What happened
On 29 June 2004, a Piper PA-34-200 Seneca, registration G-EMER, was conducting a training flight at Old Sarum Airfield in Wiltshire. Following a successful takeoff, the pilot selected the landing gear to the up position, at which point a 'gear unsafe' warning light illuminated. Although the main landing gear successfully locked, the nose landing gear failed to indicate a down and locked status.
In an attempt to rectify the issue, the pilot followed established procedures, including the manual emergency extension of the gear. Despite applying increased positive g-loads and performing side-slips, the nose gear remained partially extended. After consulting with airfield personnel, the pilot attempted a touch-and-go maneuver on the grass runway, intending to use the impact to jolt the gear into position. However, during the maneuver, the aircraft pitched nose-down. The unlocked nose gear collapsed upon contact with the surface, causing the propellers and nose cone to strike the ground. The pilot was uninjured, but the aircraft sustained damage to the nose gear assembly, the nose cone, and both propellers.
The investigation
Investigators examined the nose landing gear assembly to determine why the gear could not be locked. The inspection revealed that a bracket within the nose landing gear bay had fractured. This failure allowed the upper section of the gear's guide track to pivot upward, creating a gap in the assembly.
As the gear began to retract during the initial takeoff, the roller assembly moved along the track until it reached this gap and jumped out of the channel. This displacement prevented the gear from reaching the fully extended position and caused the nose wheel to deflect from the aircraft's centerline. The investigation found that the location of the failed U-bracket was such that the defect was not detectable during a standard pre-flight inspection.