The Airplane Appeared To Increase In Speed, While It Was “Dipping And Turning.”

Location: Half Moon Bay, CA Accident Number: WPR24FA073
Date & Time: January 14, 2024, 19:05 Local Registration: N656TE
Aircraft: Ostroth Thane L Cozy MK IV Injuries: 4 Fatal
Flight Conducted Under: Part 91: General aviation - Personal

On January 14, 2024, about 1905 Pacific standard time, an experimental amateur-built Cozy MK IV, N656TE, was destroyed when it was involved in an accident near Half Moon Bay, California. The pilot and 2 passengers were fatally injured, and 1 passenger is missing and presumed to be fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

Multiple witnesses in the area reported hearing the airplane flying near their location. One witness reported that while dining outside, north of the Half Moon Bay Airport (HAF), they heard the airplane, and saw it shortly after. The witness said that the sound of the engine was similar to the sound of coughing, and that the airplane appeared to increase in speed, while it was “dipping and turning.” The witness stated that the engine “cut out” and the airplane appeared to have banked toward the shoreline. Shortly thereafter they lost visual sight of the airplane’s lights.

Review of preliminary Automatic Dependent Surveillance-Broadcast (ADS-B) derived data provided by commercially available source, showed that the airplane departed runway 30 at HAF and enter a left turn just beyond the departure end of the runway. The ADS-B data showed that the airplane had ascended to a maximum altitude of 250 ft mean sea level, with groundspeeds fluctuating between 91 and 87 knots. The last recorded data point was recorded about 4,900 ft north of where wreckage was observed floating in the Pacific Ocean. 

Sections of wreckage, to include fragments of fiberglass, the center fuselage, canopy, engine, and propeller washed on shore about 2,130 ft west of HAF. The wreckage was recovered to a secure location for further examination.

FMI: www.ntsb.gov