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The Death of Ayrton Senna DaSilva.

It is just over 3 years ago that Formula 1’s Ayrton Senna died after crashing out,
while competing (and in fact leading) the 1994 San Marino grand prix at Imola,
while driving an FW 14 Williams, leaving behind a sport and a worldwide fan club
that has not yet fully recovered from the loss. Due to the fact that a number of
apparently unresolved issues remain, particularly in the minds the authorities in
Italy, on who’s soil Senna died, this entire matter is still very much a current

The Italian prosecutor has in fact decided, on the basis of there being no obvious
reason why Senna’s car crashed, that Frank Williams, the team owner, the car’s
designer, Adrian Newey, Patrik Head, technical director of the team at the time
and the track owners should stand trial for manslaughter.
The prosecutor, who it must be said is acting correctly according to Italian law,
had prosecuted the team members on the basis that there was no obvious
reason why an experienced driver of Senna’s calibre should lose control of his
car and crash.
He also held that the Williams team members had allowed Senna to drive his
race car with known defects and also held that the race track officials should also
stand accused, on the basis of the poor condition of the race track surface. In
relation to the car, a broken steering column found post accident, which the
prosecution allege was negligently modified and welded immediately pre race,
was in their view responsible for the accident and Senna’s death.
It is inconceivable that intention formed any part of the mental frame of mind of
any of the defendants, hence the fact that this is not a murder trial but if
negligence or recklessness is established, this would be sufficient to successfully
convict any or all of the defendants of manslaughter.
This high profile case is of special interest to the writer for a number of reasons
but particularly because of its F1 back drop and also due to the technical
explanations being put forwarded as to the cause of the accident, by all sides in
the matter.
The Italian magistrate, Maurizio Passarini, who is in charge of the official
investigation, has assembled an undisputed team of experts headed by
Professor Lorenzini, a materials specialist at Bologna University to conduct a
technical investigation into the circumstances of the accident and based on their
findings, the prosecution have brought manslaughter charges against all of the
defendants in the case.
The investigation team, using highly technical 3D computer generated
simulations, coupled with telemetry data from the two on board black boxes and
video images from the on board T.V. camera, have what they believe is an
accurate reconstruction of the accident circumstances, which is forming the basis
of the prosecution case.
It is worth pointing out that the black boxes mentioned above are not the same in
design or function to the black boxes used in aircraft, which assist air accident
investigators reconstruct air accidents. F1 black boxes, as in this case, provide a
means for Williams to monitor chassis and gearbox parameters, and Renault to
monitor engine performance data during each race by means of a radio link to
the pits, for instantaneous and subsequent evaluation.
Although both black boxes also have some data recording capability, their
primary purpose is not accident investigation and although I accept that the data
produced has some investigational value, this data proves nothing in relation to
the alleged broken steering component. In fact, this data shows that Senna,
while negotiating the now infamous Tamburello bend, throttled off in two stages
immediately prior to his car leaving the racing surface, which suggests that at
least as far as Senna was concerned, there was nothing wrong with his steering
at that point, late in the sequence of events.
It further indicates that he was trying to correct the car’s trajectory with the
steering, rather than brake, prior to impacting the wall on the outside of the bend.
Although the central argument is simple, the technical argument has become
extremely complex with the prosecution maintaining that the steering column
fractured prior to the accident, thus causing the accident and the defence
maintaining that the severity of the impact caused the steering column fracture,
because of the high forces involved in the crash.
It’s the classic “cause and effect” argument which in my view is not capable of
being fully resolved and depending on which side of the “fence” the argument is
being put forward from, both sides of the argument can be argued with equal
enthusiasm and vigour.
Of crucial importance in evaluating this matter are the statements of Michael
Schumacher (who was in second place behind Senna and who was following
close behind) indicated that Senna’s car was producing an abnormal amount of
sparks because it appeared to be riding much closer to the ground, than usual.
In order to appreciate why this was the case, it is necessary to understand the
factors which affect the ride height of a F1 car.
The FW 16 Williams in particular had a particularly rigid suspension to the point
that it was not a suspension at all in in the normal context. It is desirable, within
the race set up of a F1 car, to run the vehicle as close to the ground as possible,
particularly at Imola which is known to be a fast circuit. The advantage of the
undershell aerodynamics can only be utilised provided the vehicle runs as close
to the ground as is feasible without touching, with the only flexibility in the ride
height being provided by the side walls of the tyres.
