Why Boeing didn’t stick with one engine option for the 787 – Jalopnik

Despite some significant safety issues – including those resulting from the fatal Air India Boeing 787 crash in June 2025 – the so-called Dreamliner remains a popular choice for airlines today. Boeing has delivered more than 1,175 Dreamliners through April of this year, and these planes have carried more than a billion passengers.

There are two engines available for the 787 family: General Electric’s GEnx-1B and Rolls-Royce’s Trent 1000. Each engine has its own unique strengths. By giving customers a choice, they can choose the power plant most suitable for specific routes. Airlines may also already have experience repairing or maintaining a particular engine, and the choice allows them to keep their operations consistent.

Another advantage of Boeing’s strategy is that it increases availability; If one engine manufacturer has supply chain problems, another may be able to take its place. That way, Boeing won’t have all its jet-powered eggs in one basket. But beyond customer appeal and risk management, is there a real difference between the GEnx-1B and the Trent 1000? Let’s find out!

First, let’s look at some similarities. One of the most important of these is that the motors are easily interchangeable. The 787 was the first commercial aircraft to use the same interface with two different engines. Boeing believed this would be attractive not only to airlines, but also to financiers and leasing companies. In some cases, those trying to purchase an aircraft with a particular engine may not find their preference available. However, their agreements would make it easier for buyers to purchase the plane anyway so they could get the “right” engine later.

As for the engines themselves, both are turbofan jets that deliver thrust in two ways. The core is a standard jet engine that burns a mixture of fuel and air. There’s also a bypass system that allows some of the intake air to bypass combustion, with a fan channeling it around the core before expelling it out the back. The result is an engine that produces more thrust than the jet aircraft alone, while using less fuel than a larger power plant producing the same power. It is that combination of advantages that has allowed the aviation industry to move away from tri-jet commercial aircraft.

Rolls-Royce’s engine has a particularly high bypass ratio of 10:1, compared to the 8.8 to 9:1 ratio on the GEnx-1B. Bypass ratios look at the amount of air that avoids combustion and shoots straight to the rear, compared to the air that actually enters the engine. Specific to the Trent 1000, this means that the fan – and not the more fuel-hungry aircraft – produces approximately 85% of the engine’s thrust.

General Electric also takes an innovative approach to engine design by using lightweight carbon fiber composites for components such as the turbofan blades and housing. Speaking of fan blades, the GEnx-1B managed to reduce its number to 18 – down from 22 in the previous version – to save even more weight. The Trent 1000 features 20 turbofan blades and three compressor shafts compared to the pair used by GEnx-1B. This was done to increase efficiency, extend engine life and improve the aerodynamics of the Rolls-Royce engine.

But what may be the biggest difference in the actual capabilities of the engines has to do with their initial reliability. The Trent 1000 was launched with a host of issues that led to expensive repairs for customers, forcing them to deal with the costs and downtime required to make these repairs. Rolls-Royce responded with design improvements from other power plants, but even British Airways decided to drop the London-headquartered Rolls-Royce engines for the GEnx-1B. It’s also worth pointing out that these aren’t the only companies building Boeing’s jet engines.