A seminar with input from NASA and Volpe scientists, held next week at HAI Heli-Expo 2017 in Dallas, Texas, will introduce pilots to new tactics and techniques to lower their noise footprint — a key issue for those working in urban or other noise-sensitive areas.
The seminar — Fly Neighborly: Techniques for Noise Abatement — represents the first steps of a three-year HAI initiative to present on quiet flying techniques, as part of the association’s ongoing “Fly Neighborly” campaign.
The presentation is based on a white paper by David Bjellos, aviation manager at Agro-Industrial Management, Inc. (and a member of the HAI board of directors). The white paper incorporates research and data from noise experts at NASA, Volpe, and independent consultants, as well as from Dr. Scott Burgess, assistant professor at Embry-Riddle Aeronautical University – Worldwide.
Presented by Bjellos and Burgess, the seminar will begin by looking at how routings can be optimized to avoid noise-sensitive areas.
“We emit what we call a noise footprint, and it’s dependent on a few things — temperature, humidity, density altitude, speed, [and] weight,” said Bjellos. “If we know where that noise footprint is being projected, we can fly the aircraft along a path that puts the noise footprint over a place like a highway or someplace where it’s not going to affect as many people.”
The second part of the presentation will look at techniques to maneuver aircraft to reduce blade vortex interaction (BVI) and impulsive noise.
“For example: a descending, decelerating left turn, in a left-hand turning rotor system, is quieter than a descending, decelerating right hand turn,” said Bjellos. “A collective climb is quieter than a cyclic climb. Flying a little higher, a little slower, and working routings with your local [air traffic control] are the key for this year’s initiative.”
The presentation, held from 8 a.m. to 10 a.m. on March 8 at the Kay Bailey Hutchinson Convention Center (room C146), is part of the HFI Rotor Safety Challenge, and is free to all registered Heli-Expo attendees and exhibitors. Bjellos said it will incorporate videos created by Volpe that show, from a pilot’s viewpoint, the location of noise hotspots on the ground during different flight profiles.
“We think it’s going to be the most scientifically focused way for pilots to figure out how to fly quietly based upon the limitations of the rotor systems that we currently have,” he said.
Bjellos added that his flight department in Palm Beach, Florida, has been incorporating the techniques for over a year, and said it had made an impact on the community noise board with fewer rotorcraft noise complaints.
NASA will be conducting more noise trials this spring, said Bjellos, and it will have data on more modern aircraft types (including the Airbus H130, Bell 407, and Sikorsky S-76 and S-92) that will apply to a large number of Heli-Expo attendees. Eventually, HAI hopes these trials will allow them to share aircraft-specific techniques to further reduce noise.
