GE Aerospace Pays $11.75 Billion to Own Its Jet Turbine Blades

GE Aerospace agreed in September to buy its turbine blade supplier for $11.75 billion (£8.78 billion) — the clearest price tag yet on one of aviation's most guarded manufacturing secrets. Neither company commented on the deal, but industry observers read it as a move to lock down supply of components that only a handful of firms can produce.

The components in question are single-crystal turbine blades: hundreds of small blades inside every jet engine that withstand temperatures above 1,500C and enormous mechanical stress. Rolls-Royce, GE and France's Safran are among the few companies that have perfected the casting process end-to-end, and only five countries — including the US and UK — host the full capability. Engine-makers continually compete for access to the technology.

What makes these blades so hard to build?

The blades are not machined or cut. They are grown. Engineers in the 1960s worked out how to cast a molten metal alloy into a blade shape and cool it slowly, over hours, from one end to the other, so that a single crystal of alloy forms. Ben Fifoot, a manufacturing engineer at Rolls-Royce, which makes blades in the UK, calls it "about as complicated as manufacturing gets" and "a real motivator to get out of bed in the morning."

To grow one, he says, is to "fight the laws of the universe." Left alone, molten alloy would solidify into many small jumbled grains — a crumbly sugar cube rather than a perfect diamond. The fix is a "pigtail": a small spiral at one end of the casting that "chokes" the flow of solidifying crystals so that just one takes over, Fifoot explains. Engineers tune the spiral's turns and angles to get a favorable grain, then cut the sacrificial spiral off once the blade forms. When a blade cools wrong — say, two crystals form — the alloy must be reprocessed for reuse.

Rolls-Royce's blades fly in the Trent XWB-84, which powers the Airbus A350-900, and the Trent 1000 XE for the Boeing 787. In March, Rolls-Royce committed more than £19 million to its blade casting facility in Rotherham.

How do the blades survive 1,500C?

Ceramic coatings protect them, and cast-in channels feed cooler air across the blade surface as a film. Paul Withey of the University of Birmingham, a former Rolls-Royce engineer, says the industry's current drive is "to make those cooling passages really intricate" — the more turbulent the cool air, the more heat it strips from the surrounding hot gas. Weight matters too: "If we can take any weight out of it, you can run that engine more efficiently using less fuel — you can spin it faster and hotter," Fifoot says.

"Demand for [turbine blades] is huge. So few companies have managed to do it, which does give it this kind of magical aura," says Bill Sweetman, an aviation industry writer and consultant. He suspects GE's acquisition is about securing reliability in a notoriously volatile supply chain.

Can China catch up?

China wants to become only the sixth country to master the full single-crystal casting chain. A May report quoted an engineer at the AECC Beijing Institute of Aeronautical Materials claiming China now has an alloy "superior to or equivalent to the second-generation single-crystal superalloys widely used in Europe and the US" — and cheaper to make. The claim is unverified, and the gap is measured in more than metallurgy.

Sweetman says the West holds a "huge advantage" because most commercial airliner production sits there, along with the clustered supply chains, the latest innovations, and long safety records. China must compete across essentially every aspect of aircraft manufacturing, not just blades: "You can definitely see that happening but it's a long, uphill struggle," he adds.

Demand could rise further. Withey suggests Airbus or Boeing may launch a new short-haul plane in the next few years, forcing the other to follow. "There'll be a bun fight," he says, over who supplies the engines — and, by extension, the blades. Whoever wins that fight will need foundries already running at capacity in five countries.