Small plane that crashed off California coast was among a growing number of home-built aircraft
LOS ANGELES — A small plane that crashed into the ocean off the coast of California on Sunday was built piecemeal over nearly a decade, one of tens of thousands of homebuilt planes that are part of a high-flying hobby taking off across the country.
Federal investigators said they believe four people were aboard the single-engine Cozy Mark IV when it went down just south of San Francisco that evening. No survivors were found and only one body had been recovered and identified from the waters off Half Moon Bay on Thursday.
The names of the pilot and two other passengers have not been released. According to Federal Aviation Administration records, the plane was registered to an Oakland-based company called Winged Wallabies, Inc.
There are no official clues as to what went wrong, but a witness reported hearing an engine losing power and cutting out.
Thane Ostroth, a retired dentist who started building the plane in 1999 and flew it in 2008, said he sold the plane last year to a young, experienced and enthusiastic pilot from Australia for about $100,000, which is about what he estimates that a lot of effort went into the project. through the decades.
Ostroth said the buyer, in his late 20s, knew a lot about airplanes. He landed the plane perfectly on his first test flight, which is not easy.
“I told him, ‘That was well done,’” Ostroth recalled. “He said, ‘Thank you. I’ll buy the plane.’”
Authorities have not said whether the plane’s owner was among the occupants.
Ostroth said he heard about the crash in an online chat group for pilots and builders of Cozy planes, a class of aircraft built by individuals rather than mass-produced by companies.
He said it was “traumatic” to know that the plane he had spent so much time in had crashed with people on board.
“It’s just a terrible feeling,” Ostroth said.
Like commercial aircraft, all home-built aircraft must be inspected annually by the FAA for airworthiness. Cozy planes have the same safety record as similarly sized commercially built planes, said aeronautical engineer Marc Zeitlin, who consults with the National Transportation Safety Board on crash investigations involving Cozy planes, including this one.
More than 33,000 amateur-built aircraft are licensed by the FAA, a number that has tripled since the 1980s.
The government labels any non-commercial recreational aircraft as “experimental.” This may involve aircraft that are constructed from kits with a number of prefabricated parts, or from plans in which the builder purchases or manufactures and assembles all parts.
The four-seat Mark IV, just over 5.1 meters long with a wingspan of 8.5 meters, is a popular aircraft among the growing number of aviation hobbyists who are building their own aircraft. Zeitlin has one himself that he uses for day trips and cross-country ski trips.
“The misconception is that these are put together by baling wire and glue,” said Zeitlin, CEO of California-based Burnside Aerospace. “But they are built using aircraft methodology.”
The Mark IV has a ‘canard’ design, with a small forewing at the leading edge of the main wing, making it reminiscent of an outstretched duck in flight. It is lightweight, only about 475 kilograms empty, with the parts assembled together with epoxy.
With a top speed of almost 200 mph (322 km/h), it is fast, stable and economical, Zeitlen said.
“Like a sports car in the sky,” he said. “Very fun to fly.”
Ostroth said he bought the plans for his Cozy for about $500 and started putting them together in a friend’s basement in Michigan. Ultimately, they moved the structure into the home’s garage and then built a shed in the backyard for the final steps.
“The plans include a list of authorized parts suppliers,” said Ostroth, who now lives in Florida. “You buy foam, you buy fiberglass, you buy metal parts from all manufacturers. And you slowly piece it together.”
Help can be found from other enthusiasts who post tips and advice on online forums.
Ostroth flew the plane regularly for 15 years. He called it “a beautiful little airplane.”
Sunday’s crash was reported around 7 p.m. by a 911 caller who said the plane was in apparent distress and appeared to be descending toward the water near Ross’ Cove, according to the San Mateo County Sheriff’s Office.
The U.S. Coast Guard said a helicopter and boat crew searched a 73-square-mile area for nearly six hours before calling off the search mid-morning Monday. A few hours later, a woman’s body was found by the crew of a commercial fishing boat. The San Mateo County Coroner’s Office identified her as Emma Willmer-Shiles, 27, of San Francisco.
The National Transportation Safety Board said its investigators were at the scene Tuesday to document the wreck and interview witnesses. A preliminary report is expected within 30 days.
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Associated Press writer John Antczak in Los Angeles contributed to this report.