1. CHAPTER 45

2. ... describes the beginning of the race ...

3.

4. ...Over the radio, Damon was calling for information: What the hell's happened? How is he? What's happened?" - But we didn't know. The only information we had came from what we saw on the screens lining the pit wall. Our driver on a stretcher. No movement. No information.

5. ...

6. The race began again and we were forced to refocus. The helicopter took Ayrton to hospital. Schumacher won, Damon finished sixth.

7.

8. The news came through at the airport. Ayrton was dead.

9.

10.

11. CHAPTER 46

12.

13. Frank's aircraft flew us back to Kidlington, north of Oxford. I don't think any of us spoke. I really can't recall. Only that Marigold met me at Kidlington and drove me home, knowing I'd be in no fit state to drive myself.

14.

15. She'd arranged for the local pub to deliver beer to the house, so I could have a few drinks to unwind. It didn't work, but it was a nice thought. It was a warm evening, I can remember that, although it was only May.

16.

17. What I felt as I drank my beers and then lay awake in bed that night was an overwhelming sense of loss and, much more than that, waste. Even back then you knew Ayrton was destined for great - even greater — things. People had speculated that he might be President of Brazil one day. Was it all worth it, just to watch a bunch of cars racing around a track on a Sunday afternoon? Even now, twenty-something years later, I struggle to talk about it without my voice wavering.

18.

19. The next day was a Bank Holiday Monday. I went into Williams with other key engineers to see if we could understand what had happened. Was it a design fault that had caused the accident? Tamburello was difficult but flat, the kind of big-balls corner that a driver should be able to take without lifting off the throttle. A driver of Ayrton's ability shouldn't have had a problem with a corner like that.

20.

21. We reviewed what footage we had, and it was clear that the steering wheel had come off. You could see the wheel and the end of the steering column lying beside the car in the TV footage. The obvious conclusion was that the steering column had snapped and that was the cause of the accident.

22.

23. Patrick was technical director and therefore had technical charge of the team. I was chief designer and responsible for the overall designofthoefctahre. And though neither of us were involved in the design or manufacture actual components, as leaders of the ship, we had to assume responsibility. Put simply, if the steering column snapping was the cause of the accident, it Put simply, was our fault, since we were responsible for putting in place the systems needed to avoid such a thing happening.

24.

25. It would take a long time before we identified the missing pieces of the jigsaw. I would spend the following months — as it turned out, years —having to watch the accident over and over again: the pictures from Schumacher's car, the circuit TV feed, the race footage, marrying it to the data, trying to understand what had happened, why Ayrton had died that afternoon.

26.

27. The FW16 had two on-board computers. One controlled the engine and was supplied by Magneti Marelli, the other was a Williams-built ECU that Steve Wise, the head of electronics at Williams, had developed to control the active suspension system in 1992.

28.

29. Computers had less of a function after the great regulations purge outlawed our electronically controlled systems; however, they did provide some degree of 'data logging', namely using sensors around the car as a diagnostic feature, monitoring such things as loads on the suspension, the gear change, throttle position, engine rpm, wheel speeds, damper positions — areas that gave us information on what the car was doing around the lap.

30.

31. The Renault Marelli engine control unit had been largely destroyed in the accident, and the Williams control unit was badly damaged too, but we were able to extract some data from it. Importantly, what we were able to ascertain was throttle position, brake pressure and steering torque, and what we saw appeared to substantiate the theory that it was a steering column failure, because it showed the steering column torque falling to near zero. In other words, there was no steering input during this phase. This could either mean that Ayrton had chosen not to steer, or that he was unable to steer because the steering column had failed.

32.

33. Our feeling, however, that the steering column had been the main cause of the accident changed, however, when the F I A provided us with the on-board footage from Schumacher's car. This indicated that the rear of Ayrton's car had stepped out, which was the opposite to what would hap-pen if the steering column had failed. Obviously, if the steering fails, you expect the car to carry straight on. But if the rear of the car steps out, that can only be from a loss of rear grip, not from a loss of front grip.

34.

