# NTSB OAK76FVG02: Bell 47G-2, N988B, Napa, CA, July 2, 1975

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Closed
- Date: July 2, 1975
- Place: Napa, CA · NAPA, CA
- Location: 38.2971° N, 122.3010° W: Placed by OpenAirDocs: center of Napa, CA, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=38.2971&lon=-122.3010&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report August 29, 1975
- Report: Brief approved by the director
- NTSB case key (mKey): 149851
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=OAK76FVG02
- Page: https://openairdocs.org/ntsb/OAK76FVG02

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-2066   75/7/2    NAPA,CA             BELL 47G-2          CR-  1  0  0  COMMERCIAL                COMMERCIAL, AGE 33, 6000
        TIME - 1700                    N988B               PX-  0  0  0  ASSOC CROP CTL ACTIVITY   TOTAL HOURS, 100 IN TYPE,
                                       DAMAGE-DESTROYED    OT-  0  0  0                            INSTRUMENT RATED.
        NAME OF AIRPORT - NAPA ARPT
        DEPARTURE POINT             INTENDED DESTINATION
          NAPA,CA                     LOCAL
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           PROPELLER/ROTOR FAILURE: TAIL ROTOR                      TAKEOFF: VERTICAL
           COLLISION WITH GROUND/WATER: UNCONTROLLED                IN FLIGHT: UNCONTROLLED DESCENT
        PROBABLE CAUSE(S)
           ROTORCRAFT - ROTOR ASSEMBLIES: TAIL ROTOR BLADES
           MISCELLANEOUS ACTS,CONDITIONS - FATIGUE FRACTURE
           PERSONNEL - PRODUCTION-DESIGN-PERSONNEL: SUBSTANDARD QUALITY CONTROL
        FACTOR(S)
           MISCELLANEOUS ACTS,CONDITIONS - SEPARATION IN FLIGHT
         SPECIAL DATA
          TOTAL HOURS IN CROP CONTROL -  105                       KIND OF OPERATION - DUSTING CROPS
          KIND OF CROP - GRAPES                                    TYPE OF CHEMICAL USED - DRY CHEMICAL-NONTOXIC
          PILOT' S SEAT BELT -FASTENED-PROPERLY                    GLOVES - USED
          GOGGLES - NOT USED                                       CRASH HELMET - AVAILABLE USED
          COCKPIT CRASHPAD - NOT INSTALLED                         CRASH BAR - NOT INSTALLED
          TANK/HOPPER-LOCATION - SIDES                             TERRAIN-TYPE -LEVEL,FLAT
          ELEVATION-AREA BEING TREATED-FEET -  50
         FIRE AFTER IMPACT
        REMARKS- IMPROPERLY MACHINED T/R HUB BOLT FAILED. BLADE SEPARATED FROM ROTOR YOKE. PN 47-641-052-3.
```

## Aircraft

- Registration: [N988B](https://openairdocs.org/deregistered/N988B-1975-08-27), registration cancelled 1975-08-27, S/N 1416 (OpenAirDocs)
- Reported make and model: BELL 47G-2
- Registry model: [Bell 47G-2](https://openairdocs.org/model/bell-47g-2) (registry code 1181008) (OpenAirDocs)
- Category: Helicopter
- Engines: reciprocating
- Damage: Destroyed
- Airport: Napa Arpt

## 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 19750702020319A](https://openairdocs.org/incident/19750702020319A), Jul 2, 1975: Bell 47G2, Napa, CA, Destroyed. Improperly machined t/r hub bolt failed. Blade separated from rotor yoke. Pn 47-641-052-3.

## Other investigations on N988B (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 OAK74DVD17](https://openairdocs.org/ntsb/OAK74DVD17), Oct 13, 1973: Bell 47G2 (N988B), Brentwood, CA, 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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