# NTSB CHI71AC031: Dehavilland DHC-6, N956SM, Lacrosse, WI, November 9, 1970

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Closed
- Date: November 9, 1970
- Place: Lacrosse, WI · LACROSSE, WI
- Location: 43.8251° N, 91.2246° W: Placed by OpenAirDocs: center of La Crosse, WI, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=43.8251&lon=-91.2246&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 5 serious, 1 minor
- Status: Completed, report May 5, 1971
- Report: Brief approved by the director
- Safety recommendations: Yes
- NTSB case key (mKey): 79653
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI71AC031
- Page: https://openairdocs.org/ntsb/CHI71AC031

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-1452   70/11/9   LACROSSE,WIS        DEHAVILLAND DHC-6   CR-  0  2  0  COMMERCIAL                ATP,FLIGHT INSTR., AGE
        TIME - 1608                    N956SM              PX-  0  3  1  COMMUTER AIR CARRIER      27, 2350 TOTAL HOURS, 920
                                       DAMAGE-DESTROYED    OT-  0  0  0  AIR TAXI-PASSG S-D        IN TYPE, INSTRUMENT
                                                                                                   RATED.
        NAME OF AIRPORT - LACROSSE MUN.
        DEPARTURE POINT             INTENDED DESTINATION         LAST ENROUTE STOP
          MINNEAPOLIS,MINN            CHICAGO,ILL                  LACROSSE,WIS
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           COLLIDED WITH: TREES                                     LANDING: FINAL APPROACH
        PROBABLE CAUSE(S)
          PILOT-CAPT FAILED TO MAINT ALT AT MDA,REASONS UNKN
           PILOT IN COMMAND - IMPROPER IFR OPERATION
        REMARKS- IFR NON-PRECISION APCH,DSCNDD BLO TREE HEIGHT.
```

## Aircraft

- Registration: [N956SM](https://openairdocs.org/deregistered/N956SM-1971-01-28), registration cancelled 1971-01-28, S/N 203 (OpenAirDocs)
- Reported make and model: DEHAVILLAND DHC-6
- Registry model: [Dehavilland DHC-6 TWIN OTTER](https://openairdocs.org/model/dehavilland-dhc-6-twin-otter) (registry code 2802606) (OpenAirDocs)
- Category: Airplane
- Engines: turbo prop
- Damage: Destroyed
- Airport: Lacrosse Mun.

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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