35. That seemed a bit peculiar. Coming from my oval-racing experience in the States, I knew that drivers in Super Speedway are often faced with this problem of the rear stepping out in high-speed corners. The usual method of trying to correct it is by applying opposite lock, i.e. in a left-hand turn, apply lock to the right. But if the car is stepping out in a snappy and harsh manner, the fear is that the rear will suddenly grip and whip the driver around in the opposite direction, resulting in a nose-first crash into a wall. Super Speedway drivers will often let a spin take place rather than risk this happening.

36.

37. So, did Ayrton suffer that type of Super Speedway accident where the rear loses and then suddenly regains grip and flings him to the outside wall? It can happen to the most experienced and greatest of the Super Speedway drivers in the States.

38.

39. Very quickly, the question became two-tiered: what caused Ayrton to leave the track in the first place, and, given that he was such an able driver, why was he unable to control it?

40.

41. We were able to time-match Schumacher's on-board footage with the data from the on-board computer, and what we established was that at the moment the rear of the car stepped out, Ayrton lifted his foot to about 40 per cent throttle and the steering torque dropped.

42.

43. Now, if you suddenly lose rear grip, that is exactly the reaction you'd expect a driver to make. He doesn't lift his foot fully off the throttle. What he's doing at that point is trying to maximise the grip of the rear tyres, which means trying to minimise the longitudinal force the rear tyres are trying to transmit, be it acceleration or braking, so that they have the maximum capacity for lateral grip. It looked like that's what Ayrton had done; by reducing steering torque he was effectively applying opposite lock, which, as I've said, is the usual way to correct the rear of a car that is stepping out.

44.

45. The data showed that Ayrton held that position of 40 per cent throttle and low level of steering torque for half a second, then got very heavily on the brake. All we saw after that was extremely high brake pressure as he left the track. Again then, the sequence of events consistent with the data is that the rear stepped out, Ayrton reacted, doing his best to hold the slide by reducing to 40 per cent throttle and reducing steering torque before realising after half a second that he'd lost control, after which he jumped on the brakes.

46.

47. The initial stepping out of the car was nothing to do with any steering column failure. There had to be another explanation for that.

48.

49. The safety car was an Opel Vectra, so the pace would have been very slow after the start/finish prang that showered the track with debris. After all those laps at such a slow pace, the tyres would have cooled and tyre pressures been extremely low at the restart, and that, without doubt, would have aggravated the bottoming that we saw.

50.

51. But this doesn't fully explain everything. In fact, it may be a red her-ring. Why, for example, did Ayrton's car spark as much on lap seven as it had on the previous lap, when tyre pressures should have become pro-gressively higher? The suspension components themselves all seemed to be fine, so the obvious conclusion is that the tyres were still under-inflated. But why? Their temperature and therefore pressure should have been back up to near normal after a full, hard racing lap.

52.

53. There is a photograph in Autosport (20 February 1997, page 6) that shows a piece of debris on the track, with Ayrton's car about to pass over it. His right front and right rear tyres were completely destroyed in the accident, so it was impossible to examine them and say for certain, but a piece of debris that size could easily have caused a slow puncture. The puncture would have caused the bottoming we saw, and that in turn would have caused the rear to step out as it lostgrip, since you've unloaded the tyres meaning that the weight of the car is now being taken on the skids, which have no lateral grip capability. Not only that but with the car now flat on the deck the diffuser would be completely stalled, resulting in the rear losing most of its downforce.

54.

55. For me, that offers an explanation as to why the rear suddenly stepped out, and it obviously caught Ayrton by surprise.

56.

57. Still, that bring us to the second question. Why, after the car had stepped out, did Ayrton fail to control it? Of all the drivers on thegrid, he was the most able to recover that situation. There are two possibilities here. 0ne is that the steering column failed at this point. The other is that as the car came off the back side of the hump pointing left, but with the front wheels still pointing straight ahead, the rear suddenly gripped and threw it sharply right.

58.

59. What we could see once we were allowed to inspect the steering column was that it did have a fatigue crack present, so it was going to fail sooner or later. It had fatigued roughly a third of the way around the circumference and the rest had snapped, either in the impact or from the pressure Ayrton exerted while trying to control the car after the rear stepped out. Where the steering column failed was where it had been locally reduced by 4mm in diameter.

