Death of Ayrton Senna - Trial

Trial

The Williams team was entangled for many years in a court case with Italian prosecutors over manslaughter charges, ending in a guilty verdict for Patrick Head. The Italian Court of Appeal, on April 13, 2007, stated the following in the verdict numbered 15050: "It has been determined that the accident was caused by a steering column failure. This failure was caused by badly designed and badly executed modifications. The responsibility of this falls on Patrick Head, culpable of omitted control". The initial trial in 1997 resulted in acquittals after the judge ruled that the prosecution had failed to prove its case, but a retrial was ordered by Italy's highest court. Patrick Head was not arrested as the sentence was backdated to the time of the crash, 1 May 1994. The limitation under Italian law for culpable homicide was 7 years and 6 months, and the verdict was pronounced 13 years after the accident.

The charges focused on the car's steering column, which was found to have sheared off at a point where a modification had been made. The prosecution charged that the column had failed causing the accident, and Williams contended that it had failed on impact. Senna did not like the position of the steering wheel relative to his seating position and had asked for it to be changed. Patrick Head and Adrian Newey agreed to Senna's request to lengthen the FW16's steering column, but there was no time to manufacture a longer steering shaft. The existing shaft was instead cut, extended with a smaller-diameter piece of tubing and welded together with reinforcing plates.

A 600-page technical report was submitted by Bologna University under Professor of Engineering Enrico Lorenzini and his team of specialists. The report concluded that fatigue cracks had developed through most of the steering column at the point where it had broken. Lorenzini stated: "It had been badly welded together about a third of the way down and couldn't stand the strain of the race. We discovered scratches on the crack in the steering rod. It seemed like the job had been done in a hurry but I can't say how long before the race. Someone had tried to smooth over the join following the welding. I have never seen anything like it. I believe the rod was faulty and probably cracked even during the warm-up. Moments before the crash only a tiny piece was left connected and therefore the car didn't respond in the bend."

An analysis of the onboard camera video was submitted by Cineca, which tracked the movement of the steering wheel during the race. Having rotated in a fixed arc during the previous laps, during the final seconds a yellow button on the wheel moved several centimetres away from its normal trajectory, with the steering wheel tilting in its own plane, indicating a breaking steering column. Williams introduced its own video to prove the movement was normal in which David Coulthard manhandled an FW16B steering wheel, the effort required to deflect the wheel termed as "quite considerable". Coulthard's testimony stood in contradiction to that of Michele Alboreto, who testified that the steering wheel movement was abnormal.

During the trials, a regional technical commissioner named Fabrizio Nosco testified that both of the vehicle's black boxes were intact, except for minor scratches. He said "I have seen thousands of these devices and removed them for checks. The two boxes were intact, even though they had some scratches. The Williams device looked to have survived the crash." In a move that apparently breached FIA regulations, Charlie Whiting, an FIA official, handed the black boxes to Williams before the regulating body's own investigation into the accident. Williams claimed the black boxes were unreadable, and the boxes returned for the court proceedings were indeed unreadable, a full month after the accident.

On 17 December 1997, Frank Williams and the five others were acquitted of the charges which ended a boycott of Formula One in Italy which would have been supported by Benetton Formula. Judge Constano ignored a request from the proscution to give one-year suspended sentences to Patrick Head and Adrian Newey.

At the conclusion of the Italian trial, Senna's FW16, chassis number 02, was returned to the Williams team. The team reported that the car was in an advanced state of deterioration and was subsequently destroyed. The car's engine was returned to Renault, and its fate is unknown.

In January 2003, the Italian Supreme Court reopened the case, referring it to the Bologna Court of Appeal. The decision to reopen the case was made in April 2004 ruiling that “material errors” had been made. The trial was asked to be halted in May 2005 by proscutor Rinaldo Rosini believing the case was unable to proceed further because of a statute of limitations on the charges brought forward.

In May 2011, Williams FW16 designer Adrian Newey expressed his views on the accident: "The honest truth is that no one will ever know exactly what happened. There's no doubt the steering column failed and the big question was whether it failed in the accident or did it cause the accident? It had fatigue cracks and would have failed at some point. There is no question that its design was very poor. However, all the evidence suggests the car did not go off the track as a result of steering column failure... If you look at the camera shots, especially from Michael Schumacher's following car, the car didn't understeer off the track. It oversteered which is not consistent with a steering column failure. The rear of the car stepped out and all the data suggests that happened. Ayrton then corrected that by going to 50% throttle which would be consistent with trying to reduce the rear stepping out and then, half-a-second later, he went hard on the brakes. The question then is why did the rear step out? The car bottomed much harder on that second lap which again appears to be unusual because the tyre pressure should have come up by then – which leaves you expecting that the right rear tyre probably picked up a puncture from debris on the track. If I was pushed into picking out a single most likely cause that would be it."