The Story Of The Boeing 707: The Jet Age Aircraft Of Choice

We are feeling the effect of the 707’s launch every time we sit on a Boeing jet today. Despite flying for the first time over six decades ago, the plane is still leaving a legacy. With this impact in mind, here’s a look at the story of the legend.

Boeing 707 Headed for Paint Hangar
The Boeing 707 rolling off the assembly line in 1957. Photo: Getty Images

A new beginning

Following the fall of World War II, the jet engine started to create a buzz in commercial aviation. The United Kingdom pioneered commercial jet service with the de Havilland Comet, but there were well-publicized teething problems with the type, which led to tragic incidents. With the grounding of this plane, the initial mania related to jet aircraft vanished.

Across the pond, United States-based manufacturers were also keen to diversify and expand in the new era. For instance, Boeing’s leadership was interested in ramping up efforts in commercial aircraft and exploring new possibilities with spacecraft and missiles, which were aspects hotting up in the post-war climate.

Boeing was already well familiar with jet aircraft, thanks to its development of the first large swept-wing jet in the world, the B-47. Subsequently, airlines began asking if Boeing could offer a commercial jet solution. Notably, Pan Am requested such a move.

The manufacturer looked into converting the 367 Stratotanker propeller plane, more well known as the KC-97, into a jet-powered tanker. Numerous variations were developed, but a variant going by the name 367-80 was chosen. This aircraft would be dubbed the Dash 80.

Boeing 367-80 During In-Flight Engine Testing
Earlier units were initially equipped with turbojet engines, but the main setup for the Boeing 707 family included four Pratt & Whitney JT3D turbofans. Photo: Getty Images

All in a name

Avgeeks often ponder over the inauguration of the 7-7 numbering system. This method traces its routes back to the launch of the 707, with several commenters offering their own theory as to why Boeing chose this system.

With Boeing’s diversification, transports were split into different categories. 400 continued to be reserved for aircraft, and 500 would be earmarked for turbine engines. Meanwhile, 600 would be used for rockets and missiles, while 700 was reserved for jets.

“People who lean toward math and engineering are certain that 707 was chosen because it is the sine of the angle of wing sweep on a 707. It’s not, since the wing sweep is 35 degrees and not 45. However, more people lean toward superstition and feel that the positive connotation of the number seven was the reason it was selected,” Boeing Frontiers shares.

“The truth is a bit more mundane. Boeing has assigned sequential model numbers to its designs for decades, as have most aircraft manufacturers. Boeing commercial aircraft use their model number as their popular name: Model 40, Model 80, Model 247, Model 307 Stratoliner and Model 377 Stratocruiser.”

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Full faith

Despite the struggles across the Atlantic, Boeing president William Allen and his colleagues firmly believed in the future of jet aircraft. Thus, the company took the leap of faith and financed the Dash 80 prototype’s advancement. Overall, the board committed $16 million ($157.9 million today) of the company’s own money.

The mission was to introduce a tanker/transport and a commercial aircraft. Both of these offsprings would be jets. Therefore, they would naturally fall into the 700 category.

“The model number system called for a number in the 700s to identify the two new planes. The marketing department decided that “Model 700” did not have a good ring to it for the company’s first commercial jet,” Boeing Frontiers adds.

“So they decided to skip ahead to Model 707 because that reiteration seemed a bit catchier. Following that pattern, the other offspring of the Dash 80, the Air Force tanker, was given the model number 717. Since it was an Air Force plane, it was also given a military designation of KC-135.”

Pan American 707-120
The original production 707-120 had a range of up to 3,000 NM (5,600 km) and had a cruise speed between 484-540 kn / (897-1000 km/h). Photo: Getty Images

Plenty of space

Both the military KC-135 and passenger 707 were born from the Dash 80 prototype. Operators were keen to have the 707’s fuselage four inches wider than the KC-135. Therefore, with its notable width and 100-foot (30.5-meter) length, it held the largest passenger cabin in the world. With over 100 windows and doors on the left, front, and rear, carriers had the freedom to configure seats to their requirements.

Boeing also notes that the look of the exterior of the 707 was very close to that of the DC-8. However, its own aircraft had more sweepback. This factor enabled the plane to travel faster by approximately 20 mph (32 kph).

Passengers Inside 707 Stratoliner Mock-up
Passengers would have noticed features that are now mainstays, such as call buttons, reading lights, and emergency oxygen masks. Photo: Getty Images

So it begins

With the program well underway, the first production 707-120  conducted its first flight on December 20th, 1957. The following September, the plane was FFA certified, and the type was introduced on October 26th, 1958, with Pan American.

This entry to service caused an unprecedented impact on the aviation industry. Within just a few years, air took over rail and sea travel with the assistance of this plane. Over the years, the likes of Alaska Airlines, American Airlines, Braniff International Airways, Continental Airlines, Northeast Airlines, Northwest Airlines, TWA, and Western Airlines would expand with the 707. Importantly, it also outpaced its rival DC-8 when it came to sales.

It’s important to note the achievement of Boeing to overcome the challenges in the industry when it came to jet aircraft. The firm managed to shift the public view of the aircraft with a press campaign highlighting the strong pressurized cabin of the plane that could hold its structure together following significant impact.

Boeing wasn’t complacent either. It continued to transition with requirements, such as with the development of a unique long-range model for Qantas and a high-altitude edition for Braniff.

John Travolta's Boeing 707 At Sydney Airport
Actor John Travolta took on a former Qantas Boeing 707. Photo: Getty Images

The 720 was another adaptation. The 707 was given this designation when it was modified to handle short- to medium-range operations and for utilization on shorter runways.

Looking back

Altogether, the 707 was a resounding success. 856 units were built between 1956 and 1978, and 154 720s were produced between 1958 and 1967, giving a grand total of 1010 aircraft.

Boeing 707 Interior
The 707 is synonymous with the commercial jet age. Photo: Getty Images

Boeing managed to succeed with its own ambitions while changing the face of the aviation industry for decades to come with the introduction of the 707. As the company puts it, every commercial jet that it has ever offered has been a development of this plane.

What are your thoughts about the Boeing 707? What do you make of the aircraft’s journey over the years? Let us know what you think of the plane and its operations in the comment section.

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