The impact of the Federal Aviation Regulations (FARs) on fuel conservation in the air-transportation system. To date there exist over 89 identifiable fuel-conservation program and research areas. Operational constraints in the areas of FARs and Air Traffic Control (ATC), which hinder further fuel savings in any of the 89 program and research areas, are identified. The nature of this investigation presents an update of analyses from previous FAA, DOE, and NASA publications from a DOE viewpoint. The short duration and cost constraints of this study did not allow an assessment of safety, social, or any of the broader impacts of the regulations. However, this study was not intended to solve all of the regulatory problems. Rather, this was a cur...