60.

61. This led to the further question: would the remaining two-thirds of the column that had not fatigued have had enough strength to transmit the torque required to maintain normal driving? So we built a test rig con-sisting of the complete car steering system, and, with a saw, cut one-third of the way through the new column to represent the fatigued area. We then got a 'driver' to turn the steering wheel in order to achieve the highest pressure shown by the data recorder. The result was that, yes, even in this damaged state, the column had enough strength left in it. Following that result we conducted various tests, trying to marry data recovered from the ECU for pressure transducers across the steering rack and the steering column data with measurements on the rig. When the car left the edge of the circuit, it travelled across a very uneven boundary from circuit to apron, which put large pressure spikes across the rack with corresponding spikes in the column torque. The only way we could achieve the column torques on the rig was with the column still reasonably intact and thus able to trans-mit torque due to the rotational inertia of the steering wheel — put simply, a completely broken column could not be made to register any steering column torque readings.

62.

63. Now, I am responsible for following that request of Ayrton's to lower the steering wheel slightly to avoid him rubbing his knuckles on the inside of the chassis. I am responsible for giving the drawing office the instruction to that it would then lower it by 2mm, and when they came back to me to say

64. interfere with the FIA cockpit template, I instructed them to reduce the steering column diameter locally by 4mm.

65.

66. What I didn't do was look at the detailed drawing myself or have a proper checking system in place to make sure that it had been done in a safe manner. It's a simple, well-known law of engineering that to maintain stiff-ness and strength you have to increase wall thickness, but that wasn't done. The wall thickness was not increased.

67.

68. It's also a simple, well-known law of engineering that if you have a very sharp corner • a component, that causes an area of very high stress; and because of that stress, the component will eventually crack and fatigue; and that fatigue crack will propagate eventually around the whole component and cause failure.

69.

70. So there were two very bad pieces of engineering in that diameter reduction. Ultimately, Patrick and I were responsible for that.

71.

72. You question yourself. If you don't, you're a fool. The first thing you ask yourself is: Do I want to be involved in something where somebody can be killed as a result of a decision I have made? If you answer yes to that one, the second is: Do I accept that one of the design team for which I am responsible may make a mistake in the design of the car and the result of that mistake is that somebody may be killed? Prior to Imola, stupid as this may sound, I had never asked myself those questions.

73.

74. If you want to continue in motor racing, you have to square that with yourself. You have to be prepared to offer an affirmative to both of those questions because, try as you might, you can never ever guarantee that a mistake will not be made. Designing a racing car means pushing the boundaries of design. If you don't, it won't be competitive. Then there's the decision-making during the race. If a car is carrying damage for some reason, you have to make the decision: Do I tell a driver to retire the car or let him continue? Ifyou call it too conservatively, you simply retire the car for no good reason. If you've been too bullish, the driver could have an accident with unknown consequences. It's never an easy judgement.

75.

76. People ask me if I feel guilty about Ayrton. I do. I was one of the senior officers in a teamthat designed a car in which a great man was killed. Regardless of whether that steering column caused the accident or not, there is no escaping the fact that it was a bad piece of design that should never have been allowed to get on the car. The system that Patrick and I had in place was inadequate; that cannot be disputed. Our lack of a safety-checking system within the design office was exposed.

77.

78. So, in the immediate aftermath, Patrick and I discussed that and agreed we would have to go to a category system in which the safety-critical components, including the steering system, braking system, suspension parts and key aerodynamic components such as the front wing and rear wing — all the things that, if they failed, could cause an accident — should be submitted to an experienced stress engineer who would look at the drawings, make sure they were structurally sound and then countersign the drawing.

79.

80. What I feel the most guilt about, though, is not the possibility that steering column failure may have caused the accident, because I don't think it did, but the fact that I screwed up the aerodynamics of the car. I messed up the transition from active suspension back to passive and designed a car that was aerodynamically unstable, in which Ayrton attempted to do things the car was not capable of doing. Whether he did or didn't get a puncture, his taking the inside, faster-but-bumpier line in a car that was aero-dynamically unstable would have made the car difficult to control, even for him.

