# NTSB SEA69F0217: Brantly B-2B, N2186U, Lodge Grass, MT, April 23, 1969

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Closed
- Date: April 23, 1969
- Place: Lodge Grass, MT · LODGE GRASS, MT
- Location: 45.3143° N, 107.3678° W: Placed by OpenAirDocs: center of Lodge Grass, MT, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=45.3143&lon=-107.3678&mi=10
- Phase of flight: [Uncontrolled descent](https://openairdocs.org/ntsb-phases/650) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report June 24, 1969
- Report: Brief approved by the director
- NTSB case key (mKey): 189624
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA69F0217
- Page: https://openairdocs.org/ntsb/SEA69F0217

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-1142  69/4/23    LODGE GRASS,MONT    BRANTLY B-2B        CR-  0  0  1  INSTRUCTIONAL             STUDENT, AGE 44, 58 TOTAL
        TIME - 1855                    N2186U              PX-  0  0  0  TRAINING                  HOURS, ALL IN TYPE, NOT
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            INSTRUMENT RATED.
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           COLLISION WITH GROUND/WATER: UNCONTROLLED                IN FLIGHT: UNCONTROLLED DESCENT
        PROBABLE CAUSE(S)
           PILOT IN COMMAND - FAILED TO MAINTAIN ADEQUATE ROTOR R.P.M.
        FACTOR(S)
           WEATHER - DOWNDRAFT,UPDRAFTS
        WEATHER BRIEFING - NO RECORD OF BRIEFING RECEIVED
        WEATHER FORECAST - UNKNOWN/NOT REPORTED
        SKY CONDITION                                            CEILING AT ACCIDENT SITE
          CLEAR                                                    UNLIMITED
        VISIBILITY AT ACCIDENT SITE                              PRECIPITATION AT ACCIDENT SITE
          5 OR OVER(UNLIMITED)                                     NONE
        OBSTRUCTIONS TO VISION AT ACCIDENT SITE                  TEMPERATURE-F
          NONE                                                      65
        WIND DIRECTION-DEGREES                                   WIND VELOCITY-KNOTS
          180                                                       15
        TYPE OF WEATHER CONDITIONS                               TYPE OF FLIGHT PLAN
          VFR                                                      NONE
        REMARKS- DOWNDRAFTS ON DOWNWIND SIDE OF 50 FT HIGH TREES.WINDS 15-20 KTS.
```

## Aircraft

- Registration: [N2186U](https://openairdocs.org/deregistered/N2186U-1970-06-11), registration cancelled 1970-06-11, S/N 348, built 1963 (OpenAirDocs)
- Reported make and model: BRANTLY B-2B
- Registry model: [Brantly B-2B](https://openairdocs.org/model/brantly-b-2b) (registry code 1440506) (OpenAirDocs)
- Category: Helicopter
- Engines: reciprocating
- Damage: 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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