# NTSB CHI69F0521: Bensen B-8M, N1173, Lacon, IL, February 28, 1969

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Closed
- Date: February 28, 1969
- Place: Lacon, IL · LACON, IL
- Location: 41.0229° N, 89.4063° W: Placed by OpenAirDocs: center of Lacon, IL, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=41.0229&lon=-89.4063&mi=10
- Phase of flight: [Uncontrolled descent](https://openairdocs.org/ntsb-phases/650) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious
- Status: Completed, report May 19, 1969
- Report: Brief approved by the director
- NTSB case key (mKey): 190892
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI69F0521
- Page: https://openairdocs.org/ntsb/CHI69F0521

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-0528  69/2/28    LACON,ILL           BENSEN B-8M         CR-  0  1  0  INSTRUCTIONAL             STUDENT, AGE 41, 263
        TIME - 1550                    N1173               PX-  0  0  0  TRAINING                  TOTAL HOURS, 50 IN TYPE,
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            NOT INSTRUMENT RATED.
        NAME OF AIRPORT - MARSHALL
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           COLLISION WITH GROUND/WATER: UNCONTROLLED                IN FLIGHT: UNCONTROLLED DESCENT
        PROBABLE CAUSE(S)
           ROTORCRAFT - FLIGHT CONTROL SYSTEMS: CYCLIC PITCH CONTROL SYSTEM
           MISCELLANEOUS ACTS,CONDITIONS - MATERIAL FAILURE
        FACTOR(S)
           MISCELLANEOUS ACTS,CONDITIONS - VIBRATION,EXCESSIVE
           MISCELLANEOUS ACTS,CONDITIONS - OVERLOAD FAILURE
        REMARKS- PUSH PULL TUBE IN CONTROL SYSTEM FAILED AT BRAZED POINT.PRIOR VIBRATIONS CAUSED HIGH LOADS ON TUBE
```

## Aircraft

- Registration: [N1173](https://openairdocs.org/deregistered/N1173-1971-08-04), registration cancelled 1971-08-04, S/N JK-1 (OpenAirDocs)
- Reported make and model: BENSEN B-8M
- Registry model: [Benson Gyroplane B8M](https://openairdocs.org/model/benson-gyroplane-b8m) (registry code 05636B7) (OpenAirDocs)
- Category: Gyroplane, amateur-built
- Engines: reciprocating
- Damage: Substantial damage
- Airport: Marshall

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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