Rolls-Royce will spend hundreds of millions of dollars in the coming years to fix corrosion-prone Trent 1000 engine turbines on more than 200 of Boeing’s 787 Dreamliner models, according to reports.

Mark Harkin, CC BY-SA 2.0, via Wikimedia Commons

Rolls-Royce will spend hundreds of millions of dollars in the coming years to fix corrosion-prone Trent 1000 engine turbines on more than 200 of Boeing’s 787 Dreamliner models, according to reports.

Problems began to surface with the Trent 1000 in early 2016, when issues were reported with cracking on engine turbines on Dreamliners operated by Japanese carrier ANA. In August of that year, Rolls-Royce announced it would be replacing turbine blades on all Trent 1000-powered 787s after it uncovered problems with the coating on blades in the intermediate pressure area. ANA was forced to cancel flights while some of its 787s were grounded.

EASA Blames Sulfidation

Last December, the European Aviation Safety Agency issued an Emergency Airworthiness Directive concerning the Trent 1000 engines, placing a cyclical life limit on the engines with their original intermediate pressure turbine blades. When an engine reaches its limit, it must be removed so that the blades can be replaced.

The EASA specifically blames sulfidation corrosion for the cracking that has led to the blades breaking.

Sulfidation corrosion was also blamed recently for a 2016 incident in which a passenger jet in India had to return to the airport shortly after departure when smoke filled the cabin. That plane, an ATR 72-500, much smaller than the Dreamliner, experienced the failure of a turbine blade in its Pratt & Whitney PW127M engine.

Chihaya Sta, public doman, via Wikimedia Commons

Rolls-Royce's Trent 1000 engine, on upwards of 200 787s, has been prone to sulfidation corrosion, causing turbine blades to crack.

Sulfidation occurs at high temperatures and in airplanes can be brought on by the sulfur in jet fuel as well as environmental exposure. The corrosion process can be exacerbated in materials that contain niobium, which the blades in the affected Pratt & Whitney engines contained. A chromium coating can reportedly slow the corrosion.

Sulfidation corrosion also occurs in oil and gas applications; it was blamed for a 2012 blast at a California Chevron refinery, as well as a massive explosion at a refinery in Utah in 2009.

Replacement Costs Rise

According to the Seattle Times, Rolls-Royce has spent $315 million so far replacing turbine blades in the affected Trent 1000 engines. Some Trent 900 engines, powering the Airbus A380, are also affected by the issue.

The urgent fixes have caused issues for major airlines that rely on the Dreamliner; Virgin Atlantic recently characterized the Trent 1000 situation as "seriously disruptive," according to Bloomberg. The airline reportedly has borrowed planes from sister company Delta, and is leasing two Airbus A330s formerly operated by a now-defunct airline to make up capacity with as many as three 787s down at a time.

All 787 Dreamliners use either Rolls-Royce’s Trent 1000 or General Electric’s GEnx.