The US FAA has confirmed the 2 August engine failure of the 'Package A' Rolls-Royce Trent 1000 was uncontained.
The incident, which occurred during a ground test at the engine-maker's Derby, UK test facility, has been initially linked to the failure of the engine's intermediate pressure (IP) turbine.
Following the initial incident, neither Rolls-Royce nor Boeing would confirm the failure had not been contained within the engine.
A report from Bloomberg quoted Rolls-Royce as saying debris from the failure had damaged the test facility - designated 'Bed 58' - and repairs were expected to be completed shortly. The report also added that EASA has dispatched a representative to the UK to work with Rolls-Royce during the investigation.
The FAA says that no one from its office was sent to the UK, as EASA is the certifying authority.
The Trent 1000 engine involved in the failure was destined for an early All Nippon Airways Boeing 787. Rolls-Royce will initially deliver 'Package A' engines for the first ANA 787s before transitioning to the 'Package B' standard, which will bring specific fuel consumption within one percent of the original specification.
An investigation into the failure is currently ongoing and Boeing is working closely with Rolls-Royce to evaluate if it can proceed with early 787 production flights with the 'Package A' engine, though the airframer says the incident has not impacted flight testing "to date".
Four of the six 787 flight test aircraft are powered by the Trent 1000.
While not specifically addressing what it believes led to the failure, Rolls-Royce has said "a modification is already in place for later engines".
The engine manufacturer has not indicated if modification would be fed back into the 'Package A' engine build.
Boeing offers a choice of Rolls-Royce Trent 1000 or General Electric GEnx-1B engines on the 787.
First delivery to ANA is expected by year-end; however, Boeing has indicated this target could slip to early 2011.