How Boeing Almost Built A 777 With Three Engines

One of the most successful aircraft in the history of aviation, the B777, still fights its corner after 25 years. But, in development, the revolutionary plane was slated to have three, not two, engines.

British Airways B777 on runway
A triple-jet B777 may not have been as popular as the twin-jet variant. Photo: Nick Morrish/British Airways

The B777 and the B747 are two of Boeing’s historic successes. The introduction of the 747 in 1969 was a game-changer. The cost of mass travel was reduced, the world’s haulage processes were invigorated, and airports worldwide grew exponentially.

The 777, which flew commercially for the first time in 1995 with United, brought similar sweeping changes to the industry. It heralded a new era of twin-engine flight: quieter, more efficient, more economical and of a greater range (B777-200LR).


It may even have sounded the death knell of the 747.


Of the 777, Boeing has since received more orders than of any other wide-body airliner. By August of this year, more than 60 customers had placed orders for 2,049 aircraft of all variants. 1,609 had been delivered, according to Boeing’s sales summary.

But the long-haul mainstay may not have enjoyed the same popularity from the outset. Had Boeing given way to a contingent of developers who at the time considered a triple-jet aircraft to be the order of the day, the 777 would no longer be flying.


Almost a tri-jet

The B777 was in its early days to be a tri-jet. At the time, the widely-regarded theory was that more engines gave an aircraft a better chance of remaining airborne. That steered developers towards the production of something akin to a larger version of the Lockheed TriStar.

BA TriStar on taxiway
The TriStar was considered one of the safest planes ever made. Photo: Michel Gilliand via Wikimedia

Furthermore, aviation authorities had imposed regulations limiting the routes and distance a twin-engine aircraft was permitted to fly. Early twin-engine wide-body jets such as the Airbus A300B2 were restricted to medium-haul ops, writes Business Insider.

Thus it looked likely a tri-jet 777 was on the cards. Flight International even reported in 1978 a plan by Boeing to introduce the “trijet 777”.

However, Boeing also knew the tri-jet would be an unpopular and illogical choice of configuration. In light of the projected engine power of new engines, the airplane may feasibly cover the same distances as the 747.

Changes of regs

Nothing had been decided on the future of the type by the time ETOPS regulations governing twin-jet operations were lifted in the late 1980s. But that lifting of sanctions meant Boeing’s variants – the 757 and 767 – could begin flying long-haul routes beside the pre-existing 747.

Boeing stepped up its efforts to devise an aircraft that could fill the void between the 747 and 767. One that had a longer and wider fuselage than the 767 and a fully flexible interior. It would also be one capable of an intercontinental range, but with an operating cost lower than that of any 767 stretch.

In the end, the company opted for the twin-engine configuration. In view of projected engine developments and with the promise of reduced costs, the 777 was made.

The jet’s high bypass turbofan engines built by Rolls-Royce, Pratt & Whitney, and GE are the largest engines ever installed on an airliner, according to Business Insider.

Emirates B777 in flight
The B777-300ER is the most popular variant of the type. Photo: Emirates

From then until now

Boeing’s widebody Goliath took to the skies on June 12th, 1994. A year later, the 777-200 entered service with United Airlines. The aircraft was capable of carrying between 305 and 440 passengers 8,270 miles.

The most recent type, the 777-300ER, can carry 396 passengers 7,370 nautical miles. As of August 2019, according to Boeing, 45 different airlines have received a total of 810 -300ERs. The company possessed just 34 unfilled orders.

Despite dramatic changes to the industry in recent years, the success of Boeing’s type appears to be assured.


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Paul Thorne

However Boeing got their hands on a tri jet which could have been tweaked but decided to dump it.


Would you have kept the MD-11 around much longer?

In-Frequent Flyer

Well, there was the 727, but that stopped production long ago.


The DC-10’s made me a little nervous, but I loved flying on the L1011s. They sounded like a creaky old truck while taxiing, but flew like a stallion in the air.
I would much rather be on a tri or quad-jet crossing the Pacific than the “Engines Turn Or Passengers Swim” (ETOPS) twin engine.

In-Frequent Flyer

Good luck with that. Eventually all Quad jets will stop flying outside of freighter operations and twins will rule the sky for carrying passengers.

