Boeing 367-80

Boeing 367-80
The Dash 80 passing over a mountain range
Role	Prototype transport/airliner
Manufacturer	Boeing
First flight	July 15, 1954
Introduction	1955
Retired	1970
Produced	1954
Number built	1
Unit cost	US$16 million
Developed into	Boeing KC-135 Stratotanker Boeing 707
Other name(s)	Dash 80
Registration	N70700
Owners and operators	Boeing
In service	1954–1969
Preserved at	Steven F. Udvar-Hazy Center

The Boeing 367-80, or "Dash 80" as it was called within Boeing, is an American prototype jet transport built to demonstrate the advantages of jet aircraft for passenger transport over piston-engine airliners.

The Dash 80 is considered to have been the prototype for the KC-135 Stratotanker tanker and the 707 airliner. It 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.

Only one example of the type was built. Currently, it resides in the Steven F. Udvar-Hazy Center, an annex of the Smithsonian Institution's National Air and Space Museum located at Washington Dulles International Airport in Virginia.

Design and development

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 500 miles per hour (800 km/h) cruise speed, it promised to significantly reduce journey times compared with existing propeller-driven aircraft. Boeing President Bill Allen led a company delegation to Britain in summer 1950 where they saw the Comet fly at the Farnborough Airshow, and also visited the de Havilland factory at Hatfield, Hertfordshire where the Comets were being built. The second event was completion by 1947 of successful development of the B-47 Stratojet. 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 both the performance and the engine maintenance 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^[2] 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.^[3]

As the first of a new generation of passenger jets, Boeing wanted the aircraft's model number to emphasize 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.^[4] 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.^[2] although it did have the same 132-inch (3.35 m) fuselage diameter as the 367s and the 367s fuselage crease was smoothed out.^[5] Although the design was announced as the Model 707 the prototype was referred to simply as the "-80", or Dash 80.

The -80 fuselage was wide enough for five-abreast seating; two on one side of the aisle and three on the other. However, by the time the Boeing company committed to production, the decision had been made to design the production model 707 as a six-abreast design, with a larger-diameter fuselage 148 inches (3.76 m), based on feedback from C.R. Smith, CEO of American Airlines, who told Boeing he wouldn't buy the 707 unless it was an inch wider than the then-proposed Douglas DC-8 passenger jet.^{[citation needed]} This decision did not unduly delay introduction of the production model since the -80 had been largely hand-built, and thus little production tooling had been created for its manufacture.^[6]

Operational 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 started in November in a walled-off section of Boeing's Renton plant.^[7] As a proof of concept prototype there was no certification and no production line and most of the parts were custom built. The aircraft'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, just two years after the project was approved, and 18 months after construction had started.^[8] The 367-80 then undertook a series of taxi trials and although the port landing gear collapsed on May 22 causing damage to the airframe which was quickly repaired,^[5] the maiden flight took place on 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.^[9]

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 aircraft itself.^[10]

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 a barrel roll to show off the jet airliner.^[11]

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.^{[12][N 1]} 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.^[11]

Boeing Chief Test Pilot John Cashman 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."^[13]

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. These tests required the fitting of a fifth engine on the rear fuselage as part of tests for the 727.^[2] 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.^[14] 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.^[14] For the next 18 years the aircraft was stored at a "desert boneyard" in 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. 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.^[15]

Specifications (367-80)

General characteristics

• Length: 128 ft 0 in (39.02 m)
• Wingspan: 130 ft 0 in (39.63 m)
• Height: ()
• Wing area: 2,402 ft² (223.2 m²)
• Loaded weight: 160,000 lb (72,600 kg)
• Powerplant: 4 × Pratt & Whitney JT3 turbojets, 10,000 lbf (44.5 kN) each

Performance

• Maximum speed: over 600 mph (>965 km/h)
• Cruise speed: 550 mph (850 km/h)
• Range: 3,530 mi (5,680 km)
• Service ceiling: 43,000 ft (13,100 m)
• Wing loading: 67 lb/ft² (325 kg/m²)
• Thrust/weight: 0.3:1

See also

Aviation portal

Related development

• KC-135 Stratotanker
• C-135 Stratolifter
• C-137 Stratoliner
• Boeing 707
• Boeing 727
• Boeing 737
  

Aircraft of comparable role, configuration and era

• Convair 880
• Douglas DC-8
  

References

Notes

1. ^ 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.^[11]

Citations

1. ^ Irving 1994, p. 166.
2. ^ ^{a b c} "Boeing 367-80." National Air and Space Museum, Smithsonian Institution, 2004. Retrieved: February 22, 2007.
3. ^ Irving 1994, pp. 167–169.
4. ^ Irving 1994, p. 171.
5. ^ ^{a b} Pither 1998, p. 12.
6. ^ "707 Family." Boeing. Retrieved: April 3, 2010.
7. ^ Thompson, R.G. "Dash 80 The story of the prototype 707." Air & Space Magazine, May 1, 1987. Retrieved: April 3, 2010.
8. ^ Irving 1994, p. 173.
9. ^ Irving 1994, p. 179.
10. ^ Boeing's relationship with Walter Dorwin Teague has continued to the present day.
11. ^ ^{a b c} "Video interview with Tex Johnston about barrel roll." aviationexplorer.com. Retrieved: April 3, 2010.
12. ^ "It's Possible to Roll This Airplane." Flying Magazine, Vol. 135, No. 5, May 2008, p. 48.
13. ^ Wallace, James. "After 40 years at Boeing, chief test pilot John Cashman is retiring." seattlepi.nwsource.com, January 12, 2007. Retrieved: April 4, 2009.
14. ^ ^{a b} Pither 1998, p. 13.
15. ^ Hanser, Kathleen and Claire Brown. "Historic Boeing Dash 80 Aircraft Makes Final Flight to Dulles for Display at National Air and Space Museum's Companion Facility, the Steven F. Udvar-Hazy Center." Smithsonian Institute. Retrieved: April 3, 2010.

Bibliography

• Bowers, Peter M. Boeing aircraft since 1916. London: Putnam Aeronautical Books, 1989. ISBN 0-85177-804-6.
• Irving, Clive. Wide Body: The Making of the Boeing 747. Philadelphia: Coronet, 1994. ISBN 0-340-59983-9.
• Tony Pither. The Boeing 707 720 and C-135. Tonbridge, Kent, UK: Air-Britain (Historians) Ltd, 1998. ISBN 0-85130-236-X
• Wilson, Stewart. Airliners of the World. Fyshwick, Australia: Aerospace Publications Pty Ltd., 1999. ISBN 1-875671-44-7.

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^{[dead link]}