The 777X comes in as the successor to the Boeing 777-300ER, featuring a host of advances that bring the aviation industry’s latest innovations to the 777 family. A host of developments allow this jet to be much more efficient, with improved seating capacity, while maintaining a wingspan that allows it to fly from most of the world’s major airports. The cabin is also quieter, yielding a more enjoyable and relaxing passenger experience. Finally, advances on the flight deck will help pilots to complete their work more safely and efficiently.
In this article, discover more about how the Boeing 777X will bring new capabilities to its customers that were not possible for the 777-300ER. Finally, you can learn about the latest updates on when the 777X will take to the skies as the delays seem to be coming to an end.
A Far Older Jet
The most striking difference between the 777X and the 777-300ER is their age. In fact, most other differences stem from the new technology that is available in aviation in the third decade of the 21st century. The first 777-300ER test flight took place in 2003 and the aircraft entered service with Air France a year later, meaning that the technology is now over two decades old.
As a result, much of the technology aboard the 777-300ER is now surpassed by that of its rivals and the other Boeing widebody jets it complements. The first Boeing 787 test flight occurred in December 2009. Airbus’ prominent modern widebody plane is even newer, with its prototype taking off from Toulouse in June 2013.
Meanwhile, the first Boeing 777X took to the skies in January 2020. This extra 13 years of time for new technologies to emerge means that the 777X is a more efficient and higher-performing jet than its predecessor. Furthermore, the market has changed since the 777-300ER emerged. It found success on the market as a middle point between the 787 and 747. Yet, with the 747 being rapidly retired and the A380 approaching the end of its service life, this gap appears to no longer exist.
What Variant Should Be Compared To The 777-300ER?
The most sensible variant to think about when drawing comparisons to the -300ER is the -9. That is because it is larger than the 777-8, a variant built to replace the 777-200LR and compete with the A350-1000. The 777-9 is stretched by three additional seat rows compared to the 777-300ER, giving airlines greater capacity while not reducing the number of gates from which it can be operated.
The table below includes essential specifications for both the Boeing 777-300ER and 777-9 according to Aviator Joe:
|
Characteristics |
-9 |
-300ER |
|---|---|---|
|
Length |
251 ft 8 in (76.72 m) |
242 ft 5 in (73.9 m) |
|
Wingspan |
238 ft 10 in (72.8 m) |
212 ft 7 in (65.8 m) |
|
Thrust per engine |
105,000 lbf (467 kN) |
115,300 lbf (513 kN) |
|
Maximum takeoff weight |
775,000 lbs (351,500 kg) |
775,000 lbs (351,500 kg) |
|
Range |
7,290 nautical miles (13,500 km) |
7,880 nautical miles (14,600 km) |
|
Capacity |
426 passengers |
365 passengers |
The benefits brought by the 777-9 compared with the -300ER will not be cheap. Avitas, an aviation valuation specialist, stated a list price of $426 million, with discounts for bulk orders reaching up to $200 million in 2018, according to Seattle Times reporting.
Wing Adaptions
A substantial advance made by the 777X’s design over past 777 variants is the wing design. Older 777 variants were often considered to be too small for what the 777 was trying to achieve. This limited the lift produced, resulting in a lower cruising altitude. Modern aircraft, like the A350, A330ceo and 787 can regularly exceed 40,000ft, while older variants of the 777 peak at 35,000 or 38,000 ft when flying with a full load.
The maximum cruising altitude makes a substantial distance when flying over the long ranges that the 777X will be able to achieve. Due to the reduced air resistance at altitude, the less fuel that is used the higher an aircraft goes. As a result, a manufacturer can promise reduced operating costs and higher profits.
Boeing has expanded the wingspan by over 20 ft with the 777X. It has achieved this with folding wingtips. These devices grant a broader wingspan while ensuring the jet can still operate from gates that are compatible with older 777 variants. The innovation perfectly balances consistency and technological advancements.
