In a 1980 interview with Roger Ebert, Stallone mentioned problems with stunts he wanted to perform himself in "Nighthawks". In the scene where he jumps onto a moving train and kicks out the wire-reinforced window, the window broke easily and knocked him off balance. Stallone has had a lifelong fear of heights and said about the helicopter stunt, "I've never been so scared in my life". According to the actor, he spent 15 weeks in near-total seclusion in his hotel room between scenes and it was the most stressful time of his life.