season. During the Canadian Grand Prix, Prost's Olivier Panis crashed heavily and broke his leg. He was replaced by Minardi driver Jarno Trulli, who in turn was replaced by Tarso Marques, who had also made some appearances for the Minardi team the previous year. Panis missed seven races before returning at the Luxembourg Grand Prix, while Trulli would join him as a full-time Prost driver in 1998. Between the Canadian and French Grands Prix, Gianni Morbidelli had an accident in testing and broke his arm, meaning Sauber had to make their second substitution of the year. They brought in test driver Norberto Fontana, who completed the next three races before Morbidelli's return at the 1997 Hungarian Grand Prix. Morbidelli suffered another testing accident following the Japanese Grand Prix, so Fontana competed again at the season-ending European Grand Prix. Calendar The following seventeen Grands Prix took place in 1997. Calendar changes The Austrian Grand Prix returned to the calendar after a nine-year absence. The Luxembourg Grand Prix was added to the world championship for the first time, after being held as a non-championship race from 1949 until 1952. The Portuguese Grand Prix was originally scheduled as the final round of the season, to be held at the Estoril circuit on 26 October. It was cancelled and replaced by the European Grand Prix after the owners of the Estoril circuit failed to make requested changes to it. Season summary The season started in Australia, with Canadian Jacques Villeneuve taking the first pole position of the season. The moment was short-lived, however, as Villeneuve was out of the race at the first corner after colliding with Johnny Herbert. McLaren's David Coulthard went on to win the race, the second of his career, with Michael Schumacher finishing second and Mika Häkkinen finishing in third place. Villeneuve once again took pole position in Brazil, and once again he was off at the first corner. Luckily for him the race was restarted, and the Canadian took the lead on lap 49 from Gerhard Berger. The Austrian finished second and Olivier Panis continued his impressive form from 1996 with third place. For the third time in a row, Jacques Villeneuve was again on pole position for Argentina. However, he was spared another first corner collision, and instead it was Michael Schumacher who collided with Rubens Barrichello. With Schumacher out, Eddie Irvine went on to challenge Villeneuve for