The Unreleased 2 Engine Boeing 747

During an era of emphasis on increasing efficiency in widebody aircraft, there has often been dialogue surrounding a new 747 variant.

There’s been talk of a potential twin-engine version in what is championed as the queen of the skies and a quad-engined jet.

Does a twin-engine 747 have any legs behind it, what are its complications, why wasn’t it launched, and did it end up being the right decision?

The Many Boeing 747 Variants

Most commercial aircraft programs will have several studied variants but won’t get the planemaker’s firm go-ahead to proceed with a formal launch.

The 747, which had a production stint lasting over half a century, was a prime example of a program that experienced many variants studied that never entirely made the drawing board.

Each potential variant was seemingly more outlandish than the other. From the study of the trijet 747s to full double-decker versions to combat emerging competition from Airbus, each had its uniqueness, which was attempted to be brought to market but ultimately failed.

However, it would be discussed internally across the industry concerning a possible twin-engine variant for the 747 that amassed much interest.

What Was The Twin Engine Concept?

Unlike the trijet concept and even a full double-decker model, Boeing never formally confirmed a twin-engine 747 as a study; rather, it was a proposed aircraft within the industry as a potential means of making capacity flying more efficient.

In essence, the prospective plane would’ve looked to continue with the 747’s first iterations, which they were known and loved for, but adopt a more efficient power source in the engines, also reducing the amount on the wing by half.

If released, the jet would have sought to bring efficiency to the widebody platform. However, this never made much sense when further analysis was made on the possible launch of the jet.

For some, the twin-engine concept on the 747 was never released, but for good reason; that good reason is that it exists nowadays in the 777.

A high-capacity jet, not intended as a like-for-like replacement to the queen of the skies but very much a new-generation twin-engine plane aimed for long-haul flying with a larger capacity.

Why Didn’t The Aircraft Release?

Despite not being studied by Boeing, a twin-engine 747 still attracted a fair share of interest from enthusiasts and others who studied how Boeing could reclaim its market share in the widebody space.

However, a twin-engine 747 would’ve required a colossal amount of investment and radical design changes by the planemaker to make this work.

Thanks to the significant leaps achieved in engine thrusts and power, slotting two engines onto the 747 body would theoretically work. However, it just about ends there, with many other requirements needing to be met.

Adding the two engines and dealing with varied power changes structurally would require adjustments, especially with a whole new wing design, which would cost a significant amount of funds alongside many other exterior investments.

The wing, part of the broader airframe, is not made to have the twin-engine nature applied to this aircraft. The 747 was built with four engines. While, at times, a trijet option was studied, this would follow the theme with the MD-11 and DC-10.

Other aspects, such as weight, would need to be considered. This would also ignore factors such as safety during the unlikely event of a full-scale engine failure.

If Boeing so desperately believed customers needed a more efficient high-capacity model, it could always move ahead with its 777-10. This is a prospective variant in the 777X program, which has achieved technical feasibility but hasn’t been launched.

Who Would This Boeing 747 Variant Be For?

Other complex challenges existed, such as finding a market for twin-engine aircraft such as the 747 in an age when airlines were moving away from these planes.

Accounting for the investment to make all of this possible, and even the tough process of learning with engine manufacturers, there would be little to no market visible for the jet.

The uncertified but launched 777X jet will help replace the 747 for some customers and is seen as the future. Arguably, many decades ago, even the first iteration in the 777 series was seen by some companies as the more efficient answer to the 747.

The 747 doesn’t have a radically different capacity from the 777. By analysing these metrics alone and other key areas, moving ahead with a re-engine of the 747, excluding all the other complexities, wouldn’t be a worthwhile investment for the lack of a customer base.

A New Era For Boeing

In the mid-2020s, a new era arose for the American planemaker, which has seen it move away from traditional quad-engined jets, which have dominated the industry for so long.

Now, flexibility and efficiency are paramount, and even if this causes a loss in capacity on some of your largest widebodies, airlines are willing to make the decision.

The development of the 787, acting as a new clean sheet, was the planemaker’s first genuine endeavour into the next generation of commercial widebodies and, from a metrics aspect, has ticked all the boxes for airlines.

The launch of the 777X is the next endeavour unfolding at the American planemaker. While there have been challenges in getting this plane to market, it presents fresh opportunities for airline customers seeking to renew their network.

Sometimes, the 777X has been selected as the 747 replacement, such as at British Airways. While it may not be the most adequate like-for-like replacement, its performance metrics naturally crush the 747 through continued advancements.