May 22—Federal authorities are looking into whether fuel-system problems caused a crash Saturday that killed the pilot and co-pilot of a twin-engine plane that plunged into the Pacific Ocean off the San Mateo County coast.
The two people, who had not been identified as of Monday afternoon, were the only passengers aboard the twin-turboprop deHavilland, a plane known as a Twin Otter, which took off from Santa Rosa and was bound for Honolulu, the Federal Aviation Administration said.
Shortly into the flight, with the plane about 70 miles off the coast, the pilots radioed air traffic controllers in Oakland to report that they were having mechanical problems and were headed to Half Moon Bay but didn't expect to make it, according to U.S. Coast Guard spokesperson Petty Officer 2nd Class Matthew West.
The Coast Guard was alerted to the emergency and sent out a helicopter, which spotted the plane, upside down and partially submerged about 40 miles west of Half Moon Bay, where the plane had apparently been headed after it developed fuel problems, Coast Guard officials said.
A rescue swimmer found both of the plane's occupants in the cockpit, unresponsive, Coast Guard officials said. Their bodies were not immediately removed from the plane, West said.
The San Mateo County Coroner's Office said Monday afternoon that it had not received the bodies for identification, and that officials at the office were not sure whether they would.
The National Transportation Safety Board, which is investigating the incident, said Monday that it is looking at fuel starvation — when insufficient fuel is delivered to the engine — as a potential cause of the crash.
Fuel starvation is not the same as fuel exhaustion or running out of fuel, said spokesperson Sarah Taylor Sulick.
The aircraft, which normally would not be able to hold enough fuel to make it to Hawaii, was outfitted with a supplemental fuel system, known as a ferry tank, which would allow it to make it that far, Sulick said, describing it as a fairly normal practice.
"At this time, investigators believe there was enough fuel, but the system wasn't properly transferring the fuel from the added ferry tanks to the main tanks," she said.
The NTSB is working with a salvage company to retrieve the plane.
Crash investigators are collecting information about the plane's maintenance history, the pilots' background and training, and satellite communication data on the plane's flight, Sulick said. A preliminary report is expected to be published 15 days after the accident, but a complete investigation will take 12 to 24 months to complete, she said.
Reach Michael Cabanatuan: firstname.lastname@example.org; Twitter: @ctuan
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