Boeing 767-231 incident near Knox, Indiana, September 5, 1989
On September 5, 1989 at about 9:52 pm local time, a Boeing 767-231, registered N608TW, was involved in an incident near Knox, Indiana. It was a flight of an unrecorded kind under scheduled airline rules (Part 121). 6 people had minor injuries; 156 others were unhurt. The weather was instrument conditions (cloud, fog or low visibility).
The NTSB's probable cause their words, unchanged
THE RADAR CONTROLLLER'S FAILURE TO MAINTAIN RADAR SEPARATION. FACTORS CONTRIBUTING TO THE INCIDENT WERE: MISUNDERSTANDING OF AN ATC INSTRUCTION BY THE PILOT OF THE INCIDENT AIRPLANE, AND UNCLEAR PHRASEOLOGY USED IN THE INSTRUCTIONS ISSUED BY THE RADAR CONTROLLER.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 5, 1989 · about 9:52 pm local time
- Place
- Knox, Indiana · map
- Type
- Incident
- Injuries
- 6 people had minor injuries; 156 others were unhurt.
- Weather
- instrument conditions (cloud, fog or low visibility)
- Aircraft
- Boeing 767-231 · all 767-231s on the register
- Registration
- N608TW · no longer on the register
- Damage
- Not recorded
- Flight
- Flight of an unrecorded kind · scheduled airline rules (Part 121)
The NTSB's narrative final · quoted from the NTSB record
THIS AIRPLANE WAS INVOLVED IN A NEAR COLLISION WITH ANOTHER AIRPLANE WHILE IN POSITIVE CONTROL AIRSPACE. BOTH AIRPLANES TOOK EVASIVE ACTION. VISIBILITY WAS REPORTED BY BOTH FLIGHT CREWS AS BEING REDUCED BY THE PRESENCE OF CIRRUS CLOUDS WITH NO VISIBLE HORIZON. THIS AIRPLANE HAD ACKNOWLEDGED AND RESPONDED TO A TURN INSTRUCTION ISSUED TO A THIRD AIRPLANE WITH A SIMILAR CALL SIGN, AND TURNED TO A HEADING WHICH PUT THE TWO INVOLVED AIRPLANES ON AN INTERSECTING COURSE. THE TURN INSTRUCTION WAS CHALLENGED BY THE AIRPLANE FOR WHOM IT WAS INTENDED, BUT THE INCIDENT AIRPLANE WAS NEVER TURNED BACK TO ITS ORIGINAL HEADING. THE ERROR WAS DISCOVERED A SHORT TIME LATER BY THE MANUAL CONTROLLER AND POINTED OUT TO THE RADAR CONTROLLER. HE ISSUED TURN AND CLIMB INSTRUCTIONS TO THE INCIDENT AIRPLANE ALONG WITH A TRAFFIC ADVISORY. CORRELATION OF THE TWO DFDR READOUTS WITH RADAR TRACK DATA SHOW, THAT AT THE POINT OF CLOSEST APPROACH, VERTICAL SEPARATION WAS BETWEEN 95 AND 200 FT.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: airline transport pilot
- Ratings: multi-engine land; instrument: airplane
- Medical certificate: Class 1
- Seat: unk
The aircraft
- Last inspection: inspection type not recorded; 0 hours since
- Maximum gross weight: 300,000 lb
- Landing gear: retractable
- Engine: P&W JT9D-7R4D (turbofan); 0 hours total
- Operator: Trans World Airlines INC.
The flight
- Departed from: STL St Louis MO
- Destination: Paris, France OF
- Flight plan: IFR
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Sky: not recorded; not recorded
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | 10 | ||
| Passengers | 5 | 146 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.