• 787-8 Dreamliner
    Boeing
    Stock Code:
    BA
    Date Founded:
    1916-07-15
    CEO:
    Dave Calhoun
    Headquarters Location:
    Chicago, USA
    Key Product Lines:
    Boeing 737, Boeing 747, Boeing 757, Boeing 767, Boeing 777, Boeing 787
    Business Type:
    Planemaker

Summary

  • Boeing's 7J7 was intended to be a fuel-efficient successor to the 727 but never made it past the drawing board.
  • The 7J7 design included advanced technology and propfan engines to reduce fuel consumption and increase efficiency.
  • Boeing's indecision over the size and engine selection for the 7J7, as well as the success of the 737, led to the project's cancelation.

While US aerospace giant Boeing may be best known for its numerous success stories, the company also designed its fair share of aircraft that never made it into the skies. One such aircraft is the rather bizarre propfan-powered Boeing 7J7, a radical new concept that sought to reduce fuel consumption drastically.

The plane was slated to enter the market as a successor to the Boeing 727 and was supposed to carry up to 150 passengers. The idea emerged late in the 1980s, and the manufacturer sought to have the aircraft flying by 1992.

In essence, the manufacturer planned to capitalize on fuel-efficient technology to develop a conventional aircraft with nonconventional propulsion. Unfortunately, the idea never made it off of the drawing board. In this article, we will take a closer look at the unrealized potential of this program.

The idea of the 7J7

The Boeing 7J7 was the manufacturer's attempt to replace the Boeing 727. Initially, the 757 had been expected to fill this role, but sales were sluggish at the time.

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Over 1,000 examples of the type were produced.

As airline deregulation began to take hold, it became apparent not all airlines wanted a larger replacement plane. Instead, they would prefer something smaller, more efficient, and could be used to add frequencies on short routes.

A Delta Air Lines Boeing 757-300 Departing From Hartsfield–Jackson Atlanta International Airport.
Photo: Markus Mainka | Shutterstock

One of Boeing's most significant challenges was an emergent gap in its commercial offerings. The 737-100's capacity topped at 118, and the 757 could not carry fewer than 200. If Boeing could find a way to bridge this roughly 80-seat gap in its lineup, sales would surely skyrocket. As a result, the planemaker revealed this unique concept in 1985 at the Paris Air Show.

Initially, there was a lot of interest in the project, particularly in the US, Europe, and Japan. Notably, the airplane's name even gave a nod to Japan, having been initially called the 7-7 but changed to the 7J7 to reflect Japanese confidence in the project. Boeing started taking orders for the model in 1988 and intended to begin delivering the type in 1992, according to The Air Current.

The 7J7 design

Being's concept for the plane that would never fly with commercial airlines came in two flavors. The 7J7-100 would seat 150 passengers, while the smaller 7J7-110 would seat between 100 and 150. According to the Northwest Airlines History Association, it would be equipped with the latest technology, like a glass cockpit, a fly-by-wire flight control system, an integrated avionics suite, and two UDF rear-mounted propfan engines.

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A propfan engine is a kind of cross between a turbofan and a turboprop but with unique distinctions from both. With rotors mounted at the rear, the engines can generate additional thrust while taking in significantly less fuel, increasing operational efficiency.

This design was conceived to deliver savings on fuel consumption and was expected to be more efficient than any other passenger aircraft flying at the time. Boeing said that the propfan technology would account for most of the fuel saved but noted that other aerodynamic elements would also help.

Boeing also planned to use aluminum-lithium composites in the plane, which would help reduce weight. Its wings would be made of the composite material, but it was also more expensive than the aluminum alloys that most planes had. In addition to that, Boeing wanted to use carbon fiber to design other parts of the airplane's structure.

Why Boeing never built the 7J7

So why did Boeing never deliver on its promise for the 7J7? The first signs of trouble came when there were some confusing messages about the engine selection for the aircraft. It became evident that it was planning to offer the smaller aircraft with turbofans but the larger with ducted engines.

Eventually, Boeing canceled plans for the smaller variant, planning instead to expand its 737 range. Boeing's inability to commit to a single design made investors wary, shaking their support for this relatively ambitious program.

Despite this, Boeing had interest from two major airlines: British Airways and SAS. But before any deals could be signed and sealed, the announcement came that certification of the plane would be later than expected.

Now, it would be 1993 before the plane was expected to be approved, with Boeing citing indecision over the size of the aircraft to be produced initially. BA and SAS wanted a smaller aircraft with around 140 seats, while American Airlines had indicated interest in ordering a version featuring a capacity of 170.

The problem with this was that, at 170 seats, the selected engines could not power a stretch of that size. Enthusiasm for the project began to peter out as Boeing steered American Airlines towards its 757 and began work on larger versions of the 737. Rumor has it that the project was killed off from the inside, as Boeing executives believed the future lay in producing more variants of the 737. Turns out, they were right.

But the 7J7 was an interesting lesson learned for Boeing. It failed to consult with airlines properly in the planning stages, which is something it rectified in future aircraft projects. Much of the research and development fed through to future airliners for the US planemaker.

However, Boeing did not come out of this program with nothing. The friends it had made in Japan eventually led to some strong influences on the development of the 787, among the manufacturer's most successful projects to date.

Would you have flown on the Boeing 7J7? Do you like the 7J7 or 757? Let us know in the comments!