# NTSB UNK64X3669: Piper J3C, N70399, Tewksbury, MA, August 29, 1964

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Closed
- Date: August 29, 1964
- Place: Tewksbury, MA · TEWKSBURY, MA
- Location: 42.6106° N, 71.2342° W: Placed by OpenAirDocs: center of Tewksbury, MA, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=42.6106&lon=-71.2342&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report November 4, 1964
- Report: Brief approved by the director
- NTSB case key (mKey): 181979
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=UNK64X3669
- Page: https://openairdocs.org/ntsb/UNK64X3669

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-2683  64/8/29    TEWKSBURY MASS      PIPER J3C           CR-  0  0  1  NONCOMMERCIAL             PRIVATE, AGE 39, 25 TOTAL
        TIME - 1530                    N70399              PX-  0  0  1  PLEASURE/PERSONAL TRANSP  HOURS, 15 IN TYPE, NOT
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            INSTRUMENT RATED.
        NAME OF AIRPORT - TEWKSBURY
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           ENGINE FAILURE OR MALFUNCTION                            LANDING: TRAFFIC PATTERN-CIRCLING
           GEAR COLLAPSED                                           LANDING: ROLL
        PROBABLE CAUSE(S)
           POWERPLANT - ENGINE STRUCTURE: VALVE ASSEMBLIES
           MISCELLANEOUS ACTS,CONDITIONS - MATERIAL FAILURE
        FACTOR(S)
           MISCELLANEOUS ACTS,CONDITIONS - OVERLOAD FAILURE
        PARTIAL POWER LOSS - PARTIAL LOSS OF POWER - 1 ENGINE
        EMERGENCY CIRCUMSTANCES - FORCED LANDING OFF AIRPORT ON LAND
        REMARKS- EXHAUST VALVE BROKE OFF BELOW HEAD.
```

## Aircraft

- Registration: N70399 (not matched to a registry record)
- Reported make and model: PIPER J3C
- Category: Airplane
- Engines: reciprocating
- Damage: Substantial damage
- Airport: Tewksbury

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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