The Military Prototype that Launched the Civilian Jet Age

By Patrick J. Walsh

From a single voice in a corporate boardroom to the screech of jet engines powering a huge airframe into the western sky, Boeing’s early 1950s development of the 367-80 prototype created a distinctive soundtrack for one of the great industrial success stories in American history. Known within Boeing simply as the “Dash 80,” the 367-80 was the culmination of 5 years of corporate self-evaluation. From concept to finished airframe, it reflected a clear-eyed analysis of the state of the market for military and civilian aircraft in the years following World War II.

The prototype was largely custom built, with many of its components hand-tooled. It ultimately would serve as the basis for both the Boeing C-135 Stratolifter transport (which was in turn developed as the KC-135 Stratotanker aerial refueling aircraft) and the Boeing 707 commercial airliner.


Military Expertise

Boeing had secured a lofty reputation as the producer of large bombers before and during World War II. The company’s B-17 Flying Fortress and B-29 Superfortress played a legendary role in winning the war.

The design expertise at the heart of these capable warfighters was a key asset in the firm’s attempts to adapt to the changing priorities of the peacetime military establishment. Boeing’s early successes of the post-World War II era included the jet-powered B-47 Stratojet and B-52 Stratofortress strategic bombers, as well as the KC-97 Stratofreighter tanker.

Although the KC-97 was itself powered by four piston engines (World War II era Pratt & Whitney R-4360s), it was able to perform aerial refueling of jet aircraft. This made it an important part of the U.S. Air Force inventory from 1950, until it was supplanted by the KC-135, beginning in 1957.

Commercial Limitations

Even as the rapid evolution of jet-powered aircraft began to transform the nation’s military air fleet, the introduction of this promising technology into the lucrative civilian jet airliner market was delayed due to the skepticism of airline executives. Although jets could carry more passengers per flight more quickly, making both short- and long-range air travel more attractive to customers, the substantial investment involved in adapting the commercial airline industry to the needs of large passenger jets seemed an overwhelming obstacle for many carriers.

For Boeing, the prospect of selling a jet airliner was particularly challenging. The manufacturer faced stiff competition in the civilian market from the Douglas Aircraft Company, which already was well established as the primary producer of turboprop commercial airliners. (Douglas ultimately would become a part of its long-time competitor as a result of the 1997 merger of Boeing and McDonnell Douglas.)


A Novel Solution

Boeing was typecast as a producer of large, expensive, state-of-the-art military aircraft, and was virtually alone in its conviction that the “Jet Age” would arrive sooner rather than later for the civilian market. The executive leadership of each of its primary competitors — including Douglas, Lockheed, and Convair — was convinced that any transition to a pure jet airliner would be preceded by a more gradual transformation from piston to propjet.

In May 1952, William Allen, President of Boeing, met with the company’s board of directors. During the course of his presentation, Allen convinced the board to commit $15 million (of an eventual $16 million total) to the development of a prototype aircraft that would demonstrate the viability of both a jet-powered military transport, which could be outfitted as a replacement for the KC-97 tanker, and a commercially viable pure jet airliner.

The project enabled Boeing to take advantage of a federal tax rule that allowed large corporations to reinvest a portion of revenues in research and development efforts. This was in lieu of a steep tax on excess profit that had been enacted in the post-war period.(In large part due to the success of its B-47 and B-52 bombers, Boeing’s effective tax rate at the time was 82 percent.).

Positioning the project as the prototype for a military aircraft, as well as a civilian airliner, also allowed the sharing of tooling and parts between each of the resulting airframes. This substantially reduced production costs and helped make each aircraft financially viable in its respective market.

Nevertheless, Boeing’s financial commitment to its dual-purpose prototype represented a major risk for the company, as it had no committed customer, military or civilian, when the board agreed to proceed with the development of the Dash 80.The decision would seem an even greater gamble when the U.S. Air Force Strategic Air Command (SAC) announced in 1955 that it had chosen Lockheed as the winner of its competition to produce the first jet-powered military aerial refueler.



