New search opens for plane carrying 3 that crashed in Michigan's Lake Superior in 1968

A high-tech unmanned boat outfitted with sonar and cameras is trying to solve the mystery of a 1968 plane crash that killed three people who were on a scientific assignment at Michigan's Lake Superior.

Seat cushions and pieces of stray metal have washed ashore over decades. But the wreckage of the Beechcraft Queen Air, and the remains of the three men, have never been found in water as deep as 400 feet (122 meters).

An autonomous vessel known as the Armada 8 was in Lake Superior on Monday, joined by boats and crew from Michigan Tech University's Great Lakes Research Center in Houghton in the state's Upper Peninsula.

''We know it's in this general vicinity,'' Wayne Lusardi, the state's maritime archaeologist, told reporters. "It will be a difficult search. But we have the technology amassed right here and the experts to utilize that technology.''

The plane carrying pilot Robert Carew, co-pilot Gordon Jones and graduate student Velayudh Krishna was traveling to Lake Superior from Madison, Wisconsin, on Oct. 23, 1968. They were collecting data on temperature and water radiation for the National Center for Atmospheric Research.

Searches of the lake that fall and in 1969 did not reveal the wreckage.

''It was just a mystery,'' Lusardi said.

''Any wrecked aircraft is treated very much similar to a wrecked (ship) in the Great Lakes. It won't be disturbed," White said on an afternoon livestream from Lake Superior. ''What we're trying to do is document its location and condition and try to provide as much of an answer as we can to the question of what happened.''

Family members of the three men who died are aware of the new search.

This isn't a solo mission. The autonomous vessel will also be mapping a section of the bottom of Lake Superior, a vast body of water with a surface area of 31,700 square miles (82,100 square kilometers).

The search is being organized by the Smart Ships Coalition, a grouping of more than 60 universities, government agencies, companies and international organizations interested in maritime autonomous technologies.

"We will have a successful mission at the end of this week showing a new application for technology, new things found on the lakebed in an area that's not been previously surveyed in this way,'' said David Naftzger, executive director of the Great Lakes St. Lawrence Governors & Premiers, a group of U.S. states and Canadian provinces.