Aircraft

A nose-wheel steering failure has emerged as the likely culprit in an recent incident involving an American Eagle ERJ-145LR that hit three runway lights and a runway sign during a late night roll-out at Madison Wisconsin's Dane County airport.

The aircraft, with 29 passengers and three crew on board, was inbound from Dallas/Fort Worth. No-one was injured in the incident, which burst one of the ERJ's two nose gear tyres and damaged the Liebherr-built nose wheel landing gear assembly.

The airline says that the pilots received a "hydraulic message" on the flightdeck before landing, but that the message "went away" after the landing gear was lowered. "When he touched down, he couldn't steer it very well," says the airline, adding that the pilots were able to keep the aircraft "on the runway" after the collision with the lights and sign.

American says it has had similar incidents, but not on that particular aircraft.

Last month, an American Eagle ERJ-135 partially touched down with its wheels stowed at Boston Logan International airport due to problems with its landing-gear electronics unit. Pilots later manually lowered the landing gear and landed without incident. The US National Transportation Safety Board continues to investigate.

US Federal Aviation Administration service difficulty reports list at least a dozen problems related to the Parker Hannifin-built nose-wheel steering system on ERJ-145 series aircraft, dating to 2001.

The NTSB investigated an incident in June 2004 when a Chautauqua Airlines ERJ-135LR lost nose-wheel steering in Dallas/Fort Worth, causing minor damage and one case of whiplash to a passenger. Investigators later determined that contamination in the hydraulic steering system was the likely culprit.

Two months before that incident, Embraer had issued a service bulletin listing procedures that pilots should follow in the event of "uncommanded swerving" during high-speed taxi, take-off and landing phases of a flight.

The actions called for pilots to control the aircraft using rudder commands and differential braking, but recommended disconnecting the nose-wheel steering and controlling with differential reverse thrust if problems continued.