Better Engines
The 777X also has better engines than the -300ER, further reducing fuel burn and operating costs per seat. Whereas the -300 used the General Electric GE90, the 777x family will use the General Electric GE9X engine. The GE90 entered service with British Airways in 1995, and the engine’s thrust ratings vary from 81,000 lbf to 115,000 lbf (360 to 510 kN). It was the largest jet engine in commercial aviation and will be surpassed by the GE9X, boasting a 6-inch (15 cm) broader fan diameter. Its 134-inch (340 cm) fan diameter is famous for being almost the same width as a Boeing 737’s fuselage.
The GE9X will also feature a higher bypass and compression ratio, and use more advanced materials. The engine produces a similar amount of power at 110,000 lbf during takeoff and 134,300 lbf maximum thrust, but its improved design will lead to more efficient operation that reduces noise and air pollution.
The table below includes key specifications for the GE9X engine according to the Federal Aviation Administration type certificate data sheet on it:
|
Fan diameter |
134 in (3,404 mm) |
|
Blades |
16 |
|
Length |
224.0 in (5,690 mm) |
|
Bypass ration |
10:1 |
|
Overall pressure ratio |
60:1 |
|
Weight |
21,230 lb (9,630 kg) |
|
Thrust to weight ratio |
5.2 |
|
Maximum RPM |
Low pass: 2,355, high pass: 9,561 |
The Executive Vice President and Chief Commercial Officer of GE Aerospace, John Slattery, commented on how he believes the engine will revolutionize the aviation sector: “It takes the world’s best talent in jet propulsion to create a game-changing product like the GE9X engine. There is no substitute that can achieve the combination of size power and fuel efficiency of the GE9X. This engine will deliver unsurpassed value and reliability to our airline customers.” The combination of engine and aerodynamic improvements has led to estimates that the 777X will be 10-15% more fuel efficient.
What 777X Variants Will Be Even More Different From The 777-300ER?
One way that other 777Xs will differ from the -300ER is with even longer variants, such as the proposed 777-10. This would add another four rows to the 777-9, raising the capacity to 450 passengers. The length would reach 263 feet (80 m), 12 ft (3.7 m) more than the 777-9.
The jet would compete against Airbus’s proposed A350-1000 stretched variant, adding 45 seats and 13 ft (4 m) in length. The stretched A350-1000 may require an 11-ton increase in maximum takeoff weight and 3% more thrust, although the thrust increase is already considered within the capabilities of the Rolls-Royce Trent XWB-97. However, initial consideration of this idea was shelved in 2017 due to lack of market demand, and Airbus is considering waiting until a new engine generation before re-launching the stretch concept.
The other different variant to consider is the Boeing Business Jet 777X, which differs significantly from the -300ER in its non-commercial use. Boeing launched this concept at the Middle East Business Aviation Association Show in December 2018. There are two variants of the BBJ 777X. The smaller is the BBJ 777-8, while the larger is the BBJ 777-9.
When Will We See The 777X Take To The Skies?
Now that we know the main differences between the 777-300 and 777X, the question remaining is when the jet will finally enter service following countless delays. Simple Flying’s Dillon Shah has reported on Boeing’s confidence at the 2025 Paris Air Show that it would begin 777X deliveries in 2026. Boeing’s Customer Leader for 777Xs and Freighters, Justin Hale, said he is “very confident that the airplane can enter service in 2026.”
Not all of Boeing’s customers are confident that the delivery will be met. Emirates, which has been frustrated by the lack of progress, has shared that they don’t think they will receive the aircraft until 2027 or later. Hale also responded to such queries, saying, “Emirates is not our first delivery airplane [ie inaugural customer], so when they talk about their airplanes coming in 2027, they’re not at the front of the delivery stream and that was their choice of positioning. I think it’s very important to be able to sit down with them and we do, regularly, with all of our customers, and talk about the progress we are making and the status of our certification work.”
Boeing currently has 551 orders awaiting delivery for the 777X across the -8, -9, and 8F variants. Until these orders begin to be filled, no airlines or passengers can benefit from the host of advancements made by the jet.
