Hopeful manufacturers of supersonic business jets–Aerion, Gulfstream and Supersonic Aerospace International–are encouraged by an updated FAA policy statement issued last week to align noise limits for future civil supersonic aircraft with current Stage 4 noise regulations. According to the FAA, this action is intended to provide guidance on noise limits to manufacturers that are considering designs for supersonic aircraft. Interest in supersonic aircraft technology has not disappeared. Would-be manufacturers hope it’s a “foot in the door” for regulations allowing low-boom or boomless supersonic flight over land in the U.S. “Current research is dedicated toward reducing the impact of sonic booms before they reach the ground, in an effort to make overland flight acceptable,” the FAA policy states. “Recent research has produced promising results for low boom intensity, and has renewed interest in developing supersonic civil aircraft that could be considered environmentally acceptable for supersonic flight over land.” Quiet Aerospace CEO J. Michael Paulson told AIN, “I was very pleased to see the statement regarding supersonic flight over land. Obviously, we are excited about the opportunity this gives our revolutionary ‘quiet’ supersonic aircraft [to achieve] supersonic overland permission.”