81.

82. I think now, If only we'd had more time. By Imola, I understood the prob-lem• I just needed time to develop the wind tunnel model and then the parts to go on the car, to give Ayrton a car that was worthy of him. Time denied us all that chance.

CHAPTER 45 ... describes the beginning of the race ... ...Over the radio, Damon was calling for information: What the hell's happened? How is he? What's happened?" - But we didn't know. The only information we had came from what we saw on the screens lining the pit wall. Our driver on a stretcher. No movement. No information. ... The race began again and we were forced to refocus. The helicopter took Ayrton to hospital. Schumacher won, Damon finished sixth. The news came through at the airport. Ayrton was dead. CHAPTER 46 Frank's aircraft flew us back to Kidlington, north of Oxford. I don't think any of us spoke. I really can't recall. Only that Marigold met me at Kidlington and drove me home, knowing I'd be in no fit state to drive myself. She'd arranged for the local pub to deliver beer to the house, so I could have a few drinks to unwind. It didn't work, but it was a nice thought. It was a warm evening, I can remember that, although it was only May. What I felt as I drank my beers and then lay awake in bed that night was an overwhelming sense of loss and, much more than that, waste. Even back then you knew Ayrton was destined for great - even greater — things. People had speculated that he might be President of Brazil one day. Was it all worth it, just to watch a bunch of cars racing around a track on a Sunday afternoon? Even now, twenty-something years later, I struggle to talk about it without my voice wavering. The next day was a Bank Holiday Monday. I went into Williams with other key engineers to see if we could understand what had happened. Was it a design fault that had caused the accident? Tamburello was difficult but flat, the kind of big-balls corner that a driver should be able to take without lifting off the throttle. A driver of Ayrton's ability shouldn't have had a problem with a corner like that. We reviewed what footage we had, and it was clear that the steering wheel had come off. You could see the wheel and the end of the steering column lying beside the car in the TV footage. The obvious conclusion was that the steering column had snapped and that was the cause of the accident. Patrick was technical director and therefore had technical charge of the team. I was chief designer and responsible for the overall designofthoefctahre. And though neither of us were involved in the design or manufacture actual components, as leaders of the ship, we had to assume responsibility. Put simply, if the steering column snapping was the cause of the accident, it Put simply, was our fault, since we were responsible for putting in place the systems needed to avoid such a thing happening. It would take a long time before we identified the missing pieces of the jigsaw. I would spend the following months — as it turned out, years —having to watch the accident over and over again: the pictures from Schumacher's car, the circuit TV feed, the race footage, marrying it to the data, trying to understand what had happened, why Ayrton had died that afternoon. The FW16 had two on-board computers. One controlled the engine and was supplied by Magneti Marelli, the other was a Williams-built ECU that Steve Wise, the head of electronics at Williams, had developed to control the active suspension system in 1992. Computers had less of a function after the great regulations purge outlawed our electronically controlled systems; however, they did provide some degree of 'data logging', namely using sensors around the car as a diagnostic feature, monitoring such things as loads on the suspension, the gear change, throttle position, engine rpm, wheel speeds, damper positions — areas that gave us information on what the car was doing around the lap. The Renault Marelli engine control unit had been largely destroyed in the accident, and the Williams control unit was badly damaged too, but we were able to extract some data from it. Importantly, what we were able to ascertain was throttle position, brake pressure and steering torque, and what we saw appeared to substantiate the theory that it was a steering column failure, because it showed the steering column torque falling to near zero. In other words, there was no steering input during this phase. This could either mean that Ayrton had chosen not to steer, or that he was unable to steer because the steering column had failed. Our feeling, however, that the steering column had been the main cause of the accident changed, however, when the F I A provided us with the on-board footage from Schumacher's car. This indicated that the rear of Ayrton's car had stepped out, which was the opposite to what would hap-pen if the steering column had failed. Obviously, if the steering fails, you expect the car to carry straight on. But if the rear of the car steps out, that can only be from a loss of rear grip, not from a loss of front grip. That seemed a bit peculiar. Coming from my oval-racing experience in the States, I knew that drivers in Super Speedway are often faced with this problem of the rear stepping out in high-speed