# Accident 20170104000989A: Schosanski John H COZY MK IV R, Napa, CA, January 4, 2017

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: January 4, 2017, 15:00 local time
- Place: Napa, CA
- Damage: Substantial damage
- Phase of flight: Landing: Approach
- Operating rules: General operating rules (Part 91)
- Location: 38.2089° N, 122.2900° W: From the FAA
- Nearby events: https://openairdocs.org/map.md?lat=38.2089&lon=-122.2900&mi=10
- Aircraft: N4518S, registered now (https://openairdocs.org/aircraft/N4518S) (OpenAirDocs)
- Registry model: Schosanski John H COZY MK IV R (registry code 056307Q, https://openairdocs.org/model/schosanski-john-h-cozy-mk-iv-r) (OpenAirDocs)
- Registry engine: Mazda 13B (registry code 43201, https://openairdocs.org/engine/mazda-13b) (OpenAirDocs)
- Reported make and model: SCHOSANSKI JOHN H COZY MK IV R
- Reported engine: MAZDA 13B
- People aboard: 1
- Fatal injuries: 0
- Other injuries: 0
- NTSB investigation: [NTSB WPR17LA048](https://openairdocs.org/ntsb/WPR17LA048) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/20170104000989A

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

ON JANUARY 4, 2017, ABOUT 1430, AN EXPERIMENTAL AMATEUR-BUILT SCHOSANSKI, COZY MK IV R AIRPLANE, N4518S, EXPERIENCED A TOTAL LOSS OF ENGINE POWER AFTER AN ATTEMPTED GO-AROUND DURING A TOUCH-AND-GO LANDING AT NAPA COUNTY AIRPORT (APC), NAPA, CALIFORNIA. THE PILOT SUBSEQUENTLY MADE A FORCED LANDING A MARSH SHORT OF THE RUNWAY.  THE AIRPLANE WAS REGISTERED AND OPERATED BY THE ^PRIVACY DATA OMITTED^PILOT. THE COMMERCIAL RATED PILOT WAS NOT INJURED. THE AIRPLANE SUSTAINED SUBSTANTIAL DAMAGE TO THE LEFT WING. THE LOCAL PERSONAL FLIGHT DEPARTED NAPA, CALIFORNIA, ABOUT 1400 PST. VISUAL METEOROLOGICAL CONDITIONS PREVAILED AND NO FLIGHT PLAN WAS FILED.

THE PILOT REPORTED THAT HE WAS IN THE TRAFFIC PATTERN PERFORMING TOUCH-AND-GO LANDINGS ON RUNWAY 24. DURING APPROACH, THE PILOT NOTED THAT THE AIRPLANE WOULD HAVE LANDED FURTHER DOWN THE RUNWAY THAN DESIRED AND HE INITIATED A GO-AROUND. AS HE ADVANCED THE THROTTLE, THE ENGINE RESPONDED NORMALLY, BUT THEN ROLLED BACK TO IDLE. THE PILOT MADE A FORCED LANDING IN MARSH AREA ¼ MILE PAST THE END OF RUNWAY 24. THE AIRCRAFT CAME TO REST IN A SHALLOW DRAINAGE CANAL. THE AIRPLANE WAS POWERED BY AN AUTOMOTIVE MAZDA ROTARY ENGINE, WHICH WAS MODIFIED BY THE OWNER. THE AIRPLANE WAS RECOVERED FOR FURTHER EXAMINATION. THE OWNER DETERMINED THE LOSS OF POWER WAS DUE TO THE FAILURE OF THE APEX ROTARY PISTON SEAL CREATING A LOSS OF POWER. THE MAZDA 13B AUTOMOTIVE ENGINE WAS BELIEVED TO BE MANUFACTURED IN 1991 THE AIRCRAFT OWNER/BUILDER PERCHED IT USED AND HAS NO IDEA HOW MANY MILES/HOURS IT HAS ACCUMULATED.

## The NTSB's investigation of this event (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB WPR17LA048](https://openairdocs.org/ntsb/WPR17LA048), Jan 4, 2017: Schosanski John H Cozy MK IV R (N4518S), Napa, CA, substantial damage. Probable cause: A partial loss of power due to missing apex seals.

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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