Fortunately for Boeing, the Dash 80 had an early start in developing what would become the KC-135. While waiting for the Lockheed design to reach production, the U.S. Air Force placed an order for the Boeing tanker as a stopgap. Ultimately, the Air Force canceled its arrangements with Lockheed and adopted the KC-135 for the long term.

The military contract enabled Boeing to thoroughly test its prototype as part of its development. This also ensured that the civilian version, the 707, would be production-ready as soon as commercial carriers were ready to buy.

During its maiden flight, on July 15, 1954 in Seattle, Boeing test pilot Alvin “Tex” Johnston put the large aircraft through several barrel rolls. This demonstration left the large crowd of onlookers, including many prospective 707 buyers, with an astonishing and enduring first impression of the Dash 80’s power and maneuverability.

Boeing received its first order for the civilian version of its new jet on October 13, 1955, when Pan American World Airways agreed to purchase twenty 707s.(The airline also committed to the purchase of twenty-five Douglas DC-8s, ensuring a fierce competition between the manufacturers for years to come.) By the end of the year, five other major carriers had placed orders for the 707.

The iconic airliner quickly became synonymous with depictions of jet air travel in popular culture, and led to Boeing being acclaimed as the company most responsible for launching the Jet Age of passenger air travel in the United States. At the same time, the KC-135 furthered Boeing’s hegemony in the market for military aircraft. The model remains in service with its original operator, the U.S. Air Force, 60 years after its introduction. During its production run, from 1955 to 1965, Boeing built 803 Stratotankers.

The Dash 80 prototype that was at the center of each of these historic aircraft was ultimately recognized by the Smithsonian Institute as “one of the 12 most significant aircraft of all time.” It has been restored as an exhibit of the Smithsonian’s National Air and Space Museum.


Image #1 -Production and testing of Boeing’s KC-135 Stratotanker military refueling aircraft and civilian 707 airliner were simplified by the fact that the two aircraft were developed from the same prototype. This KC-135, seen at NASA’s Dryden Flight Research Center in 1958, was used in tests that helped shape new approach procedure guidelines for the Boeing 707. (National Aeronautics and Space Administration)

Image #2 – As the launch customer for the Boeing 707 airliner, Pan American World Airways became the first U.S. carrier to routinely offer passenger jet service for transcontinental and intercontinental air travel. Pan Am made its first scheduled jet flight on October 26, 1958, from New York’s Idlewild Airport to Le Bourget Airport in Paris — “connecting New York and Paris in seven hours.”(U.S. National Archives and Records Administration)

Image #3 – The Boeing 367-80 “Dash 80” prototype is shown on the flight line at Davis-Monthan Air Force Base in Arizona. Boeing donated the Dash 80 to the Smithsonian Institution’s National Air and Space Museum in May 1972, and the historic aircraft was stored at the Davis-Monthan Boneyard until 1990, when it was restored for Boeing’s 75th anniversary celebration the following year. It is currently on display at the Smithsonian’s Udvar-Hazy Center at Dulles International Airport in Virginia. (U.S. National Archives and Records Administration)

Image #4 – Although airline executives and most aircraft manufacturers foresaw little market demand for a civilian jet airliner at the time of Boeing’s May 1952 decision to build the $16 million prototype, the iconic, swept-wing, four-engine Dash 80 became the aircraft most commonly associated with the advent of the Jet Age in the United States. (U.S. National Archives and Records Administration)


Boeing, “Model 367-80 Historical Snapshot.”

Andrew R. Boone. “Boeing’s Jet Stratoliner,” Popular Science, July 1954.

Charles D. Bright. The Jet Makers: The Aerospace Industry from 1945 to 1972. Lawrence, KS: University Press of Kansas, 1986.

Michael Lombardi, “Start of a Proud Mission,” Boeing Frontiers, July 2006.

Mike May, “Gas Stations in the Sky,” American Heritage of Invention and Technology, Spring 2004.

MaryCate Most, “An Anniversary for Dash 80.” National Air and Space Museum, July 2016.

Steven A. Ruffin. Aviation’s Most Wanted: The Top 10 book of Winged Wonders, Lucky Landings and Other Aerial Oddities. Washington, DC: Potomac Books, 2005.

R.G. Thompson. “Dash 80: The story of the prototype 707,”Air & Space, April 1987.