The Navy says it has been confirmed that it is impossible to repair the cockpit voice recorder(CVR) of the maritime patrol aircraft that crashed in the southeastern city of Pohang last month, killing all four Navy officers on board.

The Navy announced on Friday that a joint civilian, public and military team tasked with probing the accident was notified by the National Forensic Service and a private firm that repairing the CRV is not possible. 

The joint probe team had requested the forensic agency and the private company to analyze the CVR which was retrieved from the aircraft. 

The CVR was regarded to be one of the key equipment that could shed light on what happened on May 29 as it is used to record the audio environment in the flight deck. 

The P-3C maritime patrol plane crashed on a mountain in Pohang around 1:50 p.m. on May 29, six minutes after lifting off from the Pohang naval base for a training mission.