The most mysterious accidents in the history of Le Mans: the explanation

All saw racing cars doing flips, but why did it happen?

Races in Le Mans and other competitions where the participants are the car classes GT1 and LMP in the past there were sometimes literally dizzying curiosities, which, unfortunately, often could cost the riders or someone from the staff serving the race of life. The fact is that at speeds under 300 km/h and above, racing car rose into the air like wingless birds and was doing one of the most difficult elements of acrobatics – back flip! It seems unreal, but there is a simple reason that easily explains why this happens. Or rather, it did happen.

If you’ve seen the cutting the most burning moments with the “24 hours of Le Mans” in 1999, you will no doubt remember the spectacular crash Peter Dubreka turn in front of the famous “Indianapolis corner”, where his Mercedes CLR took off, seemingly for no apparent reason, several times turned over in air, it landed somewhere between the trees. Exactly the same happened with his teammate, mark Webber, in the same place during qualifying and then the race on time before turn Mulsan corner.

A precursor flight racing CLR was a similar disaster in the introductory part of the racing series “Petit Le Mans” the year before. Porsche 911 GT1 of Yannick Dalmas went into the air after the supercar taking off on a hill. In the air vehicle overturned once before landing on the back. The same thing happened with bill Oberlin on the same race two years later. He was driving a BMW V12 LMR.

The consequences of the crash of Webber near Multan corner in practice in Le Mans in 1999

So why all these cars were almost identical accident, at one and the same time? Surely there is some correlation? It is really so. As explained by Mike Fernie YouTube channel “Drivetribe” in the following video, this is due to the aerodynamic design of sports car racing of the highest level of that era.

Generally, any race car uses a negative pitch angle that can be described by the fact that the front of the car planted a bit below the rear part, increasing the aerodynamic frontal area of the car. This helps to generate downforce and, thus, to increase the speed of cornering.

However, the 911 GT1, CLR, V12 LMR and was in fact designed solely for racing Le Mans, which is an important element of competition is not only the immediate endurance race, but also the highest speed of the route. In 1990-e years is so high that the longest straight of the track “sarta” had to be split into three pieces two shikan. However, even it didn’t really affect the speed, it was still too high.

So, Porsche, and Mercedes, and also BMW is not saying a word made the basis for the more neutral pitch, reducing the frontal area in the name of higher speeds on the straights. And it worked, but there was one problem!

The fact that when climbing the hill, the pitch angle becomes positive in fact, that virtually could create lift under the front part of the car. Thus, in the above circumstances, the young man from the video as soon as the pitch angle Mercedes reached 2.4 degrees, downforce in the rear disappeared, and the car was up in the air.

After the collapse of Dubreka time of the race in 1999, Mercedes decided to withdraw from race two of its remaining car, and to this day the automaker did not return to Le Mans.

Although this Mercedes is quite strange, because, to prevent the recurrence of similar things, FIA has decreed that all prototypes had to be additionally equipped with vents in the front wings, to reduce the accumulated air pressure on the front axle. Front overhangs have also been reduced, since especially long overhang CLR exacerbate the adverse effects of increasing the pitch angle. And the rolling hill in Indianapolis was also smoothed. The problem was solved!

The vents on the front wing Audi R8 LMP1.

Miraculously, nobody was seriously injured in any of these accidents, and nothing like this has happened since Le Mans.