The prosecutor in the "Twilight Zone" involuntary manslaughter trial has filed a request that the jury be transported at night to the site of the 1982 film set helicopter accident to view a demonstration of special-effects explosions similar to those that led to the deaths of actor Vic Morrow and two children. Deputy Dist. Atty. Lea Purwin D'Agostino also requested that the jury be transported to Long Beach to watch a helicopter hover 24 feet off the ground, the height of the aircraft that was hit by the explosions during the fatal sequence. Los Angeles Superior Court Judge Roger W. Boren will rule on the trips, which D'Agostino termed "imperative," after an as yet unscheduled court hearing. A defense attorney for film director John Landis, one of five defendants in the case, called the prosecutor's proposal "patently absurd," since the jury already viewed extensive film footage of the accident.