What happened
On March 5, 2016, a private flight departing from Zurich Airport (LSZH) for London Biggin Hill (EGKB) resulted in a runway excursion. The aircraft, an Embraer Phenom 100 with registration HB-VRV, was being operated under instrument flight rules.
During the taxi from the parking stand toward the holding point for runway 28, the pilot noticed that the aircraft was not responding to standard steering inputs. To compensate for this lack of control, the pilot utilized differential braking to maneuver the aircraft. Despite adjusting the rudder pedals multiple times, the steering behavior remained abnormal.
After completing the pre-takeoff checklists at the holding point, the aircraft entered runway 28. Shortly after applying takeoff power, the pilot experienced intense vibrations from the nose gear and decided to abort the takeoff. During the braking phase, the aircraft initially tracked along the centerline but then swung approximately 100 degrees to the right. The nose gear eventually left the paved surface, and the aircraft came to a stop in the adjacent grass field. The incident resulted in one light injury to a passenger, while the crew and the aircraft remained uninjured.
The investigation
The investigation focused on why the nose wheel steering was non-functional during the taxi and takeoff roll. The pilot had performed an external pre-flight inspection, which he noted was often done from memory rather than using a written checklist.
Investigators examined the nose gear assembly and discovered that the torque link pin was not engaged, leaving the torque link disconnected from the nose wheel steering mechanism. This disconnection allowed the nose wheel to rotate freely, preventing the pilot from directing the aircraft through the rudder pedals.
Findings
- The primary cause of the loss of control during the aborted takeoff was the disconnection of the nose wheel steering due to the torque link pin being in the wrong position.
- The pilot failed to notice that the torque link was uncoupled during the pre-flight inspection.
- The pilot attempted to manage the steering deficiency using differential braking, a technique known to him from previous training on other aircraft types.