# NTSB OAK67A0057: Piper PA-23, N4925P, San Mateo, CA, January 19, 1967

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Closed
- Date: January 19, 1967
- Place: San Mateo, CA · SAN MATEO, CA
- Location: 37.5603° N, 122.3106° W: Placed by OpenAirDocs: center of San Mateo, CA, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=37.5603&lon=-122.3106&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed, report June 6, 1967
- Report: Brief approved by the director
- NTSB case key (mKey): 119161
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=OAK67A0057
- Page: https://openairdocs.org/ntsb/OAK67A0057

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
2-0221  67/1/19    SAN MATEO CALIF     PIPER PA-23         CR-  1  0  0  NONCOMMERCIAL             PRIVATE, AGE 37, UNK/NR
        TIME - 0118                    N4925P              PX-  1  0  0  BUSINESS                  TOTAL HOURS, UNK/NR IN
                                       DAMAGE-DESTROYED    OT-  0  0  0                            TYPE, NOT INSTRUMENT
                                                                                                   RATED.
        NAME OF AIRPORT - SAN FRANCISCO
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           ENGINE FAILURE OR MALFUNCTION                            IN FLIGHT: NORMAL CRUISE
           COLLISION WITH GROUND/WATER: UNCONTROLLED                LANDING: FINAL APPROACH
        PROBABLE CAUSE(S)
           POWERPLANT - ENGINE STRUCTURE: PISTON,PISTON RINGS
           POWERPLANT - ENGINE STRUCTURE: VALVE ASSEMBLIES
           MISCELLANEOUS ACTS,CONDITIONS - MATERIAL FAILURE
           PILOT IN COMMAND - ATTEMPTED OPERATION BEYOND EXPERIENCE/ABILITY LEVEL
           PILOT IN COMMAND - IMPROPER IFR OPERATION
        FACTOR(S)
           WEATHER - LOW CEILING
           WEATHER - FOG
           MISCELLANEOUS ACTS,CONDITIONS - AIRCRAFT CAME TO REST IN WATER
        COMPLETE POWER LOSS - COMPLETE ENGINE FAILURE/FLAMEOUT-1 ENGINE
        WEATHER BRIEFING - BRIEFED BY FLIGHT SERVICE PERSONNEL, BY RADIO
        WEATHER FORECAST - FORECAST SUBSTANTIALLY CORRECT
        EMERGENCY CIRCUMSTANCES - PRECAUTIONARY LANDING ON AIRPORT
                                  ADVERSE/UNFAVORABLE WEATHER
                                  SUSPECTED MECHANICAL DISCREPANCY
        SKY CONDITION                                            CEILING AT ACCIDENT SITE
          OBSCURATION                                              UNKNOWN/NOT REPORTED
        VISIBILITY AT ACCIDENT SITE                              PRECIPITATION AT ACCIDENT SITE
          2 MILES OR LESS                                          NONE
        OBSTRUCTIONS TO VISION AT ACCIDENT SITE                  TEMPERATURE-F
          GROUND FOG                                                41
        WIND DIRECTION-DEGREES                                   WIND VELOCITY-KNOTS
           30                                                       5
        TYPE OF WEATHER CONDITIONS                               TYPE OF FLIGHT PLAN
          IFR                                                      IFR
        REMARKS- NO.2 PISTON AND EXHAUST VALVE, RT ENGINE, FAILED. NON-INST RATED PLT.
```

## Aircraft

- Registration: [N4925P](https://openairdocs.org/deregistered/N4925P-1967-11-09), registration cancelled 1967-11-09, S/N 27-517 (OpenAirDocs)
- Reported make and model: PIPER PA-23
- Registry model: [Piper PA-23-235](https://openairdocs.org/model/piper-pa-23-235) (registry code 7102306) (OpenAirDocs)
- Category: Airplane
- Engines: reciprocating
- Damage: Destroyed
- Airport: San Francisco

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.

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