Amateur-built COZY MK IV accident near Half Moon Bay, California, January 15, 2024
On January 15, 2024 at about 3:05 am local time, a 2007 amateur-built COZY MK IV, registered N656TE, was destroyed in an accident during initial climb near Half Moon Bay, California (Half Moon Bay airport). It was a personal flight under general aviation rules (Part 91). 4 people were killed. The weather was instrument conditions (cloud, fog or low visibility).
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The NTSB's probable cause their words, unchanged
The airplane’s impact with the ocean for undetermined reasons after departing into night, instrument meteorological conditions.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- January 15, 2024 · about 3:05 am local time
- Place
- Half Moon Bay, California · Half Moon Bay · map
- Type
- Accident
- Injuries
- 4 people were killed.
- Weather
- instrument conditions (cloud, fog or low visibility)
- Aircraft
- Amateur-built COZY MK IV, built 2007
- Registration
- N656TE · registry record · serial 001
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot departed under visual flight rules while instrument meteorological conditions were reported at the airport, with a broken cloud layer at 300 ft above ground level (agl). A witness who was dining outside north of the departure airport initially 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 dipped and turned. The sound of the engine then “cut out,” and the airplane appeared to have banked toward the shoreline. Shortly thereafter the witness lost sight of the airplane’s lights. Flight track data showed that the airplane departed to the north and entered a left turn just beyond the departure end of the runway. The data showed that the airplane had ascended to a maximum altitude of 250 ft mean sea level (msl), with groundspeed fluctuating between 87 and 91 knots. The last data point was recorded about 4,900 ft north of where wreckage was observed floating in the Pacific Ocean. Postaccident examination of the airplane revealed that the fuel lines attached to the fuel flow divider remained attached but were loose when moved with a wrench. No evidence of fuel staining or leaks was observed. Postaccident examination of the airplane revealed no other evidence of a potential mechanical malfunction that would have precluded normal operation.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Unknown or undetermined during initial climb defining event
- Collision with terrain or object (not controlled flight into terrain) during initial climb
The NTSB's findings
- Not determined › Not determined › (general) › (general) › Unknown/Not determined
Pilot
- Certificate: flight instructor, commercial pilot, remote
- Ratings: multi-engine land; single-engine land; single-engine sea; instructor: airplane single-engine; instructor: helicopter; instrument: airplane; rotorcraft: glider; rotorcraft: helicopter
- Flight time: 2,549 hours in all; 207.5 in this make and model; 36.9 in the last 30 days
- Medical certificate: Class 1 (with waivers/limitations)
- Seat: unk
- Injury: fatal
The aircraft
- Seats: 4
- Landing gear: retractable
- Engine: Superior IO-360 (piston); 0 hours total
The flight
- Destination: Hayward CA
Weather at the time
- Light: night
- Wind: from 020° at 5 knots
- Visibility: 5 statute miles
- Sky: broken clouds at 300 ft
- Temperature: 48°F (9°C), dew point 48°F (9°C)
- Altimeter: 30.11 inHg
- Observation at 7:04 pm from KHAF, 1 miles away
Weather report (METAR): KHAF 150315Z AUTO 02005KT 5SM BR BKN003 09/09 A3011 RMK AO2
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 3 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
22 documents, released by the NTSB on February 11, 2026. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number WPR24FA073.