Crews with the Contra Costa County Sheriff's Office looked for additional pieces of the Cessna 210 that went into the water on Sunday, lead National Transportation Safety Board investigator Howard Plagens said. Boats from the neighboring Richmond Fire and San Francisco Police departments were also helping the search.
The midair collision occurred when one pilot attempted a passing maneuver, he said. The pilot of a vintage Hawker Sea Fury TMK 20 pulled up to the left side of a travelling companion flying a Cessna 210 when the Sea Fury's pilot heard a "thump" and immediately focused on trying to fly his own plane to land safely, Plagens said.
Plagens said the pilot saw the Cessna going down but did not see it crash.
"Obviously, he's still shaken up," said Plagens, who interviewed the surviving pilot twice. Plagens added that he hopes to have a preliminary report about the crash by Friday.
Searchers on Monday located the Cessna under 13 feet of water about 1 1/2 miles off the Richmond shoreline east of San Francisco. The crashed plane and its pilot, the lone person onboard, haven't been recovered as officials haven't identified the two pilots involved.
Plagens inspected the Hawker, which suffered tail damage, and said he's awaiting the recovery of the Cessna to continue his investigation.
It was not immediately clear why the planes were flying so close together during the passing maneuver.
John Cox, CEO of the consulting firm Safety Operating Systems and a pilot with 44 years of experience, said the distance that pilots should maintain from nearby planes depends on whether the planes are flying together in formation.
"If they are not flying in formation, basically several hundred feet," Cox told The Associated Press. If they are flying in formation, that distance may shrink to as little as 30 or 40 feet, he said.
The overtaking plane — in this case, the Sea Fury — is responsible for maintaining separation, but it's possible that the surviving pilot didn't see how close he was to the Cessna, Cox said.
The collision occurred late Sunday afternoon near the Richmond-San Rafael Bridge. Witnesses at Point San Pablo Yacht Harbor said the Cessna spiraled out of control and crashed into the choppy water. Debris was found in the bay after the collision.
The Sea Fury's pilot landed at Eagle's Nest Airport in the small city of Ione in Amador County, said Federal Aviation Administration spokesman Ian Gregor. The Sea Fury's occupants — a husband and wife — weren't hurt.
Both planes had departed from Eagle's Nest Airport to participate in the Pacific Coast Dream Machines, an annual festival at Half Moon Bay Airport that features a variety of planes, motorcycles and cars. Both planes left Half Moon Bay, about 20 miles south of San Francisco, and were on their return flight.
FAA records indicate the Sea Fury, a vintage British fighter plane, is registered to Sanders Aeronautics Inc. in Ione. A man who answered the phone at the company's listed number declined to comment.
Sanders Aeronautics' website said the family-run company specializes in aircraft restoration, and brothers Dennis and Brian Sanders are avid air racers.