Boeing 757-223 incident near Chicago, Illinois, September 22, 2008
On September 22, 2008 at about 6:42 pm local time, a Boeing 757-223, registered N197AN, suffered minor damage in an incident during enroute near Chicago, Illinois (O'Hare International Airport). It was flown under scheduled airline rules (Part 121). No one was hurt; 192 people were on board or involved.
The NTSB's probable cause their words, unchanged
The failure of an electrical relay due to eroded contacts and the flight crew's decision to continue a flight that was operating on battery power.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 22, 2008 · about 6:42 pm local time
- Place
- Chicago, Illinois · O'Hare International Airport · map
- Type
- Incident
- Injuries
- No one was hurt; 192 people were on board or involved.
- Weather
- not recorded
- Aircraft
- Boeing 757-223 · all 757-223s on the register
- Registration
- N197AN · no longer on the register · serial NT975
- Damage
- Minor damage
- Flight
- Flight · scheduled airline rules (Part 121)
The NTSB's narrative final · quoted from the NTSB record
While performing the cockpit preflight, the captain noticed that the standby horizon was unpowered. After cycling the Standby Power Selector and the Battery Switch, the captain noted that five status messages were displayed on the engine indicating and crew alert system (EICAS) screen, although he could not remember the specific messages. Maintenance personnel subsequently cleared the messages and told the crew they were "good to go," without making a logbook entry. Approximately 30 minutes after takeoff several cockpit lights flickered; multiple EICAS messages appeared, including the AIR/GRD SYS caution message; the Standby Power OFF light illuminated; the autopilot disconnect warning sounded; and the autothrottles disconnected. The first officer referenced the STANDBY BUS OFF procedure in the QRH, turning the Standby Power selector to the BAT position. The QRH states that when BAT is selected the battery will provide bus power for approximately 30 minutes. Although the QRH did not instruct the crew to divert to the nearest suitable airport, it indicates that the battery will supply bus power for approximately 30 minutes and the captain reported to maintenance that the battery would be depleted. After consulting with company maintenance specialists, the crew elected to continue the flight. Battery power was depleted and numerous essential aircraft systems began to fail about 2 hours and 24 minutes after the flight crew switched the Standby Power selector to the BAT position. These systems included the stabilizer trim, the captain’s instrumentation, thrust reversers, anti-skid and others. The flight diverted to the closest airport, an emergency was declared, and the airplane was cleared to land on the 7,500-foot-long runway; the captain stated that due to problems controlling the airplane, he did not want to circle to land on a longer runway. The airplane touched down hard about 2,500 feet down the runway. The crew determined they were going to overrun the end of the runway, so the captain veered the airplane off the left side of the runway into the grass, where the airplane came to rest with seven of the eight main gear tires either blown out or deflated. Postaccident investigation revealed erosion on the B contacts within the K106 relay; a failure of the K106 electrical relay would result in the events described by the crew.
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
What happened, in order
- Electrical system malf/failure during enroute defining event
- Off-field or emergency landing during landing (landing roll)
- Collision with terrain or object (not controlled flight into terrain) during landing (landing roll)
The NTSB's findings
- cause Aircraft › Aircraft systems › Electrical power system › DC power distribution system › Fatigue/wear/corrosion
- Organizational issues › Development › Manufacture/production › Document/info production › Manufacturer
- Organizational issues › Management › Policy/procedure › Adequacy of policy/proc › Operator
- cause Personnel issues › Action/decision › Info processing/decision › Decision making/judgment › Flight crew
- Personnel issues › Action/decision › Info processing/decision › Understanding/comprehension › Flight crew
Pilot
- Certificate: airline transport pilot, flight instructor, flight engineer
- Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instrument: airplane
- Flight time: 11,285 hours in all; 580 in this make and model; 139 in the last 90 days; 39 in the last 30 days; 7,568 as pilot in command
- Last flight review: March 13, 2008
- Medical certificate: Class 1 (with waivers/limitations)
- Seat: left
- Injury: no injuries
Co-pilot
- Certificate: airline transport pilot
- Ratings: multi-engine land; instrument: airplane
- Flight time: 11,700 hours in all; 1,635 in this make and model; 88 in the last 90 days; 19 in the last 30 days; 4,300 as pilot in command
- Last flight review: September 3, 2008
- Medical certificate: Class 1 (with waivers/limitations)
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 22,094 hours
- Last inspection: continuous airworthiness programme, September 21, 2008; 3 hours since
- Maximum gross weight: 251,000 lb
- Seats: 197
- Landing gear: retractable
- Engine: Rolls Royce RB.211-53 (turbofan); 0 hours total
- Operator: American Airlines, Inc.
The flight
- Departed from: SEA Seattle WA at 3:01 pm
- Destination: JFK New York NY
- Flight plan: IFR
- Runway 22R, 7,500 ft by 150 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: at 6 knots
- Visibility: 10 statute miles
- Sky: broken clouds at 25,000 ft; a few clouds at 5,000 ft
- Temperature: 81°F (27°C), dew point 61°F (16°C)
- Altimeter: 30.31 inHg
- Observation at 6:51 pm from ORD
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Cabi | 5 | |||
| Flight crew | 2 | |||
| Passengers | 185 |
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.