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Marine Electronics


June 2011 Issue

ROV Recovers Black Boxes from Downed Air France Flight 447
An ROV designed and operated by Phoenix International Holdings Inc. (Largo, Maryland) successfully located and recovered both black boxes from Air France Flight 447 between April 27 and May 2. The downed Airbus had been the target of three extensive but unsuccessful searches since its loss in June 2009 on a flight from Rio de Janeiro to Paris. Its wreckage was located April 3 during a fourth search.

The recoveries were completed in a short period of time, Phoenix said, given the technical complexities of operating in water depths of 3,900 meters. Phoenix's Remora ROV located the flight data recorder (FDR) within 12 hours on its first dive on April 27, but the critical memory unit had separated from the chassis of the FDR. An intensive and methodical visual survey of the seafloor was then initiated.

With Remora operating around the clock, the unit was found on May 1 and brought to the surface. Remora returned to the debris field to commence the search for the cockpit voice recorder, which records supplemental data critical to the investigation into the cause of the crash.

On May 2, the intact voice recorder was located and brought to deck of Ile de Sein, the Alcatel–Lucent (Paris, France) cable ship supporting the recovery project. Both boxes will be returned to France for analysis. Phoenix said Remora will continue to survey the debris field and recover items of interest as directed by the French Bureau d'Enquetes et d'Analy?ses and the on–site investigative team. For more information, visit www.phnx-international.com.

US Coast Guard Helicopter Crew Helps Retrieve Acoustic Mooring
A U.S. Coast Guard MH–60 Jayhawk helicopter crew from Air Station Kodiak, Alaska, with an Alaska Depart?ment of Fish and Game (ADF&G) wildlife biologist aboard, recovered a wayward acoustic mooring from a northern beach on the Shelikof Strait in late April.

The mooring, one of 10 located throughout Cook Inlet used to monitor the presence of beluga whales year–round, was noticed by a Kodiak resident, who reported his finding to ADF&G. It was located several hundred feet up on a beach in the splash zone just beyond the intertidal zone among a lot of beached logs.

"Because of the location we couldn't have done this without the Coast Guard," said Larry Van Daele, a Kodiak–based biologist who accompanied the aircrew. "Due to the lumber and the steep angle of the beach we couldn't use a wheel plane to land on the beach, so ADF&G through our National Marine Fisheries Service counterparts requested Coast Guard assistance to retrieve the mooring."

It is unclear exactly why the mooring became free. It's possible the acoustic release was triggered accidentally, or it may have been released in a previous season and failed to come to the surface for retrieval, scientists said.

Each mooring has two acoustic instruments, an ecological acoustic recorder that records sounds at lower frequencies, including those of belugas, and a Chelonia Ltd. (Cornwall, England) C–POD that recognizes and tallies the belugas' higher frequency echolocation clicks in the vicinity.

The mooring, valued at $20,000, will be evaluated and any repairs needed will be made before it is returned to service, ADF&G scientists said. For more information, visit www.uscgalaska.com.

Barcodes, Falcon ROV Used To Prevent Fishery Equipment Loss
In order to reduce the risk of fish farmers' cages drifting away into the open sea, Dive Works (Tasmania, Australia) has developed a system that integrates three complimentary technologies: verification of anchorage, mapping to monitor a shift in location and checking on the integrity of links and shackles.

The Net Secure System uses a Saab Seaeye (Hampshire, England) Falcon ROV to observe the procedure and ensure the correct positioning and soundness of the anchorage. The Falcon checks the thickness of shackles using ultrasonic thickness technology so those at risk can be replaced before they break. The ultrasonic thickness probe fitted to the ROV does not need to touch the metal part to capture a reading and transfer the data topside, where time, date and thickness is displayed and logged.

Next, the latitude and longitude of each anchor point is recorded into a mapping system. A reflector with a barcode is located at each anchor point so the ROV can make routine checks and alert the operator to any shift in a location.

With fish farming growing as an industry worldwide and yielding 90 million tonnes a year, Dive Works' managing director Andrew Ford said he sees the system having global appeal. For more information, visit www.diveworks.com.au.

Hydroid AUV Aids in Discovery of Missing German WWI U–Boat
A REMUS 100 AUV from Hydroid Inc. (Pocasset, Massachu?setts) aided in the discovery of the World War I German submarine U–106, the company said in May. The Royal Netherlands Navy (RNLN) used the vehicle to locate the missing submarine, which had been missing since October 1917, off the coast of Terschelling in the Netherlands.

In October 2009, the RNLN hydrographic survey vessel HNLMS Snellius located an unidentified object while charting shipping lanes. This was followed two months later with an inspection by a mine countermeasures vessel, the HNLMS Maass?luis. A wire–guided ROV designed to locate mines detected the shape of the vessel.

The discovery prompted a series of research missions, which employed the REMUS 100 as well as divers from the RNLN's Diving and Explosive Ord?nance Disposal Group (EOD). The REMUS ROV and the EOD divers descended 40 meters to explore the area, where a brass plate bearing the serial number of the submarine was discovered. After further exploration, as well as confirmations from the German Ministry of Defence and the families of crew members, the submarine was positively identified as the German U–106, which sunk during the World War I.

"These findings always happen by chance," expedition leader Capt. Lt. Jouke Spoelstra said. "Twelve years ago, a hydrographic survey ship passed the same spot of our discovery, but the German vessel must have still been under a layer of sand. We were lucky to be at the right place at the right time."

For more information, visit www.km.kongsberg.com/hydroid.

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