Owner of the world’s largest airliner fleet, 
United Airlines (UA) boasts 22 examples of Boeing’s enormous 777-300ER (extended range) widebody jet. The long-haul twinjet is the highest-capacity aircraft in the 1,055-plane-strong fleet. It is also one of the longest-range jetliners that United currently flies, with all of its routes being transcontinental or transoceanic.
Even though the 
Boeing 787 Dreamliner is a newer design, the United 777-300ERs are only one year older on average, according to Planespotters.net data. Despite being a previous generation, the aircraft is still one of the most luxurious and comfortable ways to travel by air in 2025.
The huge jetliner accommodates a large number of Premium cabin products including United Polaris Business Class, United Premium Plus, and United Premium Economy. While the airline will likely bring other new widebodies into service, like the Airbus A350, these well-appointed and exceptionally reliable big Boeings are expected to remain in service for many years.
The Boeing 777-300ER managed to outlast even the “Queen of the Skies,” the 747. The jet’s large cabin, high reliability, low maintenance, and much lower operating costs saw it become the new flagship of the United Fleet. United retired the last 747 in 2017, 2 years before the newest UA 777-300ER was delivered.
The uncertain economics of the Coronavirus Pandemic travel lockdown for airlines cemented the decision to abandon four-engine airliners in favor of two-engine models. Although a handful of airlines around the world have continued to operate Boeing 747 or Airbus A380 and A340 quadjets, the majority have already been phased out.
Some may see the 777 as a step-down in prestige, and while there is certainly lower raw capacity, the overall operational results are much better with an aircraft like the -300ER. It isn’t just the lower gas bill or the shop fees, but also the fact that the best cabin products can still be outfitted on a big twinjet.
While many reminisce about the golden era when the 747 was the flagship of many airlines, the fact is that the 777 has surpassed it in almost every meaningful aspect. The newer, smaller widebody has enhanced nearly every tangible part of the travel experience for both operators and customers alike.
United’s Young Fleet
Some of the aircraft in the United Airlines 777 fleet are just over five years old, while the oldest are approaching nine years old now, according to ch-aviation. The airline did not order any of the successor aircraft, the 777X, nor did the other two carriers of the “big three” in the US: American Airlines and Delta Air Lines. The logic seems simple, UA already has an aircraft that performs its role perfectly and will endure for decades to come.
The triple seven is not only the largest aircraft by seat capacity and the longest-range plane in the fleet, but it is also the most well-equipped. That is thanks to its spacious cabin, which accommodates many premium seating classes. The triple seven is favored by many carriers famous for exceptionally high-quality products and services, like Emirates or Singapore Airlines, and United’s does not disappoint.
The configuration of the -300ER jets flown by United includes 60 United Polaris business class seats, 24 United Premium Plus seats, 62 United Economy Plus seats, and 204 United Economy seats for a total of 350 seats. That is about 10% less than the aircraft can actually fit, according to the maximum count that Boeing lists on the website for the 777 family.
Onboard United’s 777-300ER
The Polaris business class is the flagship product, with a suite-like pod that converts into a six-foot-six-inch, 180-degree flatbed. The cabin space is also arranged so that every seat has direct aisle access in a 1-2-1 configuration. The amenities provided come with a Saks Fifth Avenue bedding kit as well as a pillow duvet and Therabody hygiene goods.
In the Premium Plus section, the seats are wider at 18.5 inches and have more recline, up to 6 inches. The same Saks Fifth Avenue amenities are provided for passengers who book in this class as well.
In Economy Plus, seats have 34 inches of legroom, which is three inches more than the economy section. The seats are located at the front of the economy cabin, closer to access for boarding and deplaning. Power and USB ports are available in the seats, as in the standard economy section.
Economy class gets the same inflight service, such as dining menus and entertainment. However, the seats are a bit more cramped with 31 inches of pitch. In this section, which is the largest by total seat count, each row is 10 wide and arranged in a 3-4-3 layout.
