Amateur-built SD360 incident near Chicago, Illinois, March 8, 1989
On March 8, 1989, a amateur-built SD360, registered N366MQ, was involved in an incident near Chicago, Illinois (O'Hare Intl airport). It was a flight of an unrecorded kind under scheduled airline rules (Part 121). No one was hurt; 37 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE PIC FOLLOWED A CLEARANCE INTENDED FOR ANOTHER AIRPLANE.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 8, 1989
- Place
- Chicago, Illinois · O'Hare Intl
- Type
- Incident
- Injuries
- No one was hurt; 37 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built SD360
- Registration
- N366MQ · registry record · serial SH 3639
- Damage
- Not recorded
- Flight
- Flight of an unrecorded kind · scheduled airline rules (Part 121)
The NTSB's narrative final · quoted from the NTSB record
THE LOCAL CONTROLLER POSITIONED SIMMONS 4058 ON RWY 9L FIRST, AND THEN POSITIONED SIMMONS 4158 (THIS AIRPLANE) ON RWY 4L. HE THEN RETURNED TO SIMMONS 4058, STATED THE RWY NUMBER, & CLEARED IT FOR TAKEOFF. BEFORE SIMMONS 4058 HAD A CHANCE TO REPLY, SIMMONS 4158 (THIS AIRPLANE) ACKNOWLEDGED THE CLEARANCE. SIMMONS 4058 QUERIED THE CLEARANCE. REALIZING THE CONFUSION, AND SEEING SIMMONS 4158 (THIS AIRPLANE) MOVING, THE CONTROLLER CANCELED SIMMONS 4058 TAKEOFF CLEARANCE. SIMMONS 4058 REPLIED 'WE THOUGHT THAT WAS GONNA HAPPEN'. A PILOT 'SLOWDOWN' WAS TAKING PLACE AT THE TIME, AND THE CONTROLLERS STATED THAT PILOTS WERE TAXIING MORE SLOWLY THAN USUAL AND APPEARED TO GET LOST OR CONFUSED ON THE GROUND MORE OFTEN. THE CREW OF SIMMONS 4158 VEHEMENTLY DENIED PARTICIPATION IN THE UNION-RELATED WORK SLOWDOWN. THE SAFETY BOARD HAS ISSUED RECOMMENDATIONS ADDRESSING SIMILAR FLIGHT CALL SIGN CONFUSION.
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
- Flight time: 3,264 hours in all; 1,264 in this make and model
- Medical certificate: Class 1
- Seat: unk
The aircraft
- Last inspection: inspection type not recorded; 0 hours since
- Maximum gross weight: 12,300 lb
- Seats: 36
- Landing gear: retractable
- Engine: P&W PT6A (turboprop); 0 hours total
- Operator: Simmons Airlines
The flight
- Departed from: ORD
- Destination: SBN South Bend IN
- Flight plan: IFR
- Runway 4L, 7,500 ft by 150 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 040° at 10 knots
- Visibility: 15 statute miles
- Sky: clear
- Temperature: 21°F (-6°C), dew point 10°F (-12°C)
- Altimeter: 30.00 inHg
- Observation at 1:00 am from ORD
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 3 | |||
| Passengers | 34 |
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.