# NTSB DEN70DXD45: Alon A2-A, N5468F, Boulder, CO, June 10, 1970

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Closed
- Date: June 10, 1970
- Place: Boulder, CO · BOULDER, CO
- Location: 40.0244° N, 105.2513° W: Placed by OpenAirDocs: center of Boulder, CO, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=40.0244&lon=-105.2513&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report March 29, 1971
- Report: Brief approved by the director
- NTSB case key (mKey): 124795
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN70DXD45
- Page: https://openairdocs.org/ntsb/DEN70DXD45

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-2511  70/6/10    BOULDER,COLO        ALON A2-A           CR-  0  0  2  INSTRUCTIONAL             ATP,FLIGHT INSTR., AGE
        TIME - 1045                    N5468F              PX-  0  0  0  DUAL                      36, 8550 TOTAL HOURS, 40
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            IN TYPE, INSTRUMENT
                                                                                                   RATED.
        NAME OF AIRPORT - BOULDER
        DEPARTURE POINT             INTENDED DESTINATION
          BROOMFIELD,COLO             BOULDER,COLO
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           ENGINE FAILURE OR MALFUNCTION                            TAKEOFF: INITIAL CLIMB
           COLLIDED WITH: DIRT BANK                                 LANDING: ROLL
        PROBABLE CAUSE(S)
           POWERPLANT - ENGINE STRUCTURE: VALVE ASSEMBLIES
           MISCELLANEOUS ACTS,CONDITIONS - MATERIAL FAILURE
        PARTIAL POWER LOSS - PARTIAL LOSS OF POWER - 1 ENGINE
        EMERGENCY CIRCUMSTANCES - FORCED LANDING OFF AIRPORT ON LAND
        REMARKS- NR 2 EXHAUST VALVE SEPARATED AT BASE OF HEAD.
```

## Aircraft

- Registration: [N5468F](https://openairdocs.org/deregistered/N5468F-1971-04-13), registration cancelled 1971-04-13, S/N B-268 (OpenAirDocs)
- Reported make and model: ALON A2-A
- Registry model: [Alon A-2A](https://openairdocs.org/model/alon-a-2a) (registry code 0540104) (OpenAirDocs)
- Category: Airplane
- Engines: reciprocating
- Damage: Substantial damage
- Airport: Boulder

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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