(ABC 6 News) – The Pentagon now believes it knows the cause of a mechanical failure that caused a deadly osprey crash that killed eight service members in November.

Officials have declined to state what the exact failure was.

The military’s osprey fleet was grounded for two months following the crash.

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One of the service members killed in the crash was Andover airman Major Jeffrey Hoernemann.

The military is now weighing how it can safely begin using ospreys again.