Nosetto, director of Santerno (the company which took care of the track) from '80 to '89, said that there are two rules, that of Csai of '62 and the international one, which had changed in time. The rules had been followed for the wall against which Senna crashed: the wall was made of deformable concrete, built to absorb shocks and was built at an angle of no more that 30 degrees, as for regulations (Senna's impact was at 22 degrees). After 1989, when Nosetto left, behind the grassy area a concrete zone 9-13 metres wide was built to allow emergency manouvres.
The magistrate said that on leaving the track the front wheels of Senna's car lifted off, in fact it is possible to see the tyre marks where the wheels left the ground and where they fell back off on it. The passage from the grass to the concrete area, with braking distance of 38.5 metres, took place in 0"6. On the track deceleration was of 4G, on the grass/cement of 0.8G.
Del Monte said that the car lost grip. The average slope of the track at the time was +3.1%, that of the escape area +2.1%. At the Tamburello there only was a grass/concrete area and not a full escape route, as it is required by the rules, because of lack of space.
The escape area should have had the same slope as the track. There can be slight variations, as long as the ideal line track-escape area is constant, without bumps and with a maximum radius of 50 metres.
The defense produced a CD, based on the telemetry data, containing a large number of diagrams, which Giavotto used to reconstruct the real and optimal braking times. According to this interpretation, Senna hit the wall at 188 km/h versus the 216 km/h calculated by the prosecution experts. In ideal conditions he would have crashed at 167 km/h (the prosecution experts had calculated 140 km/h). In both cases the front right wheel would have become detached, hitting Senna's head in the same point with enough violence to kill him.
Next hearing will take place on 16th of September, after the summer break.
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