BOEING 367-80

The 'Boeing 367-80', or "Dash 80" as it was called within Boeing, was a concept jet transport built to demonstrate that high speed jet transport was no longer the sole preserve of military aircraft.
Considered to be the prototype for both the Boeing 707 airliner and the C-135 series aircraft (including the best known variant, the KC-135 air tanker used by the United States Air Force), the Dash 80 was built in less than two years from project launch in 1952 to rollout on May 14, 1954 for a cost of US$16 million. This was at the time an enormous risk for the Boeing Company, since they had no committed customers for the project.

Contents

Background

Model number

History

The barrel roll

Life as an experimental aircraft

Final flight

Specifications (367-80)

External links

Notes and references

Related content

Background

By the late 1940s, two developments were encouraging Boeing to begin considering the possibility of building a passenger jet.
The first was the maiden flight in 1949 of the world’s first jet airliner, the de Havilland Comet. With its 500mph cruise speed, it promised to significantly reduce journey times compared with existing propeller-powered aircraft. Boeing President Bill Allen led a company delegation to Britain in the summer of 1950 where they saw the Comet fly at the Farnborough Air Show, and also visited the de Havilland factory at Hatfield, Hertfordshire where the Comets were being built.
The second event was completion by 1950 of successful development of the B-47 jet bomber. Boeing felt that this program had enabled it to master the swept wing and podded engines which it saw as key technologies that would enable it to improve on the performance of the Comet.
In 1950, Boeing tentatively produced a specification for a jet airliner which it dubbed the Model 473-60C.^[1] However the airlines were unconvinced Boeing 367-80 National Air and Space Museum because they had no experience with jet transports, and were enjoying success with piston engined aircraft such as the Douglas DC-4, DC-6, Boeing 377, and Lockheed Constellation.
There was also a broader problem: Boeing was experienced at selling to the military, but had not enjoyed the same success with civil airliners. This market was dominated by Douglas who was adept at meeting the needs of airlines by refining and developing its range of propeller-driven aircraft, and in 1950 were actively marketing the forthcoming DC-7. Boeing decided that the only way to overcome the airlines' suspicion of the jet - and of itself - was to show them a completed aircraft.^[2]

Model number

As the first of a new generation of passenger jets, Boeing wanted the plane's model number to emphasise the difference from its previous propeller-driven aircraft which bore 300-series numbers. The 400-, 500- and 600-series were already used by missiles and other products, so Boeing decided that the jets would bear 700-series numbers, and the first would be the 707.^[3]
However, just after the program was approved, Boeing changed the designation as a disinformation tactic intended to mislead its competitors. "367" was the Boeing model number of the KC-97 Stratotanker, a previous generation aircraft to which the Dash 80 owed nothing. In fact, the Dash 80 was closer in relation to Boeing's B-47 Stratojet.

History

By early 1952 the designs were complete, and in April 1952 the Boeing board approved the program to build the jet. Construction of the Dash 80 took place at Boeing's Renton, Washington plant, but as a prototype there was no production line and most of the parts were custom built. The plane's interior was not fitted with an airline cabin; rather it consisted of a basic plywood lining that was used to house the test instrumentation required for the flight test program.
The Dash 80 was rolled out of the factory on May 15, 1954,^[4] and the maiden flight took place July 15, 1954. A series of test flights followed during which the most significant issue discovered was a marked propensity to "Dutch roll" - an alternating yawing and rolling motion. Boeing already had considerable experience with this on the B-47 and B-52, and had developed a yaw damper system on the B-47 that could be adapted to later swept wing configurations like the Dash 80. Other problems were found with the engines and brakes, the latter failing completely during landing on one occasion causing the aircraft to overshoot the runway and suffer damage.^[5]
In addition to the flight testing program, Boeing also used the Dash 80 to provide demonstration flights to airline executives and other key industry figures. These focused attention on the question of what the cabin of a passenger jet should look like. In a significant departure from its usual practice, Boeing hired industrial design firm Walter Dorwin Teague to create a cabin as radical as the plane itself.^[6]

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 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 a barrel roll at 500 feet to show off the jet airliner.^[7]
The next day, Allen summoned Johnston to his office and told him not to perform such a maneuver again, notwithstanding Johnston's assertion that doing so was completely safe. To date Johnston is the only pilot known to have performed a roll in a four engine jet transport. Other big four engine jet aircraft have done barrel rolls; for instance, the Avro Vulcan XA890 was rolled by Roly Falk on the first day of the 1955 Farnborough Air Show, but it was a bomber. The barrel roll story appears on a video called 'Frontiers of Flight - The Jet Airliner', produced by the National Air and Space Museum in association with the Smithsonian Institution in 1992.⁷
The legacy of the 707 barrel roll lives on; Boeing Chief Test Pilot John Cashman has stated that just before he piloted the maiden flight of the Boeing 777 on June 12, 1994, his last instructions from then-Boeing President Phil Condit were "No rolls."

Life 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. These tests required the fitting of a fifth engine on the rear fuselage to simulate the 727's third engine.
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 take-off and landing.

Final flight

In May 1972 Boeing retired the Dash 80 from active testing work, and donated it to the Smithsonian Air and Space Museum. For the next 18 years the plane was stored at a airplane graveyard in Arizona before being returned to Boeing in 1990 for restoration. The Dash 80's final flight was to Dulles International Airport near Washington, D.C. on August 27, 2003. She was put on display at the Steven F. Udvar-Hazy Center, an annex of the Smithsonian Institution's National Air and Space Museum located at Dulles.

Specifications (367-80)

Boeing 367-80

External links

★ Boeing 367-80 history on Boeing.com

★ Boeing 707 family history (including 367-80) on Boeing.com

★ Boeing 367-80 page on AviationHistoryOnline.com

Notes and references

★ Clive Irving, (1994), Coronet, ''Wide Body: The Making of the Boeing 747''. ISBN 0-340-59983-9
1. ''Irving, p. 166''.
2. ''Irving, p. 167-169''.
3. ''Irving, p. 171''.
4. ''Irving, p. 173''.
5. ''Irving, p. 179''.
6. Boeing's relationship with Walter Dorwin Teague has continued to the present day.
7. Video interview with Tex Johnston about barrel roll

Related content