A team on the San Diego-based USS Fort Worth is searching for the wreckage of AirAsia flight QZ8501 with advanced “Tow Fish” side scan sonar systems capable of spotting a “golf ball” on the ocean floor.
The Tow Fish side system is used to identify objects on the seafloor and provide accurate imagery for analysis. The sonar carries a passive listening device for detecting an acoustic pulse and is towed behind a vessel at slow speed. The acoustic signal is then transmitted to a computer where the trained operators are able to analyze the feedback.
“We can find things as small as a golf ball and something as big as an airplane using different kilohertz spans,” said Navy Diver 2nd Class Daniel Clarke. “Should we find targets out there, we will switch over to a very high resolution; we’ll go [over the area] very slowly and get very clear images. We can see everything on the sea floor using our computer”
Similar sonar systems have been crucial in past operations in 7th Fleet. In early 2014, U.S. 7th Fleet dedicated assets, including Bluefin-21 Sidescan Sonar systems, to assist in the search for MH370 and the Korean ferry Sewol search and rescue operations.
“We use this equipment quite often,” Said Clarke. “This type of equipment was used in stuff like finding MH370, or in the Sewol [South Korean ferry capsize tragedy], also with finding any type of other aircraft that might have gone down in the past.”
A second San Diego ship, the guided-missile destroyer USS Sampson, is also assisting with the search.