The operational fleet counts just nine aircraft right now, but Singapore Airlines’ announcement on April 2 that it has grounded two Boeing 787-10s due to Rolls-Royce Trent 1000 TEN issues does ring an alarm bell.
Reported by Channel News Asia (CNA), Singapore Airlines said it has removed two 787-10s from service after finding “premature blade deterioration” on some engines. As a precautionary and safety measure the airline wants to replace to affected engines before the aircraft re-enter service.
Although the news report mentions two Dreamliners, checking SIA’s active 787-10 fleet learns that only two were in service on April 2 (9V-SCG and SCH), while the other seven aircraft have not been operational since March 31 or even March 28. Also investigated are TENs on a Scoot 787-9.
In response to the news reports, Rolls-Royce has confirmed that “a small population of the Trent 1000 TEN fleet has flown in more arduous conditions”, without specifying what this means. The result is that High-Pressure Turbine (HPT) blades have shown signs of early deterioration and reduced life time, requesting early replacement of the affected blades. Rolls says that “our engineers have already developed and are testing an enhanced version of this blade”. “We will now work closely with any impacted customers to deliver an accelerated programme to implement the enhanced blade and to ensure that we can deliver on our Trent 1000 TEN future commitments. We regret any disruption this causes to airline operations.”
Starboard Rolls-Royce Trent 1000 TEN on the first Boeing 787-10 at the 2017 Paris Air Show. (Richard Schuurman)
The statement identifies that Rolls-Royce has been aware of HPT blade issues on the TEN for some time, as it says it has been responding by designing and testing and enhanced blade version. The latest issue is not related to previous problems with Pacakage B and C engines, Rolls-Royce says on its website: “The Trent 1000 TEN has high-pressure turbine blades with a known life cycle limit. This is seperatre to the Trent 1000 Package B and Package C durability improvements we’re already working on”.
Rolls-Royce completed a revised HPT blade as part of Package C last October that should solve higher than expected wear that was first seen late 2015. There was also seen sulphidation on IPT blades, corrected by introducing a new blade design with a different protective coating. Rolls also had to do a compressor rotor blade re-design, as vibrations were found that could cause them to crack. Only a small number of engines had a fourth issue with cracks in the IPC rotor seal.
The Derby-based company is in the midst of retrofitting these updates to in-service Trent 1000s while introducing them as standard on new engines.
Until now, Rolls-Royce was positive the corrosion issue was restricted to the Package C and B engines, while the improved Trent 1000 TEN had none of them. That’s why this latest issue could be more serious than Rolls-Royce want us to believe, although the restricted number of affected aircraft should allow the OEM to act swiftly.
Currently, there are 21 Boeing 787-10 is airline service: nine with Trent 1000 TENs with Singapore Airlines, eight with United Airlines with General Electric GEnx’, four with Etihad (also with GEnx). All Nippon Airways took delivery of its first Trent-powered -10 on March 31, but the aircraft still needs to enter service. A 22nd 2nd -10 is used by Boeing as a GEnx testbed. KLM is expected to take delivery of its first -10 in June.
Rectifying Trent 1000 issues and compensating airlines for grounding their Boeing 787s has been very costly to Rolls-Royce. The company took another £236mln exceptional charge in 2018 to a total of £790mln.
Active as a journalist since 1987, with a background in newspapers, magazines, and a regional news station, Richard has been covering commercial aviation on a freelance basis since late 2016.
Richard is contributing to AirInsight since December 2018. He also writes for Airliner World, Aviation News, Piloot & Vliegtuig, and Luchtvaartnieuws Magazine. Twitter: @rschuur_aero.
