Simmons ATR ATR 42 incident
ATR ATR 42 · Incident during initial climb
From Chicago O'Hare International Airport (ORD) to Chicago O'Hare International Airport (ORD)
Event
- NTSB case
- CHI93IA126
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Incident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Airline
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Instrument Meteorological Cond
ATR ATR 42
- Aircraft type
- ATR 42
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N426MQ
- Operator
- Simmons
- Onboard fatalities
- Unknown
- Route
- From Chicago O'Hare International Airport (ORD)To Chicago O'Hare International Airport (ORD), IL
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 121: Air Carrier
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Initial climb
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Miscellaneous/other
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- None
Cause areas
- Atc personnel(lcl/gnd/clnc) › Atc clearance, improper
- Atc personnel(lcl/gnd/clnc) › IFR separation standards, not maintained
Approximate · Estimated position: the centre of Chicago, IL, the place the record names. Not the accident site.
NTSB narrative
RUNWAY CONFIGURATION WAS IN THE PROCESS OF BEING CHANGED FROM ARRIVALS & DEPARTURES ON RUNWAYS 32L & 32R TO DEPARTURES FROM 32R & ARRIVALS TO 32L. SIMMONS 4321, AN ATR-42, WAS CLEARED FOR TAKEOFF BY THE NORTH LOCAL CONTROLLER (NLC) FROM RUNWAY 32R & SUBSEQUENTLY WAS INSTRUCTED TO TURN LEFT HEADING 270 DEG. THE SOUTH LOCAL CONTROLLER (SLC) THEN CLEARED UNITED 1206, A DC-10, FOR TAKEOFF FROM RUNWAY 32L. WHEN UNITED FLIGHT 1206 BECAME AIRBORNE, SIMMONS 4321 HAD ALREADY STARTED THE LEFT TURN WHICH PUT THE AIRCRAFT IN THE DEPARTURE PATH OF FLIGHT 1206. SEPARATION WAS REDUCED TO ZERO FEET VERTICALLY & .5 MILE LATERALLY. THE NLC SAID HE HAD A DISCUSSION WITH THE AREA SUPERVISOR REGARDING DEPARTURE HEADINGS (IF THERE WERE NO DEPARTURES ON RUNWAY 32L); IN THE CONVERSATION, HE THOUGHT THE AREA CONTROLLER HAD INDICATED THAT A LEFT TURN WOULD BY ALRIGHT. HOWEVER, THE AREA SUPERVISOR DENIED DISCUSSING A LEFT TURN; HIS RECOLLECTION WAS DISCUSSING THE USE OF A 340 DEGREE HEADING VERSUS A 350 DEGREE HEADING TO PROTECT FOR MISSED APPROACHES.
Probable cause
AN IMPROPER CLEARANCE BY THE NORTH LOCAL CONTROLLER, WHICH RESULTED IN A FAILURE TO MAINTAIN PROPER IFR SEPARATION. A FACTOR RELATED TO THE INCIDENT WAS: INADEQUATE COORDINATION AMONG THE TOWER PERSONNEL.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI93IA126
- Event ID
- 20001211X11942
- Case number
- CHI93IA126
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, damage. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: dffcf35578e3abb4e4194b5944b21876c4921ba933ca225bac8777d1c78265f9; retrieved 2026-09-18T18:40:20.519Z.