Paul Proctor

If you examine the flight completion and turnback records carefully you’ll see that twin jets have the better record. Why? Quads have twice as much to go wrong. I did an AvWeek story on the subject in the 1990s regarding North Atlantic routes, really angered Airbus, which was flogging the A-340 and A-380 at the time.

In-Frequent Flyer

They were pretty pissed about the 777 practically making the A340 almost obsolete because it automatically had a high ETOPS rating. I mean, if I spent years making a quad jet specifically meant to bypass this restriction, only to have a competitor come and make a jet that was not only more fuel efficient, but carried similar amount of PAX, I’d be pissed too.


The A340-300 is essentially a quad-version of the A330-300. Parts and systems commonality is higher than 90 percent — reduced to about 50 percent with the A340-500/-600. In contrast, the “grandfathered” 777-9X has less than 40 percent parts and systems commonality with the 777-300ER. So, from a production point of view, it didn’t matter one iota to Airbus whether or not an A330-300 or A340-300 were rolling off the assembly line. Interestingly, through September 2019, Boeing has received 2049 orders for the 777/777X. In comparison, Airbus has received 1751 orders for the A330/A330neo and 377 orders (total number of deliveries)… Read more »


@Paul Proctor Would you agree that your comment in this thread : … would suggest that you may not be entirely unbiased when it comes to anything related to Airbus? It’s interesting to note, though, that you didn’t respond to my comment in that thread. – Now, may I suggest that you read this article by Björn Fehrm of Leeham News and Analysis: Quote: “The two- and four-engined long range aircraft that have been available in the market are all of different size and vintage. To make comparisons worth the name we need to equalize such differences as… Read more »

Paul Proctor

May I suggest you look up that AvWeek story yourself. It was under my byline. I think it was comparing 767s to then-current quads and trijets flying across the pond. Airbus or a proxy complained to my editor, Dave North, and I told him it was based on OAG schedules and data between such-and-such dates. Airbus was welcome to make the same comparison and I, or my Paris bureau chief, would write up their reactions. Never heard a word. Despite aircraft vintage, you can still compare ultimate schedule performance on a route or set of routes over a set period… Read more »


@Paul Proctor First, you said that you did an AW&ST story on the subject in the 1990s regarding North Atlantic routes and that it really ANGERED Airbus; then, you said that Airbus was welcome to make the same comparison and that you, or your my Paris bureau chief, would write up their reactions, but that you never heard a word. Hmm, the two accounts don’t seem to square up, do they? Now, the ETOPS – formerly: Extended-range Twin-engine Operational Performance Standards, changed to “Extended Operations” — rules where put in place on 16-Jan-2007 for Trijets and Quads when operating more… Read more »


This article should be entitled “How Boeing Almost Built A 767 With Three Engines.” The B767, which was developed simultaneously with the B757 in the late 1970’s, originally called for both a two engine and three engine version. I worked on this project. The three engine version was informally referred to as the “777” among those in the development community. Due to changing ETOPS regulations, the three engine “777” version was scrapped prior to production. Also eliminated was the requirement for a flight engineer, resulting in a oversized cockpit with unused space towards the rear where the Flight Engineer console… Read more »

john ballekom

always loved the 767, but only if it had 7 abreast economy. xx xxx xx every seat seems to have something going for it, cabin always felt just right, 7 seats across and 2 aisles, rather than 6 across and one aisle

Paul Proctor

An entire story based on one reference to a (in the end incorrect) Flight International comment. I suggest you look at past issues of Boeing Frontiers magazine, available on the http://www.boeing site and Internet. There’s a great story and photos on past Boeing jetliner development projects, including the “Hunchback of Mukilteo.”


Correct, Paul. I worked on a 3 engine 767 in the 1970’s which was tentatively designated “777.” When the 3 engine 767 was dropped, the 777 designator was recycled, and used for the brand new aircraft that we now know as the B777. This aircraft was *never* envisioned as a 3 engine aircraft.

By the way, there are two different Karls commenting on this thread. I’m the slightly brighter one.


No engines > 100k lbs were available that’s why they looked a t a 2.5 engined 777X..
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