Saab-Scania SF340A, G-RUNG
The aircraft landed at Guernsey on Runway 27 following a flight from Jersey. After landing the commander attempted to turn off the runway at taxiway ‘Charlie’ but discovered that there was insufficient steering authority to complete the turn. The right main landing gear went onto the grass surface alongside the taxiway and sunk in as the aircraft came to a halt. There was no damage to the aircraft and the passengers were disembarked onto the taxiway. The weather conditions were clear, the surface wind was from 320º at 15 kt and the runway surface was wet. The landing distance available on Runway 27 was 1,453 metres (4,767 feet), with the entrance to taxiway ‘Charlie’, a 90º turn, located at 1,070 metres (3,510 feet) on the left hand side. Following the incident the aircraft was inspected by the contracted maintenance organisation. No fault was found with any of the aircraft systems. The commander attributed the loss of steering, as the aircraft left the runway, to his continuous use of brakes through the landing roll producing a reduced pressure in the hydraulic system, leading to a temporary loss of pressure to the nosewheel steering when he tried to use it. Then as the pressure recovered the nosewheel steering became effective, but too late for him to be able to maintain the taxiway. The nosewheel steering is operated by a single hydraulic actuator and is controlled by a wheel mounted on the left seat pilot’s side panel and spring loaded in the up position. To steer, the wheel must be pushed down to engage mechanically with the steering system and to complete the electrical circuit to open the steering shutoff valve. If the steering wheel is released it will extend into the disengaged position. When the nosewheel is deflected more than approximately 15º without the steering wheel being pushed down, it will lock in its present position and limit further deflection of the nosewheel.
Saab-Scania SF340A, G-RUNG 9-05.pdf (160.84 kb)