The FIA has officially concluded its thorough investigation of the Formula 2 crash that claimed the life of Anthoine Hubert in August of 2019.
Juan Manuel Correa suffered serious leg injuries following the incident, and had to undergo a number of surgeries in order to save his right leg.
The FIA's examination focused on four cars that were involved - Giuliano Alesi, Ralph Boschung, Anthoine Hubert and Juan Manuel Correa.
The investigation has determined that no driver involved in the crash failed to react appropriately to the yellow flags that were deployed on the build-up to the incident.
On lap two of Saturday's Feature Race at Spa-Francorchamps, Trident's Giuliano Alesi lost control of his car on the exit of Eau Rouge, which saw him hit the barriers 1.9 seconds after losing command.
The FIA stated that a probable explanation for the loss of control was a decrease of internal pressure of the right rear tyre.
Following Alesi's crash, debris was spread onto the circuit, and in an attempt to avoid it, Ralph Boschung and Anthoine Hubert moved to the right of the circuit at Turn 4. The reaction time of both drivers was faster than that of the marshalls' deployment of yellow flags, which occurred 1.8 seconds after Alesi's impact.
It was found that Boschung slowed considerably more abruptly than Hubert, which caused the latter to make contact with Boschung, resulting in a lost front wing for Hubert and a right rear tyre puncture for Boschung.
With no control over his car, Hubert headed towards the barriers at Turn 4 at 262 km/h, impacting at a recorded speed of 216 km/h and generating a peak force equivalent to 33.7g.
Hubert's car was ejected back onto the racing line, with the left side of his chassis pointing towards the cars that were coming through the corner.
Juan Manuel Correa then came through the Eau Rouge/Raidillon sequence and hit the debris from Alesi's car, 1.5 seconds after the marshalls deployed the yellow flags. This contact resulted in a broken suspension for Correa, who was sent into the path of Hubert's stationary car.
Correa car hit the BWT Arden machine of Hubert at approximately 86 degrees and at a speed of 218 km/h. Correa and Hubert's cars experienced peak forces equivalent to 65.1g and 81.8g.
Following the impact, Hubert's car travelled at 105.4 km/h, striking the barrier for a second time. Double waved yellow flags were deployed 2.5 seconds after the crash, before red flags were flown 2.7 seconds later.
The medical and rescue response sprung into action 12 seconds after Alesi's car lost control, and Hubert was attended to 54 seconds following the deployment of the red flag.
Correa was seen by medical staff 69 seconds after the red flag, while a small fire was put out at the back of his car 16 seconds after the red flag.
1. A chain of events resulted in a protracted and complex crash sequence involving four drivers, which ultimately led to a high-speed ‘T-Bone’ type impact between the cars of Juan Manuel Correa and Anthoine Hubert.
2. The dynamics of the car-to-car impact in terms of speed and trajectory were such that an extremely high level of energy was transferred and dissipated, translating into non-survivable trauma to Anthoine Hubert and very serious injuries to Juan Manuel Correa.
3. There was no single specific cause but multiple contributory factors giving rise to the severity of the accident were identified, following a detailed analysis of the various phases of the accident.
4. The investigation found no evidence that any driver failed to react appropriately in response to the yellow flag signal or to the circumstances on track.
5. The reaction of marshals and race control in deploying signaling and rescue services in relation to the accident is considered timely and good.
The FIA added: "Safety improvement is a continuous process, therefore conclusions drawn from this accident and others like it from around the world will be integrated into the ongoing work of the FIA to further develop motor sport safety.
"In 2019 the FIA Safety department conducted investigations into 28 serious and fatal accidents related to circuit racing, supported by the ASN (National Sporting Authority) in each country."