Airbus Industrie A320-232 incident near Chicago, Illinois, October 10, 2007
On October 10, 2007 at about 1:30 am local time, a Airbus Industrie A320-232, registered N431UA, suffered minor damage in an incident near Chicago, Illinois (Chicago O'Hare Intl airport). It was flown under scheduled airline rules (Part 121). 2 people had minor injuries; 125 others were unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The misrouted and reversed antiskid wiring by vendor maintenance personnel leading to the runway excursion. Contributing to the incident were the runway sign, the vendor's maintenance personnel not understanding the entire maintenance procedures in the dual tachometer replacement, and the operator's maintenance procedures being unclear to the maintenance personnel.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 10, 2007 · about 1:30 am local time
- Place
- Chicago, Illinois · Chicago O'Hare Intl · map
- Type
- Incident
- Injuries
- 2 people had minor injuries; 125 others were unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Airbus Industrie A320-232 · all A320-232s on the register
- Registration
- N431UA · registry record · serial 571
- Damage
- Minor damage
- Flight
- Flight · scheduled airline rules (Part 121)
The NTSB's narrative final · quoted from the NTSB record
The airplane's left main landing gear inboard and outboard anti skid tachometers wiring were reversed during scheduled maintenance at a vendor. During landing, the inboard left main landing gear's wheels went to a high braking level and the outboard wheel did not apply braking. The airplane sustained minor damage when it exited the runway and impacted runway lighting. Post incident examination of the airplane and brake components revealed no further anomalies. The vendor that performed the scheduled maintenance indicated that their personnel did not understand that the built in test equipment test they performed did not check for cross-wired tachometers. A different specified test called out in the airplane maintenance manual and in an operator's reference document indicated this specified check would verify a cross-wired condition. The operator reported that the reference documentation associated with the scheduled maintenance involving both of the left main landing gear's tachometers was unclear and that the procedure for that maintenance was revised.
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, commercial pilot, flight engineer
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 14,250 hours in all; 2,450 in this make and model; 196 in the last 90 days; 75 in the last 30 days; 6,450 as pilot in command; 1,100 on instruments
- Last flight review: June 1, 2007
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: left
- Injury: no injuries
Co-pilot
- Certificate: airline transport pilot, flight instructor, commercial pilot, flight engineer
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 10,206 hours in all; 268 in this make and model; 141 in the last 90 days; 50 in the last 30 days; 6,351 as pilot in command; 2,622 on instruments
- Last flight review: July 1, 2007
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 41,163 hours
- Last inspection: continuous airworthiness programme, October 1, 2007
- Maximum gross weight: 169,750 lb
- Seats: 146
- Landing gear: retractable
- Engine 1: Iae 2527 (turbofan); 0 hours total
- Engine 2: Iae 2527 (turbofan); 0 hours total
- Operator: United Air Lines INC
The flight
- Departed from: SEA Seattle WA at 9:49 pm
- Destination: Chicago IL
- Flight plan: IFR
- Runway 22R, 7,500 ft by 150 ft
- A second pilot was aboard
Weather at the time
- Light: night
- Wind: from 300° at 17 knots, gusting 23
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 61°F (16°C), dew point 39°F (4°C)
- Altimeter: 29.90 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | 4 | ||
| Passengers | 1 | 121 |
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.