In other words, lower tyre pressures, lower ride height, softer setting, higher tyre
pressures, higher ride height and a harder “suspension” setting. At the optimum
setting, the FW 16 would have been an extremely difficult and uncomfortable car
to drive on anything other than a smooth surface. As race tyres warm up, the
temperature of the tyres causes the air within the tyres to expand, thus
increasing the pressure within the tyres, and thus increasing the ride height of the
car, therefore affecting its handling.
It is necessary for the engineers to calculate in advance of each race, the
expected temperature of the day of the race and adjust the tyre pressures
accordingly. The purpose of the heated tyre blankets is to bring the tyres as
close to race temperature as possible so that the optimum tyre pressure (and
therefore ride height) is reached as soon into the race as possible. The effect of
this is that the car does not reach its optimum racing setup until the tyres have
fully warmed up.
The car starts the race lower and rises up as the temperature of the tyres
Admittedly, the height variation is very minor but vitally important given that the
height difference may only result in the difference of a fraction of a second per
lap, but in a 55 lap race (on average) the winning margin may only be 10 to 15
seconds or so and sometimes less. The cumulative effect of a very minor lap
advantage therefore, has huge significance as the race progresses.
On the day in question prior to Senna’s accident, an incident on the track
required the safety car to appear for a total of six laps, during which time
the tyres, despite the drivers attempts to keep them fully warm by weaving
back and forth across the track, would have cooled down, and particularly
in the case of the Williams car, would have reduced the ride height. I
believe that this is a crucial factor in the accident occurring.
Ayrton Senna died of severe head injuries after being struck by a long smooth
object with a rounded end above the right eyebrow, believed to have been
inflicted by a section of suspension arm which became airborne after the impact.
Theoretically, race helmet visors are thought to be practically bullet proof and are
tested to withstand stone impacts travelling many hundreds of miles an hour. In
this case however, it is thought that the suspension component (although the
precise section of component was not positively identified) somehow penetrated
the helmet through the small gap between the helmet and the top of the visor.
Were it not for this unlucky fatal blow, Senna would in all probability have
survived this accident, notwithstanding the fact that his car struck a concrete wall
at the outside of Tamburello, at a speed in excess of 100 mph.
While the prosecution seems to be utterly preoccupied with the theory of the
negligently (or recklessly) modified steering column and as a consequence, who
killed Senna, they appear to be totally ignoring other vitally relevant factors and
not asking the most important and constructive question of all, what killed Ayrton
It is not surprising that the prosecution seems to be totally obsessed about
pursuing the “who” question, given the amount of money that they have spent
attempting to prove the defective steering scenario, by means of exotic computer
generated reconstructions and other means.
Central to this evidence are the “in car” video camera clips which shows among
other things, sunlight reflecting on the left front steering arm of Senna’s car in
addition to showing Senna’s “body language” as he negotiates the various bends
leading up to the accident scene.
Taking the second issue first, it will be appreciated by most everyday drivers that
during the course of negotiating a significant bend, particularly one that’s taken
slightly to fast, there is a tendency to lean one’s body, and particularly one’s head
towards the inside of the bend almost in an effort to encourage the vehicle
around the bend.
Countering centrifugal and centripetal forces is actually the reason why this
occurs and racing drivers, because of the substantially higher forces involved
and depending on individual driving style, tend to exaggerate this.
Consider a race car turning a corner at speed, centripetal forces are
applied to the vehicle from the frictional effects between the track surface
and the tyres. Centrifugal forces are applied by the car, opposing the
centripetal force. If the track and tyre conditions cannot create enough
centripetal force from friction, then there is not enough “pull” to keep the
car on it’s circular path and it will skid, usually at a tangent to the circular
Simply put, when a bucket is filled with water, it can be rotated vertically by
the handle and if the swing is fast enough, the water will remain in the
bucket even while it is inverted. The centrepetal force is being provided by
the person’s arm, preventing the bucket from departing from the circular
motion and the centrifugal force keeps the water in the bucket, while it’s
The above paragraphs should be borne in mind and will be helpful when
evaluating the conclusions of this article. In relation to the reflected sunlight on
the left steering arm of Senna’s car, it is argued by witnesses for the prosecution
that the in car video footage shows that sun light flashes on the metal steering
arm move to the left (relative to the video camera) and at the same time, Senna’s
gloved hand moves towards the bottom of the steering wheel, proving it is argued
that the steering was working at this point.
