# NTSB CHI65A0069: Boeing B-720B, N725US, Chicago, IL, January 23, 1965

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Closed
- Date: January 23, 1965
- Place: Chicago, IL · CHICAGO, IL
- Location: 41.8500° N, 87.6501° W: Placed by OpenAirDocs: center of Chicago, IL, within about 9 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=41.8500&lon=-87.6501&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 2 serious, 5 minor, 43 uninjured
- Status: Completed
- Report: Brief approved by the director
- NTSB case key (mKey): 180439
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI65A0069
- Page: https://openairdocs.org/ntsb/CHI65A0069

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
1-0050  65/1/23  NR.CHICAGO ILL        BOEING B-720B       CR-  0  0  7  SCHED DOM PASSG SRV       AIRLINE TRANSPORT, AGE
        TIME - 1150                    N725US              PX-  0  2 41                            51, 21893 TOTAL HOURS,
                                       DAMAGE-NONE         OT-  0  0  0                            2631 IN TYPE, INSTRUMENT
                                                                                                   RATED.
        OPERATOR - NORTHWEST AIRLINES,INC.
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           TURBULENCE                                               IN FLIGHT: DESCENDING
        PROBABLE CAUSE(S)
           WEATHER - TURBULENCE IN FLIGHT,CLEAR AIR
           WEATHER - TURBULENCE, ASSOCIATED W/CLOUDS AND/OR THUNDERSTORMS
           PERSONNEL - WEATHER PERSONNEL: INCORRECT WEATHER FORECAST
           PERSONNEL - DISPATCHING (AIR CARRIER ONLY): OTHER
        FACTOR(S)
           MISCELLANEOUS ACTS,CONDITIONS - SEAT BELT SIGN OFF
           MISCELLANEOUS ACTS,CONDITIONS - CIRCUIT BREAKER POPPED
        WEATHER BRIEFING - COMPANY DISPATCH
        WEATHER FORECAST - WEATHER CONSIDERABLY WORSE THAN FORECAST
        SKY CONDITION                                            CEILING AT ACCIDENT SITE
          OVERCAST                                                  400
        VISIBILITY AT ACCIDENT SITE                              PRECIPITATION AT ACCIDENT SITE
          2 MILES OR LESS                                           RAIN SHOWERS, SNOW SHOWERS
        OBSTRUCTIONS TO VISION AT ACCIDENT SITE                  TEMPERATURE-F
          FOG                                                       31
        WIND DIRECTION-DEGREES                                   WIND VELOCITY-KNOTS
          220                                                       141
        TYPE OF WEATHER CONDITIONS                               TYPE OF FLIGHT PLAN
          IFR                                                      IFR
        REMARKS- SEAT BELT SIGN DID NOT STAY ON DUE TO TRIPPED CIRCUIT BREAKER-WX BUR AND CO TURBUL FRCSTS INACCUR
```

## Aircraft

- Registration: [N725US](https://openairdocs.org/deregistered/N725US-1972-04-05), registration cancelled 1972-04-05, S/N 18355 (OpenAirDocs)
- Reported make and model: BOEING B-720B
- Registry model: [Boeing 720-B](https://openairdocs.org/model/boeing-720-b) (registry code 1383804) (OpenAirDocs)
- Category: Airplane
- Engines: turbo fan
- Damage: No 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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.