The crew were taxiing at Birmingham International. The commander turned the tiller to the right but the aircraft did not turn. He applied right rudder and right brake and brought the aircraft to a halt, with the MLG on the grass. At this point the ‘nose steering’ fault light was illuminated and the FO’s ASI had failed. The wind was from the left at 11 kt. The passengers were disembarked onto a bus. On 6/1/05 there was another ASI problem on the ground on G-JEDI. Investigation a problem with the wiring harness from the WOW2 sensor and this was repaired. The FDR showed WOW signal was intermittent during the taxi at Birmingham. The loss of signal from WOW1 or WOW2 gives an FDR loss of WOW signal and SCU removes steering commands from the actuators. The loss of steering from tiller and rudder inputs was consistent with the loss of one WOW signal from the NLG while the crew were attempting to steer the aircraft on the ground at low speed.
Published 10 December 2014