Senna’s helmet can then be seen moving dramatically further to the left as if he
is trying to instinctively correct the car’s path of travel (under steering) and at the
same time, the points of light on the metal steering arm move to the right, the
inference being that the arm is moving back towards the body of the car and the
steering wheels are adopting the straight ahead position.
This proves the prosecution allege, that the steering wheel and the road wheels
are no longer connected and that steering failure occurred at this point.
Mysteriously, the “in car” picture stops at that point and the final seconds prior to
the impact with the wall and the impact itself is not captured on tape.
I have a number of difficulties with this theory, the first being that as Tamburello
is a tight left hand bend, the sun’s relative position to the car will change as the
car negotiates the bend and as a consequence, the points of reflected light on
the steering arm will also move along the arm without the car’s steering wheel
being turned further in either direction.
Secondly, I would argue that Senna’s helmet dramatically moving further to the
left can be explained by Senna’s realisation that his car was seriously under
steering and the movement of his head to the left was simply an instinctive
reaction to this fact. Thirdly, and most importantly, detailed analysis of the
steering column showed that it was cracked through only 20% approx. of it’s
cross sectional area therefore it still had 80% approx. connection which was
more that sufficient to manoeuvre the vehicle.
The important point here is that although the steering column was found to be
cracked post accident, it was still connected and therefore did not fail. The
possibility that the cracking of the steering column was caused by the severity of
the impact, does not appear to be receiving any serious consideration by the
prosecution, but remarkably, they were prepared to join the track owners as co
defendants on the basis that the bumps at Tamburello and elsewhere on the
track may have caused enough vibration to damage the welding on the steering
column of the Williams.
This, it appears to me, to be tacit acceptance that the welding could have failed
as a result of the impact also. It is important to recall at this point that the
telemetry data showed that Senna throttled off in two stages rather than brake,
suggesting that at that late stage, Senna was confident of controlling the
This view is supported by the fact that the television images of the Williams,
shows no sign that emergency braking was initiated and the absence of tyre
smoke prior to the car departing the track is extremely relevant. Given the extent
that the prosecution say the steering column and wheel was moving around prior
to the accident suggesting free play in the mechanism, I find it inconsistent that a
driver of Senna’s calibre would not have noticed such excessive movement,
particularly when one considers the extent to which an F1 driver is involved in the
technical pre race set up.
In the context of the cause of the accident, I would suggest that Senna’s loss of
control of the Williams was due to the underside of the car “bottoming out” on the
bumps in the vicinity of the Tamburello bend, due to it’s lower ride height, so as
to cause the level of grip between the tyres and the track surface to degrade
sufficiently, therefore reducing the centripetal force to a point that allowed
centrifugal force to take the car off the track, which would be equivalent to letting
go the swinging bucket of water, in the above example.
The effect of this would result in the Williams sliding off the track on it’s belly with
most of the weight of the car being transferred to the track through it’s underside
rather than all of the weight of the car being transferred to the track through the
Having viewed many hours of video footage of the race and particularly the
accident itself, I have concluded that the failed steering column is a utter red
hearing and I strongly feel that the manslaughter charges should be dropped.
Many people feel that this case should never have been brought and there are
those who cynically feel, justifiably or not, that had this been an Italian racing
team, the Italian authorities would not have acted in the manner they have in this
On that black weekend approx. three years ago, another driver, Roland
Ratzenberger of the Simtek team was also killed at the same track, yet the
authorities felt that as his death was not suspicious, no one was charged in that
instance. In contrast to the Italian authorities position, Flavio Briatore, team boss
of the Italian based Benetton team to his credit, suggested that if charges were
brought against Williams, his team would boycott the Italian and San Marino
GPs. If the Williams team and others are actually convicted, that decision may
well result in Italian tracks being removed from the F1 calender in the future.
