# NTSB CHI77FEM34: Bell 47D, N64580, Byron Center, MI, July 21, 1977

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Closed
- Date: July 21, 1977
- Place: Byron Center, MI · BYRON CENTER, MI
- Location: 42.8078° N, 85.7267° W: Placed by OpenAirDocs: center of Byron Center, MI, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=42.8078&lon=-85.7267&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious
- Status: Completed, report November 16, 1977
- Report: Brief approved by the director
- NTSB case key (mKey): 146359
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI77FEM34
- Page: https://openairdocs.org/ntsb/CHI77FEM34

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-2238  77/7/21    BYRON CENTER,MI     BELL 47D            CR-  0  1  0  COMMERCIAL                COMMERCIAL, FL.INSTR.,
        TIME - 2030                    N64580              PX-  0  0  0  ASSOC CROP CTL ACTIVITY   AGE 39, 1800 TOTAL HOURS,
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            300 IN TYPE, NOT
                                                                                                   INSTRUMENT RATED.
        DEPARTURE POINT             INTENDED DESTINATION
          BYRON CENTER,MI             LOCAL
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           COLLIDED WITH: BUILDING(S)                               TAKEOFF: VERTICAL
        PROBABLE CAUSE(S)
           PILOT IN COMMAND - FAILED TO MAINTAIN ADEQUATE ROTOR R.P.M.
         SPECIAL DATA
          TOTAL HOURS IN CROP CONTROL -  500                       KIND OF OPERATION - FERTILIZING (LIQUID)
          KIND OF CROP - CORN                                      TYPE OF CHEMICAL USED - DRY CHEMICAL-NONTOXIC
          PILOT' S SEAT BELT -FASTENED-PROPERLY                    GLOVES - NOT USED
          GOGGLES - NOT USED                                       CRASH HELMET - AVAILABLE-NOT USED
          COCKPIT CRASHPAD - INSTALLED                             CRASH BAR - INSTALLED
          TANK/HOPPER-LOCATION - SIDES                             TERRAIN-TYPE -LEVEL,FLAT
          ELEVATION-AREA BEING TREATED-FEET -  630
```

## Aircraft

- Registration: [N64580](https://openairdocs.org/deregistered/N64580-2017-07-20), registration cancelled 2017-07-20, S/N TWH-9, built 1977 (OpenAirDocs)
- Reported make and model: BELL 47D
- Registry model: [Bell-Transworld Helicopters 47D1](https://openairdocs.org/model/bell-transworld-helicopters-47d1) (registry code 1180845) (OpenAirDocs)
- Registry engine: [Franklin 6A&6V335 series](https://openairdocs.org/engine/franklin-6a-6v335-series) (registry code 27020, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Engines: reciprocating
- Damage: Substantial damage
- Airport: Farm Pad

## 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 19770721019199A](https://openairdocs.org/incident/19770721019199A), Jul 21, 1977: Bell 47D1, Byron Center, MI, Substantial damage

## Other investigations on N64580 (3)

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 LAX03CA274](https://openairdocs.org/ntsb/LAX03CA274), Sep 2, 2003: Bell 47D1 (N64580), Chino, CA, substantial damage. Probable cause: the student pilot's inappropriate remedial action through the application of excessive aft cyclic during a run-on landing. A factor in the accident was the student's disregard for company procedures.
- [NTSB LAX01FA236](https://openairdocs.org/ntsb/LAX01FA236), Jul 6, 2001: Bell 47D-1 (N64580), Riverside, CA, substantial damage. Probable cause: The engine crankshaft's failure as the result of fatigue cracking initiated by surface damage and localized overheating due to the installation at overhaul of incorrectly sized bearings.
- [NTSB CHI79FEM21](https://openairdocs.org/ntsb/CHI79FEM21), May 19, 1979: Bell 47D-1 (N64580), Middleville, MI, substantial damage

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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