What happened
On 26 February 2011, a Dynamic WT9 UK, registration G-DYNM, was performing a training flight at Chiltern Park Aerodrome in Oxfordshire. Following an uneventful flight, the pilot landed the aircraft on the aerodrome's grass strip.
As the aircraft proceeded along the landing roll at an estimated speed of 15 kt, the pilot applied the brakes. During this process, the aircraft's nose pitched up and down twice in rapid succession. The sequence of events concluded when the nosegear collapsed, causing the aircraft to come to rest on its engine cowling. The incident resulted in damage to the engine cowling, the nose leg, and the nosewheel.
The investigation
Investigators examined ground marks left by the aircraft to reconstruct the sequence of the landing roll. The tracks consisted of a short depression, approximately 1 metre long and the width of the nosewheel, followed 21 metres later by two marks left by the propeller striking the ground. A further deep gouge was identified adjacent to the location where the nosewheel had detached.
While the pilot noted that the airfield generally has good drainage and had not experienced recent rainfall, the physical evidence indicated a significant disturbance in the surface. The pilot suggested that the initial depression might have been caused by the nosewheel sinking into soft ground, which then caused the aircraft to pitch upward as the wheel hit firmer ground. It was also noted that the impact might have caused the nosegear to detach, though the possibility of pre-existing damage could not be excluded.
Findings
- The aircraft experienced a series of pitch oscillations during the braking phase of the landing roll.
- The landing roll resulted in the nosewheel sinking into soft ground, leading to the detachment of the nosegear and subsequent propeller strikes.