# NTSB DCA71AZ009: Boeing 720, N3166, Ontario, CA, March 31, 1971

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Closed
- Date: March 31, 1971
- Place: Ontario, CA · ONTARIO, CA
- Location: 34.0633° N, 117.6509° W: Placed by OpenAirDocs: center of Ontario, CA, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=34.0633&lon=-117.6509&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 5 fatal
- Status: Completed, report September 15, 1972
- Safety recommendations: Yes
- NTSB case key (mKey): 79478
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DCA71AZ009
- Board report AAR7218 (PDF): https://www.ntsb.gov/investigations/AccidentReports/Reports/AAR7218.pdf
- Page: https://openairdocs.org/ntsb/DCA71AZ009-79478

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
1-0002  71/3/31    ONTARIO,CALIF       BOEING 720          CR-  5  0  0  TRAINING                  AIRLINE TRANSPORT, AGE
        TIME - 0633                    N3166               PX-  0  0  0                            49, 19714 TOTAL HOURS,
                                       DAMAGE-DESTROYED    OT-  0  0  0                            3780 IN TYPE, INSTRUMENT
                                                                                                   RATED.
        NAME OF AIRPORT - ONTARIO INTL
        OPERATOR - WESTERN AIR LINES,INC.
        DEPARTURE POINT             INTENDED DESTINATION
          LOS ANGELES,CALIF           LOS ANGELES,CALIF
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           COLLISION WITH GROUND/WATER: UNCONTROLLED                LANDING: MISSED APPROACH
        PROBABLE CAUSE(S)
           SYSTEMS - FLIGHT CONTROL SYSTEMS: RUDDER AND RUDDER TAB CONTROL SYSTEM
           MISCELLANEOUS ACTS,CONDITIONS - MATERIAL FAILURE
        FACTOR(S)
           MISCELLANEOUS ACTS,CONDITIONS - SIMULATED CONDITIONS
           WEATHER - OBSTRUCTIONS TO VISION
           WEATHER - FOG
        WEATHER BRIEFING - COMPANY DISPATCH
        WEATHER FORECAST - FORECAST SUBSTANTIALLY CORRECT
        SKY CONDITION                                            CEILING AT ACCIDENT SITE
          OVERCAST                                                  600
        VISIBILITY AT ACCIDENT SITE                              PRECIPITATION AT ACCIDENT SITE
          3/4 MILE OR LESS                                         NONE
        OBSTRUCTIONS TO VISION AT ACCIDENT SITE                  TEMPERATURE-F
          FOG                                                       51
        WIND DIRECTION-DEGREES                                   WIND VELOCITY-KNOTS
          250                                                       4
        TYPE OF WEATHER CONDITIONS                               TYPE OF FLIGHT PLAN
          IFR                                                      IFR
         FIRE AFTER IMPACT
        REMARKS- RUDDER HYDRAULIC ACTUATOR SUPPORT FITTING,STRESS CORROSION CRACKS.SIM 3-ENG MISSED APCH.
```

## Aircraft

- Registration: [N3166](https://openairdocs.org/deregistered/N3166-1971-03-31), registration cancelled 1971-03-31, S/N 19439, built 1967 (OpenAirDocs)
- Reported make and model: BOEING 720
- Registry model: [Boeing 720-047B](https://openairdocs.org/model/boeing-720-047b) (registry code 1383857) (OpenAirDocs)
- Category: Airplane
- Engines: turbo fan
- Damage: Destroyed
- Airport: Ontario Intl

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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