Where The Triple Sevens Roam
The most popular routes for United’s fleet of -300ER widebodies are international flights, originating in the United States. The most popular destination is Manila International (MNL), in the Philippines, with service from San Francisco Airport (SFO). Also, connecting Stateside through San Francisco is the second most popular itinerary, which goes to Hong Kong Airport (HKG) in China.
The third most frequently flown transoceanic route by the UA triple sevens is from Washington, DC’s Dulles Airport (IAD) to Brussels Airport (BRU) in Belgium. Taking fourth place is a transatlantic flight from Newark Liberty Airport (EWR) to Dubai International (DXB) in the United Arab Emirates (UAE). Fifth place goes to Frankfurt Airport (FRA) in Germany, with service from Newark again.
Below is a breakdown of the data recorded by ch-aviation for the scheduled 777-300ER flights that will be operated by United Airlines in November 2025. This snapshot highlights the five most popular itineraries for the month that will ferry the most flyers.
|
Origin |
Destination |
Round Trips (November 2025) |
Seats |
Average Miles (One Way) |
|---|---|---|---|---|
|
SFO |
MNL |
61 |
42,700 |
6,987 |
|
SFO |
HKG |
60 |
42,000 |
6,927 |
|
IAD |
BRU |
30 |
21,000 |
3,892 |
|
EWR |
DXB |
30 |
21,000 |
6,861 |
|
EWR |
FRA |
30 |
21,000 |
3,870 |
In the month of November, the total number of flights that United’s -300ER jets will fly is 781 with 22 airplanes. The jetliners will have a total seat capacity of 273,350 between them. On average, the route length in the portfolio of this widebody fleet is over 5,000 miles. The total mileage by seat count adds up to nearly 1.5 million, also known as available seat miles (ASM).
By The Numbers: 777-300ER
The largest of the triple sevens, the – 300ER featured several innovative new technologies when it first debuted in the 2000s. From the very beginning, the aircraft is already groundbreaking as it would be the first commercial airplane engineered entirely using computer-aided design (CAD).
The big jet’s wing was made with a supercritical airfoil as well as raked wingtips, which not only made the plane more fuel efficient but also improved performance. The plane was fabricated with extensive use of composite and new alloy materials that made it lighter, stronger, and lower maintenance.
The General Electric GE90-115B engine is officially rated to produce 115,000 pounds-force (lbf) of thrust, which is equivalent to approximately 115,000 horsepower at typical cruise conditions. During certification testing in 2002, the engine set a world record of 127,900 lbf (568.9 kN) of thrust, a record only recently surpassed by the GE9X designed for the 777X.
|
Specification |
|
|---|---|
|
Seats (2-class) |
392 |
|
Range |
7,370 nautical miles (13649 kilometers) |
|
Length |
73.9 meters (242 feet 4 inches) |
|
Wingspan |
64.8 meters (212 feet 7 inches) |
|
Height |
18.5 meters (60 feet 8 inches) |
The 777 family was a pioneer in ETOPS (Extended-range Twin-engine Operational Performance Standards) certification. The series was the first to be certified for ETOPS-180, allowing flights up to 180 minutes from the nearest airport. This changed the way carriers plan their fleets for long-haul travel and set the stage for the demise of quadjets like the Boeing 747 and Airbus A340 or A380.
Sunset Of The -300ER
The -300er was introduced in the early 2000s by Boeing as an extra-long-haul variant of the 777 series with an extended fuselage, more seats as well as more powerful engines. The gargantuan twinjet can seat nearly 400 passengers, with its maker listing the maximum at 392.
The plane is powered by General Electric’s GE90-115BL, which remains the most powerful commercial turbofan jet engine in the world. At least it will be until the GE9X debuts with the upcoming 777X, which will succeed the -300ER as the largest twinjet in aviation history.
According to various sources online, the final 777-300ER has likely already been delivered, with no more of the type to be produced by Boeing. According to Airlineratings.com, no official announcement has been made by the manufacturer, but the last jet appeared to be turned over to its new owner in September 2025.
