ΜΗ370: Fears that the singal of black boxes shut down

The investigations for the missing Boeing are continuing for fourth week, the Authorities are focusing in the discovery of the Black boxes.
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However, there are serious concerns that the batteries of black boxes may have expired, as the authorities have failed to identify the signal that ship Ocean Shield heard.

According to the head of the investigation Mr. Angus Houston, they are in a crucial point because the batteries of the black boxes may have expired, as the lifetime of that black box is nearly 30 days.

"There has been no further contact but we will continueour research for several days until the time that there will be absolutely no doubt that the batteries are discharged", said Houston.