CNN is reporting that the unmanned underwater vehicle Bluefin 21 has already aborted its first day of attempting to search for missing Malaysian Airlines Flight 370 in the Indian Ocean of Australia’s west coast, and come back to the surface.  The reason was that the ocean was apparently much deeper in the search area than originally believed.

Meanwhile, investigators now believe that the mobile phone belonging to co-pilot Fariq Abdul Hamid was turned on and made contact with a cell tower in Malaysia about the time the plane disappeared from radar.  But there’s no evidence that Hamid tried to make a call – it might just have been left on in his pocket.

A cell-phone tower in Penang, Malaysia, which is about 400 kilometers from the position where the missing Boeing 777-200ER’s transponder last sent a signal, detected the co-pilot's phone searching for service.  This would be roughly 30 minutes after authorities believe the plane made a sharp turn westward.

Generally, a cell phone tower can pick up one of these electronic handshakes from 1.5 to 1.8 kilometers, which backs up earlier theories that the plane’s altitude dipped way down into that range.  Some speculated that the plane did this to avoid being detected by radar, but the fact remains that not much will be known for certain until the black box flight data and voice recorders are recovered – And there’s been no electronic signal from them in about a week.