Boeing 367-80

https://en.wikipedia.org/wiki/Boeing_367-80

The Boeing 367-80, known simply as the Dash 80, is an American quadjet prototype
aircraft built by Boeing to demonstrate the advantages of jet propulsion for
commercial aviation. It served as basis for the design of the KC-135 tanker and
the 707 airliner.

The Dash 80 first flew in 1954, less than two years from project launch. Its
US$16 million cost (equivalent to $152 million today) was an enormous risk for
Boeing, which at the time had no committed customers. Only one example was
built, which has been preserved and is currently on public display at the
Udvar-Hazy Center in Virginia.

By the late 1940s two developments encouraged Boeing to begin considering
building a passenger jet. The first was the maiden flight in 1947 of the B-47
Stratojet. The second was the maiden flight in 1949 of the world's first jet
airliner, the de Havilland Comet. Boeing President Bill Allen led a company
delegation to the UK 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. Boeing felt it had mastered the
swept wing and podded engines which it saw as key technologies that would enable
it to improve on the Comet.

In 1950 Boeing tentatively produced a specification for a jet airliner dubbed
the Model 473-60C. The airlines were unconvinced 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 Stratocruiser and Lockheed Constellation.

Boeing was experienced at selling to the military but had not enjoyed the same
success with civil airliners. This market was dominated by Douglas which was
adept at meeting the needs of airlines by refining and developing its range of
propeller-driven aircraft, and in 1950 was marketing the forthcoming DC-7.
Boeing decided the only way to overcome the airlines' suspicion of the jet – and
of itself – was to show them a completed aircraft.

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. Boeing had
studied developments of its existing Model 367 (the KC-97 Stratofreighter)
incorporating swept wings and podded engines; and chose to build the 367-80,
which retained little of the KC-97 except the upper fuselage diameter (and the
possibility of building some of the fuselage with existing tooling). Although
the design was announced publicly as the Model 707, the prototype was referred
to within Boeing simply as the Dash 80 or "-80".

The Dash 80 fuselage was wide enough at 132 inches (335 cm) for five-abreast
seating; two on one side of the aisle and three on the other. The fuselage
diameter for the production KC-135 was widened to 144 inches (366 cm) and Boeing
originally hoped to build the 707 fuselage with that width. 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 148-inch-diameter
(376 cm) fuselage, after C. R. Smith, CEO of American Airlines, told Boeing he
wouldn't buy the 707 unless it was an inch wider than the then-proposed Douglas
DC-8 passenger jet. This decision did not unduly delay the introduction of the
production model since the -80 had been largely hand-built, using little
production tooling.


Role
Prototype transport/airliner

Manufacturer
Boeing

First flight
July 15, 1954

Introduction
1955

Retired
1970

Status
Preserved

Produced
1954

Number built
1

Unit cost

US$16 million (equivalent to $152 million today)

Developed into
Boeing C-135 Stratolifter
Boeing KC-135 Stratotanker
Boeing 707

Other name(s)
Dash 80

Registration
N70700

Owners and operators
Boeing

In service
1954–1969

Preserved at
National Air and Space Museum's Steven F. Udvar-Hazy Center

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. 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.

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.

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.

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."

Specifications (Boeing 367-80)

General characteristics
Crew: Three
Length: 127 ft 10 in (38.96 m)
Wingspan: 129 ft 8 in (39.52 m)
Height: 38 ft 0 in (11.58 m)
Wing area: 2,400 sq ft (220 m2)
Empty weight: 92,120 lb (41,785 kg)
Gross weight: 190,000 lb (86,183 kg)
Powerplant: 4 × Pratt & Whitney JT3 turbojets, 10,000 lbf (44 kN) thrust each

Performance
Maximum speed: 582 mph (937 km/h, 506 kn) at 25,000 ft (7,600 m)
Cruise speed: 550 mph (890 km/h, 480 kn)
Range: 3,530 mi (5,680 km, 3,070 nmi)
Service ceiling: 43,000 ft (13,000 m)
Rate of climb: 2,500 ft/min (13 m/s)




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