corners. The usual method of trying to correct it is by applying opposite lock, i.e. in a left-hand turn, apply lock to the right. But if the car is stepping out in a snappy and harsh manner, the fear is that the rear will suddenly grip and whip the driver around in the opposite direction, resulting in a nose-first crash into a wall. Super Speedway drivers will often let a spin take place rather than risk this happening. So, did Ayrton suffer that type of Super Speedway accident where the rear loses and then suddenly regains grip and flings him to the outside wall? It can happen to the most experienced and greatest of the Super Speedway drivers in the States. Very quickly, the question became two-tiered: what caused Ayrton to leave the track in the first place, and, given that he was such an able driver, why was he unable to control it? We were able to time-match Schumacher's on-board footage with the data from the on-board computer, and what we established was that at the moment the rear of the car stepped out, Ayrton lifted his foot to about 40 per cent throttle and the steering torque dropped. Now, if you suddenly lose rear grip, that is exactly the reaction you'd expect a driver to make. He doesn't lift his foot fully off the throttle. What he's doing at that point is trying to maximise the grip of the rear tyres, which means trying to minimise the longitudinal force the rear tyres are trying to transmit, be it acceleration or braking, so that they have the maximum capacity for lateral grip. It looked like that's what Ayrton had done; by reducing steering torque he was effectively applying opposite lock, which, as I've said, is the usual way to correct the rear of a car that is stepping out. The data showed that Ayrton held that position of 40 per cent throttle and low level of steering torque for half a second, then got very heavily on the brake. All we saw after that was extremely high brake pressure as he left the track. Again then, the sequence of events consistent with the data is that the rear stepped out, Ayrton reacted, doing his best to hold the slide by reducing to 40 per cent throttle and reducing steering torque before realising after half a second that he'd lost control, after which he jumped on the brakes. The initial stepping out of the car was nothing to do with any steering column failure. There had to be another explanation for that. The safety car was an Opel Vectra, so the pace would have been very slow after the start/finish prang that showered the track with debris. After all those laps at such a slow pace, the tyres would have cooled and tyre pressures been extremely low at the restart, and that, without doubt, would have aggravated the bottoming that we saw. But this doesn't fully explain everything. In fact, it may be a red her-ring. Why, for example, did Ayrton's car spark as much on lap seven as it had on the previous lap, when tyre pressures should have become pro-gressively higher? The suspension components themselves all seemed to be fine, so the obvious conclusion is that the tyres were still under-inflated. But why? Their temperature and therefore pressure should have been back up to near normal after a full, hard racing lap. There is a photograph in Autosport (20 February 1997, page 6) that shows a piece of debris on the track, with Ayrton's car about to pass over it. His right front and right rear tyres were completely destroyed in the accident, so it was impossible to examine them and say for certain, but a piece of debris that size could easily have caused a slow puncture. The puncture would have caused the bottoming we saw, and that in turn would have caused the rear to step out as it lostgrip, since you've unloaded the tyres meaning that the weight of the car is now being taken on the skids, which have no lateral grip capability. Not only that but with the car now flat on the deck the diffuser would be completely stalled, resulting in the rear losing most of its downforce. For me, that offers an explanation as to why the rear suddenly stepped out, and it obviously caught Ayrton by surprise. Still, that bring us to the second question. Why, after the car had stepped out, did Ayrton fail to control it? Of all the drivers on thegrid, he was the most able to recover that situation. There are two possibilities here. 0ne is that the steering column failed at this point. The other is that as the car came off the back side of the hump pointing left, but with the front wheels still pointing straight ahead, the rear suddenly gripped and threw it sharply right. What we could see once we were allowed to inspect the steering column was that it did have a fatigue crack present, so it was going to fail sooner or later. It had fatigued roughly a third of the way around the circumference and the rest had snapped, either in the impact or from the pressure Ayrton exerted while trying to control the car after the rear stepped out. Where the steering column failed was where it had been locally reduced by 4mm in diameter. This led to the further question: would the remaining two-thirds of the column that had not fatigued have had enough strength to transmit the torque required to maintain normal driving? So we built a test rig con-sisting of the complete car steering