The low pressure turbine failed in the Pratt & Whitney Geared Turbo Fan engine on Bombardier’s CSeries, reports investment bank UBS, citing Bombardier.
BBD confirmed that recent GTF engine failure was in the low-pressure turbine and that the airframe (FTV1) was damaged in the incident, but downplayed the impact to the program schedule. While root cause analysis is ongoing, BBD emphasized that the failure was unrelated to the gearbox, and also suggested that a manufacturing defect (rather than a design flaw) may have been the cause. The subject engine was known to have problems, and BBD had considered sending it back to Pratt prior to incident on 5/29. Engine was instead repaired at BBD and the failure occurred during subsequent ground-testing. Root cause expected by end of week, corroborating message from our meetings with UTX on Monday.
The LPT is at the rear of the engine. A BBD official told us previously that FTV 1 was equipped with prototype engines, and that the production engines are first installed on FTV 4, the airplane that is designated to validate engine performance.
Engine failures during test programs are rare but not unknown. Rolls-Royce experienced a test-stand engine failure of the Trent 1000 for the Boeing 787 in which components blew apart.
Separately, a GEnx engine spit parts out of the back of the engine while a 787 was taxiing at Boeing’s Charleston 787 plant. Neither incident has serious impact on the program.