<prompt> Bhala okuqhubekayo kwalesi sigaba - UFerrari waqala isizini ka-1991 enethemba elikhulu lokuwina ubuqhawe. UJean Alesi wasayina inkontileka neScuderia lapho uNigel Mansell ebuyela eqenjini likaWilliams. Umphumela omuhle kakhulu we-642 kwaba indawo yesibili eyathathwa u-Alain Prost e-1991 United States Grand Prix, eyayibanjelwe esifundeni somgwaqo sasePhoenix. I-642 yathathelwa indawo yiFerrari 643 eGrand Prix yaseFrance ngo-1991  <response>: . futhi. 