Embraer EMB145 incident near Moline, Illinois, August 29, 2011
On August 29, 2011 at about 5:36 pm local time, a 2003 Embraer EMB145, registered N27152, suffered minor damage in an incident during landing (landing roll) near Moline, Illinois (Quad City Intl airport). It was flown under scheduled airline rules (Part 121). No one was hurt; 53 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The uncommanded left deflection of the airplane's nose wheel likely due to seal deterioration and subsequent contamination within the Electrohydraulic Servo Valve (EHSV). Contributing to the incident was the undersized condition of the filter plugs within the EHSV which likely caused the C2 orifice filter seal to extrude and deteriorate.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 29, 2011 · about 5:36 pm local time
- Place
- Moline, Illinois · Quad City Intl · map
- Type
- Incident
- Injuries
- No one was hurt; 53 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Embraer EMB145 XR, built 2003 · all EMB145s on the register
- Registration
- N27152 · registry record · serial 145759
- Damage
- Minor damage
- Flight
- Flight · scheduled airline rules (Part 121)
The NTSB's narrative final · quoted from the NTSB record
Shortly after the nose wheel touched down during the landing, the airplane turned hard left and departed the runway. Review of the Flight Data Recorder data revealed that the crew attempted to counter the initial left turn using rudder and differential breaking, and that their inputs were not the cause of the left turn. The nose wheel steering, brakes, spoilers, thrust reversers, and rudder were inspected at the aircraft level with no anomalies found. In addition, many components from the nose wheel steering system were removed and tested at the component level. Two of these components, the Steering Manifold Assembly and the EHSV, were found to have defects that could potentially affect nose wheel steering operation. The Steering Manifold Assembly failed flow tests related to bypass valve operation and a piece of plastic was discovered on the C2 filter screen of the bypass valve. The bypass valve operates when the nose wheel steering is disengaged. It connects the two steering actuating cylinder hydraulic chambers which allows the nose wheel to free caster. The observed low flow condition caused by the plastic debris could result in the reduced effectiveness of the bypass function when the nose wheel steering is disengaged. In addition, the plastic debris was in a location where it could have potentially reduced or blocked fluid flow through the C2 hydraulic port during normal nose wheel steering operation. This could have resulted in the inability or reduced capability of the nose wheel to turn in the commanded direction. Any blockage caused by this plastic debris would result in reduced performance only and could not have initiated or caused the nose wheel to turn uncommanded. The EHSV passed the manufacturer's acceptance test; however, disassembly revealed that the C1 orifice filter seal was damaged and the C2 orifice filter seal was missing material. The missing material was not located, but the void that remained on the seal from the missing fragment was larger than the C2 nozzle orifice. Depending on how the missing material separated from the C2 orifice filter seal, the size of the material was potentially large enough to block the C2 nozzle. A blocked C2 nozzle would allow hydraulic fluid pressure to build within the C2 fluid chamber, causing the control spool to move in a direction that would command a left nose wheel turn. The undersized condition of the C1 and C2 filter plug outer diameters likely contributed to the premature deterioration of the C1 and C2 orifice filter seals. The plug diameters were required to be checked when the EHSV was subjected to Service Bulletin (SB) 145-32-0099; however, the out of tolerance condition remained.
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
- Loss of control on ground during landing (landing roll) defining event
- Runway excursion during landing (landing roll)
The NTSB's findings
- cause Aircraft › Aircraft systems › Landing gear system › Landing gear steering system › Malfunction
The aircraft
- Airframe total time: 22,705 hours
- Landing gear: retractable
- Engine 1: Rolls Royce AE 3007 (turbofan); 22,535 hours total
- Engine 2: Rolls Royce AE 3007 (turbofan); 20,543 hours total
- Operator: Expressjet Airlines INC
The flight
- Departed from: DEN Denver CO
- Destination: MLI Moline IL
- Runway 10, 10,002 ft by 150 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Sky: not recorded; clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Cabi | 1 | |||
| Flight crew | 2 | |||
| Passengers | 50 |
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.