that the unusually high-pitched voice of Bob in his broadcast was due to inhaling helium, and locates him in the envelope of the Duff Blimp. Bob, having lost his patience thanks to Krusty, tries to detonate the bomb, which turns out to be a dud, because it had passed the expiration date of November 1959. Lisa alerts the police to Bob's location using the blimp's variable-message sign, but Bob deflates the blimp and kidnaps Bart, before stealing the original Wright Brothers aircraft, which had been an exhibit at the air show. Holding a knife against Bart's throat, Bob attempts to carry out a deadly kamikaze attack against the civil defense shack where Krusty is hiding and kill him, Bart, and himself, but the slow-moving plane ends up merely bouncing harmlessly off the shack. The authorities quickly arrest Bob and take him back into custody while Bart is reunited with the rest of the family. Production "Sideshow Bob's Last Gleaming" was the fifth episode of The Simpsons to feature Sideshow Bob as the main character, after "Krusty Gets Busted", "Black Widower", "Cape Feare", and "Sideshow Bob Roberts". Executive producers Bill Oakley and Josh Weinstein believed that every season of the show should contain an episode featuring Bob. However, Bob had already been in four episodes and the writers were having a difficult time coming up with new ways to include him. The first draft of the episode was written by Spike Feresten, a freelance writer who later became known for his work on Seinfeld. Although he received credit for the episode, the writing staff completely rewrote the episode and very little of Feresten's original script was left in the episode. Oakley describes the episode as "one of the most arduous rewrites in the history of the show" because much of the dialogue had to be re-written. "Sideshow Bob's Last Gleaming" was the first episode of The Simpsons to be directed by Dominic Polcino. Polcino had worked as an assistant director on the show and had left the show, but was offered a chance to be a director. He describes the episode as a "tough one to start with", especially the scenes with the Wright Flyer.<ref name="Polcino">Polcino, Dominic (2005). Commentary for "Sideshow Bob's Last Gleaming", in The Simpsons: The Complete Seventh SeasoreturnVD]. 20th Century Fox.</ref> An early version of the script featured a longer scene at the air show that featured Hans