# NTSB OAK77FVM08: Mooney MK20C, N6494U, Half Moon Bay, CA, February 15, 1977

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Closed
- Date: February 15, 1977
- Place: Half Moon Bay, CA · HALF MOON BAY, CA
- Location: 37.4673° N, 122.4399° W: Placed by OpenAirDocs: center of Half Moon Bay, CA, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=37.4673&lon=-122.4399&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report March 22, 1977
- Report: Brief approved by the director
- NTSB case key (mKey): 156825
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=OAK77FVM08
- Page: https://openairdocs.org/ntsb/OAK77FVM08

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-0168  77/2/15    HALF MOON BAY,CA    MOONEY MK20C        CR-  0  0  1  NONCOMMERCIAL             PRIVATE, AGE 43, 489
        TIME - 1400                    N6494U              PX-  0  0  0  PLEASURE/PERSONAL TRANSP  TOTAL HOURS, 446 IN TYPE,
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            NOT INSTRUMENT RATED.
        NAME OF AIRPORT - HALF MOON BAY
        DEPARTURE POINT             INTENDED DESTINATION
          PALO ALTO,CA                HALF MOON BAY,CA
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           GROUND-WATER LOOP-SWERVE                                 TAKEOFF: RUN
           COLLIDED WITH: FENCE,FENCEPOSTS                          TAKEOFF: RUN
        PROBABLE CAUSE(S)
           PILOT IN COMMAND - FAILED TO MAINTAIN DIRECTIONAL CONTROL
           AIRFRAME - LANDING GEAR: NOSEWHEEL STEERING
        FACTOR(S)
           PILOT IN COMMAND - FAILED TO ABORT TAKEOFF
        REMARKS- EXTREME NOSE GEAR SHIMMY CAUSED LOSS OF DIRECTIONAL CONTROL.
```

## Aircraft

- Registration: [N6494U](https://openairdocs.org/deregistered/N6494U-1990-08-17), registration cancelled 1990-08-17, S/N 2241 (OpenAirDocs)
- Reported make and model: MOONEY MK20C
- Registry model: [Mooney M20C](https://openairdocs.org/model/mooney-m20c) (registry code 5870208) (OpenAirDocs)
- Category: Airplane
- Engines: reciprocating
- Damage: Substantial damage
- Airport: Half Moon Bay

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19770215003179A](https://openairdocs.org/incident/19770215003179A), Feb 15, 1977: Mooney M20C, Half Moon Bay, CA, Substantial damage. Extreme nose gear shimmy caused loss of directional control.

## Other investigations on N6494U (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 SEA86LA116](https://openairdocs.org/ntsb/SEA86LA116), May 2, 1986: Mooney M20C (N6494U), Twin Falls, ID, destroyed

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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