Thursday, March 20, 2014

How Naval Drones Could Help Solve the Mystery of Malaysian Airlines Flight #370

If airborne search assets succeed in finding the wreckage of Malaysian Airlines Flight #370, what happens
US Navy Towed Pinger Locator.
next?  Generally, the key to determining the cause of air plane crashes at sea is dependent upon the recovery of the data recorder, or "black box" as it is generally known.  A black box has an acoustic "pinger" which is activated upon hitting the water and transmits a signal, sometimes for up to 30 days.  Once crash debris is spotted on the ocean, salvage experts will use predictive modeling software to determine an approximate location of where the aircraft actually went down.  Even small ocean currents of a knot or two can push floating debris hundreds of miles away from the original crash site over a two week period.

At that point, if it is determined that one or more of the regional navies involved will search for the black box, a towed pinger locator will be deployed from a ship, along with a towed side scan sonar or deep-water capable unmanned underwater vehicle (UUV).  This equipment can be flown in rapidly and deployed from a Navy salvage ship or other appropriate vessel - like Australia's hydrographic survey ships - in the area.  In the case of the U.S. Navy, the Supervisor of Salvage is responsible for these operations.  According to SUPSALV, "The Pinger Locator is towed behind a vessel at slow speeds, generally from 1 - 5 knots depending on the depth. The received acoustic signal of the pinger is transmitted up the cable and is presented audibly, and can be output to either a Oscilloscope, or Signal Processing Computer. The operator monitors the greatest signal strength and records the navigation coordinates. This procedure is repeated on multiple track lines until the final position is triangulated."      

Assuming the black box can be found with those assets (keep in mind, finding it will be as difficult and time consuming, if not more, than finding the surface debris), then a decision will be made on how to recover the black box and any critical pieces of the wreckage found that might help the forensic investigators determine what caused the plane to go down.  Only in cases of shallow water (generally under a 100 meters or so) will Navy divers be used.  The Indian Ocean averages about 4,000 meters.  For those depths, a Remotely Operated Vehicle (ROV), such as the U.S. Navy's CURV will be deployed to pick up the black box and any small pieces of the aircraft wreckage. ROVs have also be used in some cases to recover any human remains from deep water.

Even with the best technology, underwater, salvage, like mine hunting, is a very painstaking operation, and results don't happen quickly.  Similar aircraft recovery operations, have taken weeks, or even months.