Boeing, Trippe overcame Boeing’s resistance to widening the Dash-80 design, now known as the 707, to seat six passengers in each seat row rather than five. Trippe did so by placing an order with Boeing for 20 707s but also ordering 25 of Douglas’s competing DC-8, which had yet to fly but could accommodate six-abreast seating. At Pan Am’s insistence, the 707 was made four inches wider than the Dash 80 so that it could carry 160 passengers six-abreast. The wider fuselage developed for the 707 became the standard design for all of Boeing’s subsequent narrow-body airliners.
Although the British de Havilland D.H. 106 Comet and the Soviet Tupolev Tu-104 entered service earlier, the Boeing 707 and Douglas DC-8 were bigger, faster, had greater range, and were more profitable to fly. In October 1958 Pan American ushered the jet age into the United States when it opened international service with the Boeing 707 in October 1958. National Airlines inaugurated domestic jet service two months later using a 707-120 borrowed from Pan Am. American Airlines flew the first domestic 707 jet service with its own aircraft in January 1959. American set a new speed mark when it opened the first regularly-scheduled transcontinental jet service in 1959. Subsequent nonstop flights between New York and San Francisco took only 5 hours – 3 hours less than by the piston-engine DC-7. The one-way fare, including a surcharge for jet service, was 5.50, or 1 round trip. The flight was almost 40 percent faster and almost 25 percent cheaper than flying by piston-engine airliners. The consequent surge of traffic demand was substantial.
The 707 was originally designed for transcontinental or one-stop transatlantic range. But modified with extra fuel tanks and more efficient turbofan engines, the 707-300 Intercontinental series aircraft could fly nonstop across the Atlantic with full payload under any conditions. Boeing built 855 707s, of which 725 were bought by airlines worldwide.
Having launched the Boeing Company into the commercial jet age, the Dash 80 soldiered on as a highly successful experimental aircraft. Until its retirement in 1972, the Dash 80 tested numerous advanced systems, many of which were incorporated into later generations of jet transports. At one point, the Dash 80 carried three different engine types in its four nacelles. Serving as a test bed for the new 727, the Dash 80 was briefly equipped with a fifth engine mounted on the rear fuselage. Engineers also modified the wing in planform and contour to study the effects of different airfoil shapes. Numerous flap configurations were also fitted including a highly sophisticated system of "blown" flaps which redirected engine exhaust over the flaps to increase lift at low speeds. Fin height and horizontal stabilizer width was later increased and at one point, a special multiple wheel low pressure landing gear was fitted to test the feasibility of operating future heavy military transports from unprepared landing fields.
After a long and distinguished career, the Boeing 367-80 was finally retired and donated to the Smithsonian in 1972. At present, the aircraft is installated at the National Air and Space Museum’s new facility at Washington Dulles International Airport.
Gift of the Boeing Company
Boeing Aircraft Co.
Country of Origin:
United States of America
Height 19′ 2": Length 73′ 10": Wing Span 129′ 8": Weight 33,279 lbs.
Prototype Boeing 707; yellow and brown.