A gust was to blame for triggering the sequence of events that ultimately led to the Black Foils and French crashing during the third race of SailGP’s return to Auckland.
The two boats were written off for the rest of the weekend after a high-speed collision which saw injured sailors from each team taken to Auckland Hospital.
New Zealand grinder Louis Sinclair had compound fractures in both legs, requiring surgery on his right after he was trapped inside his cockpit after the crash. He was discharged last Wednesday.
French strategist Manon Audinet was hospitalised with concerns around abdominal injuries after being thrown in her cockpit with enough force to break the steering wheel. She also suffered a minor hand injury. After being kept in the hospital for observation, Audinet was discharged last Friday.
After a review of the incident, SailGP engineering teams determined a sudden increase in wind speed caused the boat to accelerate, which saw the ride height of the boat rise. That saw the leeward foil – the side sheltered from the wind – break the surface, triggering a side slip.
The review found that the rudder angle increased as the Black Foils tried to regain control, losing effective flow. The windward bow submerging then saw a round-up and rapid deceleration, giving the oncoming French team no time or space to avoid a crash.
The Black Foils were travelling at 90km/h when the gust hit, while the French were sailing at roughly 86km/h.
“The data shows the boat accelerated quickly and rose high on its foils,” SailGP director of performance engineering Alex Reid said.
“Once the leeward foil pierced the surface, the boat entered a side slip where the foil began generating unwanted lift through leeway rather than via rake.
“At that point, the dynamics of the boat changed very quickly. Control inputs from the flight controller were still being applied, but we believe the physics of the slide meant the boat could not be brought down in time.”
The review, which involved performance data, onboard telemetry, simulator recreations and video analysis, found there were no issues with the Black Foils’ F50 which led to the crash.
It had been a question posed by some after the vessel had to be repaired in the month between the Perth and Auckland events, as it was damaged in a crash in the first race of the season.
“There is no evidence of a mechanical or software failure in the systems leading up to the incident,” Reid said.
“What we see in the data is a very fast chain of aerodynamic and hydrodynamic events that pushed the boat beyond its controllable envelope at that moment.”
After a penalty hearing, the initial ruling that the Black Foils were at fault was upheld and the team was docked eight penalty points for the event.
That saw the New Zealanders drop from 18 points to 10 after a hot start to the regatta, which was good enough for them to finish in eighth and pick up two season points.
France finished on 17 points after the first two races, which was enough for them to finish third. However, as they were unable to compete in the second day of racing they were bumped down to fourth and took seven points toward their season total.
The Black Foils and France were still able to be a factor in the event standings as day two saw the league switch to a split-fleet format, which saw the points on offer per race halved. That meant teams were only picking up a maximum of five in each of their two races.
“It’s a nice format, but I think it’s tough when you change from the Saturday to the Sunday, because you can score a lot less points in the split fleet,” Swiss driver Sebastien Schneiter told the Herald after Sunday’s racing.
“But overall, it’s not a bad format and if we have more boats in the future I think it’s definitely something that is quite good.
“Actually, the racing, from a sailor’s point of view, is almost more interesting because you’ve got a bit more space to play the shifts rather than just the traffic.”
Both the French and New Zealand teams will miss this weekend’s regatta in Sydney as repairs continue. The French, found not to be at fault for the incident, will get priority in the repair process.
Christopher Reive joined the Herald sports team in 2017, bringing the same versatility to his coverage as he does to his sports viewing habits.