A former U.S. Air Force intelligence officer said he believes he has found the wreckage of Amelia Earhart's plane, which disappeared nine decades ago, on the bottom of the Pacific Ocean using sonar data from a deep-sea drone.

Hoping to solve an 87-year-old mystery, explorer Tony Romeo plans to launch a mission later this year or next year to find the long-lost plane, which a large-scale American search in 1937 failed to locate.

Earhart is America's most famous missing person, and Romeo said: "As long as she is missing, there will always be someone looking for her. If we can help end this story and bring Amelia home, we will be very excited."

Earhart, an American aviator, became the first woman and the second person ever to fly solo nonstop across the Atlantic in 1932, five years after Charles Lindbergh achieved this feat. She was attempting to fly around the world with navigator Fred Noonan when their plane was lost over the Pacific Ocean. Had she succeeded, she would have been the first female aviator to do so.

Romeo, CEO of private exploration company Deep Sea Vision, believes Earhart's plane wreckage lies on the ocean floor more than 5,000 meters (16,400 feet) below the surface, about 160 kilometers (100 miles) from Howland Island, roughly halfway between Hawaii and Australia.

He said that unclear sonar images taken by the deep-sea drone show a plane-like shape on the flat sandy ocean floor.

The 16-person Deep Sea Vision crew searched over 13,400 square kilometers (5,200 square miles) over 100 days at the end of last year.

Romeo said the images showed what appears to be a plane matching the size of Earhart's Lockheed Model 10-E Electra, and the image apparently shows a distinctive feature of the plane: the twin vertical stabilizers on the tail.

Romeo assumed that Earhart's fuel ran out and the plane landed on the ocean surface, then later sank to the bottom, where it would have rested since, undisturbed by currents.

He said, "The first step is to confirm that," and "the next step would be, if possible, to raise it to the surface and recover it," adding that the process could take years."