# NTSB DEN76FTM07: Berkshire 70, N4KX, Heber City, UT, September 20, 1975

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Closed
- Date: September 20, 1975
- Place: Heber City, UT · HEBER CITY, UT
- Location: 40.5069° N, 111.4132° W: Placed by OpenAirDocs: center of Heber City, UT, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=40.5069&lon=-111.4132&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed, report November 3, 1975
- Report: Brief approved by the director
- NTSB case key (mKey): 151217
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN76FTM07
- Page: https://openairdocs.org/ntsb/DEN76FTM07

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-3061  75/9/20    HEBER CITY,UT       BERKSHIRE 70        CR-  0  0  1  MISCELLANEOUS             PRIVATE, AGE 26, 182
        TIME - 1415                    N4KX                PX-  0  0  0  AIR SHOW/RACING           TOTAL HOURS, 48 IN TYPE,
                                       DAMAGE-DESTROYED    OT-  0  0  0                            NOT INSTRUMENT RATED.
        NAME OF AIRPORT - HEBER VALLEY
        DEPARTURE POINT             INTENDED DESTINATION
          HEBER CITY,UT               RETURN
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           MISCELLANEOUS                                            IN FLIGHT: OTHER
           COLLISION WITH GROUND/WATER: UNCONTROLLED                IN FLIGHT: UNCONTROLLED DESCENT
        PROBABLE CAUSE(S)
           PILOT IN COMMAND - IMPROPER IN-FLIGHT DECISIONS OR PLANNING
           MISCELLANEOUS ACTS,CONDITIONS - FLUTTER
        FACTOR(S)
           WEATHER - TURBULENCE IN FLIGHT,CLEAR AIR
           MISCELLANEOUS ACTS,CONDITIONS - VIBRATION,EXCESSIVE
        WEATHER BRIEFING - NO RECORD OF BRIEFING RECEIVED
        WEATHER FORECAST - UNKNOWN/NOT REPORTED
        SKY CONDITION                                            CEILING AT ACCIDENT SITE
          SCATTERED                                                UNLIMITED
        VISIBILITY AT ACCIDENT SITE                              PRECIPITATION AT ACCIDENT SITE
          5 OR OVER(UNLIMITED)                                     NONE
        OBSTRUCTIONS TO VISION AT ACCIDENT SITE                  TEMPERATURE-F
          NONE                                                      60
        TYPE OF WEATHER CONDITIONS                               TYPE OF FLIGHT PLAN
          VFR                                                      NONE
        REMARKS- GLIDER FLOWN AT REDLINE AIRSPEED.AERODYNAMIC FLUTTER OCCURRED.PLT PARACHUTED OK.
```

## Aircraft

- Registration: [N4KX](https://openairdocs.org/deregistered/N4KX-1975-11-14), registration cancelled 1975-11-14, S/N 4, built 1972 (OpenAirDocs)
- Reported make and model: BERKSHIRE 70
- Registry model: [Berkshire Mfg. CONCEPT 70](https://openairdocs.org/model/berkshire-mfg-concept-70) (registry code 1240104) (OpenAirDocs)
- Category: Glider
- Engines: none
- Damage: Destroyed
- Airport: Heber Valley

## 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 19750920031729A](https://openairdocs.org/incident/19750920031729A), Sep 20, 1975: Amtr 1100110, Heber City, UT, Destroyed. Glider flown at redline airspeed. Aerodynamic flutter occurred. Plt parachuted ok.

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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