What happened
On 1 March 2010, a Skyranger Swift 912S, registration G-CEZE, was performing a local private flight in favorable weather conditions. While returning to Northrepps Airfield in Norfolk, the aircraft approached Runway 22. The landing was initially uneventful, with the aircraft touching down on the grass runway following a standard approach.
However, following touchdown, the aircraft began to drift leftward from the runway centerline. Despite the pilot's efforts to maintain control, the aircraft continued to veer toward the left edge of the runway. The aircraft subsequently exited the runway and entered a soft, muddy ploughed field at a low speed. Upon entering the field, the nosewheel dug into the ground, causing the aircraft to tip over and come to rest in an inverted position. Both the pilot and the passenger, who were wearing full safety harnesses, escaped the incident without injury.
The investigation
Investigators examined the aircraft and the site of the accident to determine the cause of the runway excursion. A post-accident inspection of the landing gear revealed that the left mainwheel tyre had become deflated at some point before the aircraft touched down. This deflation had caused a single gouge to be created in the grass runway by the left wheel. The investigation established that the loss of tyre pressure was the primary factor leading to the loss of directional control.