The inquiry set-up by Honda to establish the cause of Daijiro Kato's death at the season opening Japanese Grand Prix has declared that mechanical failure was not to blame – and that the former 250cc world champion's fatal accident was probably triggered by a loss of rear grip.
The six-month investigation - chaired by Professor Ichiro Kageyama of Nihon University's College of Industrial Technology - believes Kato was pushing hard to catch the race leaders and that his rear tyre began to slide when he braked hard for the chicane, at a speed of 170km/h.
"According to the on-board data, we conclude that the engagement of the front brake abruptly changed the load on the rear wheel, which lifted almost entirely off the ground, causing a lateral skid," declared the Daijiro Kato Accident Investigation Committee report. "From data on the change in suspension and acceleration sensors that followed, we can confirm that the vehicle entered a high-side like condition."
While the Japanese was able to partially control the slide - by reducing his braking - the bike began to kick ever more violently, shaking from side-to-side (oscillating). This instability also caused a loss of balance and Kato was thrown over to the left side of the bike, taking his right foot off the footpeg - and removing any chance of using the rear brake - in the process.
These factors combined are believed to have resulted in the #74 veering sharply left into the trackside tyre wall, on lap 3 of the April 6 event.
After the initial contact, Kato travelled along the tyre wall, still on his bike, before eventually hitting a new section of foam protection which - together with the closeness of the barrier - contributed significantly to the extent of his injuries.