If anything is to be learned from Senna’s death, which ought to be the real
purpose of any enquiry, the presence of certain concrete walls, at strategic
locations on various F1 tracks around the world should receive serious
consideration. The wall that Senna struck at Tamburello is still there and may yet
claim further victims. It has been struck many times previously without fatality
primarily due to the slightly different angle that the wall was struck on those
occasions. On this point, I can recall accomplished drivers such as Gerhard
Berger, Nelson Piquet and Ricardo Patrese all crashing at the Tamburello bend,
during previous races and this fact is difficult to ignore in relation to the well
documented bumps in this area of the track.
Numerous other theories also abound in relation to the cause of this accident, the
most interesting of which is the track debris theory which is something that I
dismiss as being irrelevant, primarily due to the fact that the newspaper photos,
showing something on the track prior to the accident, depict an area of the track
approx. 700 meters before the bend where the accident occurred and unless this
debris damaged a tyre for instance (which it did not) it’s remoteness from the
accident scene renders the likelihood of it’s involvement in the accident, slight in
the extreme.
Interestingly, none of the drivers (and presumably even Senna) saw track debris
in the vicinity of the accident scene and certainly no driver reported seeing any
debris on the track (as far as I am aware) after the race. This I find peculiar
given that six slow laps behind the safety car would have given the drivers ample
opportunity to view the track, in a manner not possible to view it during a race
and surely, any track debris would have been noticed by at least some of the
drivers at that time.
Another theory being suggested is that Senna passed out because of a particular
breathing technique he used of holding his breath, in order to intensify his
concentration for and during a race. These theorists put forward as proof of this,
the fact that Senna’s head falling dramatically to the left in the “in car” shots, is
actually Senna becoming unconscious. I have already dealt with this point
earlier. Medically, I would have thought that this theory would be impossible to
prove or disprove at any subsequent post mortem, but in any event, it should be
remembered that the telemetry data showed that throttle, brake and steering
inputs were being made by Senna, up until the last second and this is not
consistent with a driver who has passed out.
My views have been arrived at and outlined here without having examined a
single piece of physical evidence (although I have viewed the “on line”
photographs of the wrecked car and various other components removed from it
after the accident). This article is therefore simply, a critical evaluation of the
technical evidence that has been presented at the trial so far, my own knowledge
of F1 and what I witnessed myself via the television images on race day (and
what I have viewed many times since).
Particularly helpful in following this case were the translated “online” court reports
of the trial, published in Italy by La Gazzetta dedo Sport and Corriere Della Sera.
In the context of a conviction in relation to a possible boycott of future Italian F1
races, it should be appreciated that given the massive following that the Ferrari
team in particular have in Italy, (and to a slightly lesser degree, Italian drivers of
non Italian teams) this would be a huge sanction, the importance of which, is
surely not lost on the Italian authorities, even at this critical late stage in the trial,
which resumed after the summer break, during September.
Although some are arguing that F1 drivers are well aware of the risks involved,
are paid huge sums of money to drive what are effectively design prototypes and
consequently, must take it as it comes, this argument is not valid and one I
personally disagree with. The reality is that if the team engineers were indeed
negligent or reckless in carrying out modifications to the car, which I do not
accept (in fact, Senna’s team mate Damon Hill’s car was also similarly modified)
then it is likely that they will and should be found culpable.
I find it inconceivable that given the vast sums of money spent by F1 teams in
designing and manufacturing race cars, the high calibre of the Engineers
involved and the overall dedication to perfection within F1 generally, that they
would risk losing two priceless drivers not to mention two cars (worth approx.
£700,000 each) on a modification carried out negligently or recklessly, to such an
important and vital component as a steering column.
The F1 authorities have gone to great lengths to keep F1 relatively safe by
constantly restricting team engineers in the area of vehicle top speed and a
further round of controversial regulations, particularly in relation to tyres and car
widths, are being actively proposed.
Some of the drivers reaction to these new proposals and technical changes are
lukewarm at best if not openly hostile and some have said that the tyre proposals
in particular would be a retrograde step in terms of safety. I would make the point
that in order that F1 maintains it’s huge following as a spectator sport, of which
high speed is an important factor, current speeds can safely remain if tracks were
suitably modified to include additional run off areas, gravel traps and increased
impact absorption devices. Some concrete walls should have no place in F1.
Liam Cotter. 1997