The small plane that crashed this week off the coast of Half Moon Bay, California, was an “amateur-built” experimental craft, according to its federal classification.
But experts say that designation, which would normally limit where and when the craft could fly, is not necessarily the reason for its fatal crash.
The Cozy Mark IV, a single-engine, four-seat plane, crashed shortly after takeoff from Half Moon Bay Airport Sunday night, according to the National Transportation Safety Board. All four people on board, including the pilot, are now presumed dead, although only one person's body has been recovered and identified: Emma Willmer-Shiles, 27, of San Francisco.
The NTSB is still investigating the crash and it is unclear if the construction of the plane will be part of the investigation. Agency spokeswoman Sarah Taylor Sulick said aircraft maintenance will be a part of the investigation, as will other potential factors such as weather and the pilot's background.
Investigators will also review air traffic control communications and available surveillance footage or witness statements.
The small plane was considered a “homemade aircraft,” available for home construction from raw materials and prefabricated parts, making it part of a small subset of American aircraft, according to Robert Ditchey, an aircraft and litigation expert at aviation. in Marina del Rey.
“This particular type of airplane and the market for this type of airplane is minuscule,” Ditchey said. “Not many people want to build an airplane or have the time and money to do so.”
Because these planes are built by different people, often their owners, the process is less regulated and the plane “can be a danger to the public,” he said.
These aircraft are classified by the Federal Aviation Administration as experimental.
“Experimental registration of an aircraft typically carries a severe limitation on where the aircraft can be flown and under what conditions that flight can be performed,” Ditchey said.
There are only 83 Cozy Mark IV aircraft registered with the FAA, all classified as experimental due to their housing construction. It was not immediately clear how many other “amateur-built” aircraft are currently registered.
The plane that crashed was registered in August by an Oakland-based company, Winged Wallabies Inc. The Times was unable to identify anyone affiliated with that company.
Ditchey said he would not assume that the construction of the plane caused its fatal flight this week. If he had to guess (based solely on his experience in the field, not direct knowledge of this case), he said it was most likely an engine problem.
“It probably has something to do with a power outage or loss of power, and the motor is not self-made,” he said. “There could be a builder's issue with how the plane was assembled, but that would really be a one-time thing.”
He noted that the plane was seen traveling erratically before going into a nosedive.
“There may be a relationship between the plane's erratic maneuvers and the loss of power,” he said.
Witnesses reported seeing the plane flying erratically before disappearing from sight, prompting a search Sunday night. But that effort was called off early Monday after searchers were unable to locate any of the passengers.
Willmer-Shiles' body was later spotted by a commercial fishing boat and parts of the plane were found washed ashore, local officials said.
If the engine is recovered, Ditchey said investigators will be able to determine whether a power problem was to blame, but other potential problems, including construction flaws, would be more difficult to discern given the severe damage to the plane.
Sulick said the NTSB's preliminary report should be ready in two to three weeks. But the release of a final report, which will include the probable cause of the accident, could take up to two years.
Ditchey said there is less urgency for responses in more isolated situations like these, unlike problems that potentially affect larger commercially built fleets, such as the in-flight explosion of a door plug on a Boeing 737 Max 9 operated by Alaska Airlines. earlier this month.
