What happened
On June 20, 2017, a Boeing 787-9, registration CC-BGG, operated by LATAM Airlines Chile, was climbing through 36,000 feet en route from Lima, Peru, to New York, USA. The crew reported a loud noise originating from the number 2 engine, immediately followed by a total loss of power in that engine.
The rapid deceleration of the intermediate pressure (IP) shaft triggered the Intermediate Pressure Turbine Overspeed (IPTOS) system, which automatically performed an In-Flight Shut Down (IFSD) of the engine to prevent a potential uncontained engine failure. The crew declared an emergency, followed non-normal checklists, and successfully returned to Lima for a safe landing.
The investigation
An investigation by the CIAA, involving technical advisors from the UK's AAIB and Rolls-Royce, examined the engine (serial number 10371) during a teardown in the United Kingdom. The inspection revealed that a specific compressor blade (Blade2 #49) had been released from its slot. This release caused significant impact damage to the downstream vanes and blades within the intermediate pressure compressor (IPC) and high pressure compressor (HPC) sections.
Laboratory analysis of the fractured surfaces showed that the failure originated from cracks in the dovetail root of the blade. These cracks were found to have propagated via high cycle fatigue (HCF). The investigation confirmed that the damage was contained within the engine nacelle, with no damage to the aircraft structure.