History[]
Built by Boeing to demonstrate the advantages of jet propulsion for commercial aviation, N70700t served as basis for the design of the KC-135 tanker and the 707 airliner.
Operational history[]
By early 1952 the designs were complete and in April the Boeing board approved the program. Construction of the Dash 80 started in November in a walled-off section of Boeing's Renton plant.[1] As a proof of concept prototype there was no certification and no production line and most of the parts were custom built. The aircraft was not fitted with an airline cabin; a plywood lining housed the instrumentation for the flight test program.
The Dash 80 rolled out of the factory on May 15, 1954, two years after the project was approved and 18 months after construction had started.[2] During a series of taxi trials the port landing gear collapsed on May 22; the damage was quickly repaired and the first flight was on July 15, 1954.
Following flights revealed a propensity to "Dutch roll" - an alternating yawing and rolling motion. Boeing already had experience with this on the B-47 Stratojet and B-52 Stratofortress and had developed a yaw damper system on the B-47 that could be adapted to the Dash 80. Other problems were found with the engines and brakes, the latter once failing completely on landing causing the aircraft to overshoot the runway.[3]
Boeing used the Dash 80 on demonstration flights for airline executives and other industry figures. These focused attention on the question of what the cabin of a passenger jet should look like. In a departure from its usual practice Boeing hired industrial design firm Walter Dorwin Teague to create a cabin as radical as the aircraft itself.
Prior to demonstration for passenger airlines, the Dash 80 was fitted with Boeing's Flying Boom for aerial refueling which served as a prototype for the KC-135 Stratotanker and its later derivatives.
The barrel roll[]
As part of the Dash 80's demonstration program, Bill Allen invited representatives of the Aircraft Industries Association (AIA) and International Air Transport Association (IATA) to the Seattle's 1955 Seafair and Gold Cup Hydroplane Races held on Lake Washington on August 6, 1955. The Dash 80 was scheduled to perform a simple flyover, but Boeing test pilot Alvin "Tex" Johnston instead performed two barrel rolls to show off the jet airliner.[4]
The next day, Allen summoned Johnston to his office and told him not to perform such a maneuver again, to which Johnston replied that he was simply "selling airplanes" and asserted that doing so was completely safe.[5][N 2]
Use as an experimental aircraft[]
After the arrival of the first production 707 in 1957 the Dash 80 was adapted into a general experimental aircraft and used by Boeing to test a variety of new technologies and systems. One of its most important tasks during the late 1950s was to test systems for the new Boeing 727, including the fitting of a fifth engine in the rear fuselage.[6] Other tests included experiments with different airfoil shapes and a number of high lift devices such as blown flaps, in which compressed air bled from the engines is directed over the flaps to increase lift during takeoff and landing.
Final flight[]
After 2,350 hours and 1,691 flights the aircraft was withdrawn from use in 1969 and placed in storage.[7] On May 26, 1972 Boeing donated the 367-80 to the Smithsonian Air and Space Museum, which had designated it one of the 12 most significant aircraft of all time.[7] For the next 18 years the aircraft was stored at a "desert boneyard" now called the 309th Aerospace Maintenance and Regeneration Group (AMARG) at Davis-Monthan Air Force Base near Tucson, Arizona before being retrieved by Boeing in 1990 for restoration. The Dash 80's final flight was to Dulles International Airport near Washington, D.C. on August 27, 2003. Repainted to its original yellow and brown Boeing livery, it was put on display at the Steven F. Udvar-Hazy Center, an annex of the Smithsonian Institution's National Air and Space Museum, located adjacent to Dulles Airport in Chantilly, Virginia.Cite error: Closing </ref> missing for <ref> tag
Notes[]
- ↑ Footage of the Boeing 367-80, prototype of the 707, during its roll-out in May 1954.
- ↑ The contention that the maneuver was dangerous was refuted by Johnston himself. "It's a one-g maneuver. It's absolutely nonhazardous, but it's very impressive," explained Johnston to Allen. Other big four-engine jet aircraft have since done barrel rolls.[4]
Sources[]
- ↑ Thompson, R.G. "Dash 80 The story of the prototype 707." Air & Space Magazine, May 1, 1987. Retrieved: April 3, 2010.
- ↑ Irving, Clive. Wide Body: The Making of the Boeing 747. Philadelphia: Coronet, 1994. ISBN 0-340-59983-9. Page 173.
- ↑ Irving. 1994. Page 179.
- ↑ 4.0 4.1 "Video interview with Tex Johnston about barrel roll." aviationexplorer.com. Retrieved: April 3, 2010.
- ↑ "It's Possible to Roll This Airplane." Flying Magazine, Vol. 135, No. 5, May 2008, p. 48.
- ↑ "Boeing 367-80." National Air and Space Museum, Smithsonian Institution, 2004. Retrieved: February 22, 2007.
- ↑ 7.0 7.1 Tony Pither. The Boeing 707 720 and C-135. Tonbridge, Kent, UK: Air-Britain (Historians) Ltd, 1998. ISBN 0-85130-236-X Page 13. Cite error: Invalid
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