system, and, with a saw, cut one-third of the way through the new column to represent the fatigued area. We then got a 'driver' to turn the steering wheel in order to achieve the highest pressure shown by the data recorder. The result was that, yes, even in this damaged state, the column had enough strength left in it. Following that result we conducted various tests, trying to marry data recovered from the ECU for pressure transducers across the steering rack and the steering column data with measurements on the rig. When the car left the edge of the circuit, it travelled across a very uneven boundary from circuit to apron, which put large pressure spikes across the rack with corresponding spikes in the column torque. The only way we could achieve the column torques on the rig was with the column still reasonably intact and thus able to trans-mit torque due to the rotational inertia of the steering wheel — put simply, a completely broken column could not be made to register any steering column torque readings. Now, I am responsible for following that request of Ayrton's to lower the steering wheel slightly to avoid him rubbing his knuckles on the inside of the chassis. I am responsible for giving the drawing office the instruction to that it would then lower it by 2mm, and when they came back to me to say interfere with the FIA cockpit template, I instructed them to reduce the steering column diameter locally by 4mm. What I didn't do was look at the detailed drawing myself or have a proper checking system in place to make sure that it had been done in a safe manner. It's a simple, well-known law of engineering that to maintain stiff-ness and strength you have to increase wall thickness, but that wasn't done. The wall thickness was not increased. It's also a simple, well-known law of engineering that if you have a very sharp corner • a component, that causes an area of very high stress; and because of that stress, the component will eventually crack and fatigue; and that fatigue crack will propagate eventually around the whole component and cause failure. So there were two very bad pieces of engineering in that diameter reduction. Ultimately, Patrick and I were responsible for that. You question yourself. If you don't, you're a fool. The first thing you ask yourself is: Do I want to be involved in something where somebody can be killed as a result of a decision I have made? If you answer yes to that one, the second is: Do I accept that one of the design team for which I am responsible may make a mistake in the design of the car and the result of that mistake is that somebody may be killed? Prior to Imola, stupid as this may sound, I had never asked myself those questions. If you want to continue in motor racing, you have to square that with yourself. You have to be prepared to offer an affirmative to both of those questions because, try as you might, you can never ever guarantee that a mistake will not be made. Designing a racing car means pushing the boundaries of design. If you don't, it won't be competitive. Then there's the decision-making during the race. If a car is carrying damage for some reason, you have to make the decision: Do I tell a driver to retire the car or let him continue? Ifyou call it too conservatively, you simply retire the car for no good reason. If you've been too bullish, the driver could have an accident with unknown consequences. It's never an easy judgement. People ask me if I feel guilty about Ayrton. I do. I was one of the senior officers in a teamthat designed a car in which a great man was killed. Regardless of whether that steering column caused the accident or not, there is no escaping the fact that it was a bad piece of design that should never have been allowed to get on the car. The system that Patrick and I had in place was inadequate; that cannot be disputed. Our lack of a safety-checking system within the design office was exposed. So, in the immediate aftermath, Patrick and I discussed that and agreed we would have to go to a category system in which the safety-critical components, including the steering system, braking system, suspension parts and key aerodynamic components such as the front wing and rear wing — all the things that, if they failed, could cause an accident — should be submitted to an experienced stress engineer who would look at the drawings, make sure they were structurally sound and then countersign the drawing. What I feel the most guilt about, though, is not the possibility that steering column failure may have caused the accident, because I don't think it did, but the fact that I screwed up the aerodynamics of the car. I messed up the transition from active suspension back to passive and designed a car that was aerodynamically unstable, in which Ayrton attempted to do things the car was not capable of doing. Whether he did or didn't get a puncture, his taking the inside, faster-but-bumpier line in a car that was aero-dynamically unstable would have made the car difficult to control, even for him. I think now, If only we'd had more time. By Imola, I understood the prob-lem• I just needed time to develop the wind tunnel model and then the parts to go on the car, to give Ayrton a car that was worthy of him. Time denied us all that chance.