Presented to:

By:

Date:

Federal Aviation

Administration

Noise Research

E&E REDAC Subcommittee

Joseph DiPardo, AEE 

March, 2018
Federal Aviation

Administration

Approach: 2,000 m

from threshold

Landing Takeoff Cycle

Sideline: 450 m 

from runway edge

Flyover: 6,500 m 

from brakes off

Undercarriage

Engine Fan & Jet Exhaust

High lift system

Aircraft Noise

Community Exposure

All noise sources contribute 

to acoustic signature – both 

at takeoff and during landing

Community exposure set by 

aircraft types and operational 

tempo over day and night

Community Noise from Aircraft

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Federal Aviation

Administration

Commercial Aircraft Noise Evolution

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Federal Aviation

Administration

Noise Reduction through Technology

• Noise improvements have come with fuel efficiency gains

• Increased engine bypass ratio

• Simplified high lift systems

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Boeing 747-400 Boeing 747-8

DC-8 Boeing 787

Images from airliners.net
Federal Aviation

Administration

Historical Trends in Noise Exposure and Enplanements

A factor of 20 decrease in community noise exposure has been 

achieved despite a four-fold increase in passenger enplanements,

but it has also been accompanied by increased community concerns

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Federal Aviation

Administration

Equivalent Operations for DNL = 65

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100 Events/Day SEL 94.4 dBA = 65 DNL

10 Events/Day SEL 104.4 dBA = 65 DNL

1 Event/Day SEL 114.4 dBA = 65 DNL Car Horn

Chain Saw

Lawn Mower

DNL Metric

• DNL metric provides cumulative 

noise exposure to many individual 

noise events

• Can reach given DNL with single 

loud noise event or many quieter 

noise events 

Aircraft Noise over Time

• Aircraft noise from 1970s is 

different than aircraft noise today

• Aircraft from 1970s produced the 

same acoustic energy as 10 to 30 

aircraft operations today

Equivalent DNL

• A few, but relatively loud, events in 

1970s would result in DNL 65 dB

• Many, relatively quiet events today 

would also result in DNL 65 dB

• However, noise experience would 

be very different
Federal Aviation

Administration

Precision Navigation

• Precision navigation is being 

implemented to increase the 

safety and efficiency of the NAS.

• It also leads to a reduction in the 

overall number of people exposed 

to noise from aircraft operations.

• However, the implementation of 

precision aircraft navigation over 

the last few years has contributed 

to the increased airport 

community concerns regarding 

noise.

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Image Source: Massport
Federal Aviation

Administration

Today’s Situation

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Old Perspective:

"If you don't like airport noise, 

then don't live near an airport." 

- Anonymous blogger in response to 

Washington Post editorial on aircraft noise

New Perspective:

People from well outside the 

DNL 65 contour are expressing 

concerns today.

65dB

Each marker represents a unique complaint address

Arrivals in Green

Departures in Red

Graphic compiled by J. Hansman et al. (MIT) using complaint data from Massport

complaint system and noise contours from the Boston-Logan International Airport 

2015 Environmental Data Report 

(http://www.massport.com/media/2274/2015_edr_compiled_final_version.pdf)
Federal Aviation

Administration

Current Noise Challenge

• Interest by the Public and Congress in re-evaluating NEPA 

Significance Levels

• Interest to accelerate reintroduction of civil supersonic 

flight

• Expansion of UAS use

• Helicopter noise concerns

• Public interest in noise associated with new projects 

• Public interest in reducing existing noise 

• Interest in mitigation and abatement

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Federal Aviation

Administration

Addressing the Aircraft Noise Challenge

• Understanding Impact of Noise

– Noise impacts: annoyance, sleep, health and children’s learning

– Aircraft Noise Modeling

– Sonic boom / puff acceptability

– Public reaction to UAS noise

– Helicopter noise impacts

• Outreach

– Increase public understanding

– Community outreach

• Mitigation

– Land use planning

– Vehicle operations

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Federal Aviation

Administration

Research Areas on Noise Impacts

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Community Annoyance (HMMH / Westat)

• Objective: Develop an updated and nationally representative dose-response 

curve of civil aircraft noise exposure and community annoyance. Query individuals 

experiencing a wide range of noise exposure near airports with variations in 

aircraft operations using an identical methodology.

• Status and Timeline: Mail survey results and a draft report are in process of being 

reviewed by FAA in coordination with Department of Transportation and other 

federal agencies. Once final, report will be made available to the public. Analysis of 

phone survey results is ongoing – likely will take a year to complete.

Children’s Learning (ACRP 02-26 and 02-47)

• Objective: Understand potential effects of aviation noise exposure on learning in 

children through test scores, classroom observations, and teacher questionnaires. 

• Results: ACRP 02-26 study showed a small but statistically significant correlation 

exists between noise exposure and student test scores. ACRP 02-47 teacher 

survey suggests that even moderate levels of aircraft noise exposure may impact 

children’s learning experiences; however, there were no observed aircraft noise 

related distractions on any day of the study period. 

• Status and Timeline: ACRP Studies are complete. Exploring next steps.

More Information: 

• ACRP 02-26: Assessing Aircraft Noise Conditions Affecting Student Learning

http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=2797

• ACRP 02-47: Assessing Aircraft Noise Conditions Affecting Student Achievement--Case Studies

http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=3693
Federal Aviation

Administration

Research Areas on Noise Impacts

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Sleep Disturbance (ASCENT Project 17)

• Objective: Develop and use an inexpensive, scientifically sound methodology to 

obtain objective measures of sleep disturbance from aircraft noise. Use 

methodology to develop relationship between aircraft noise exposure and sleep 

disturbance that is representative of airport communities across the U.S. 

• Status and Timeline: Conducted field studies to test different equipment viability 

in PHL. Validated in another U.S. airport. Recently began planning national sleep 

study that will require 4 to 5 years of effort.

Health Impacts (PARTNER Project 44 and ASCENT Project 3)

• Objective: Determine what, if any, correlation exists between cardiovascular 

disease and aviation noise. Using noise modeling with epidemiological studies. 

• Status and Timeline: Have expanded upon initial work PARTNER that used 

Medicare database to look at other health cohort databases. Leveraging work 

being funded by National Institutes of Health. Initial results with new cohorts 

coming out this year. Expect work to continue for a few more years. 

More Information: 

• PARTNER Project 44: http://partner.mit.edu/projects/aviation-related-noise-effects-elderly

• ASCNET Project 003: https://ascent.aero/project/noise-impact-health-research/

• ASCENT Project 017: https://ascent.aero/project/noise-exposure-response-sleep-disturbance/
Federal Aviation

Administration

Supersonics Interest within the U.S.

•Aerion / Airbus

•Lockheed Martin

•Boeing

•Boom Technology

•NASA 

QueSST

•Gulfstream

•Spike Aerospace

• Low-Boom Demo

• Mach 1.4, 25k MRW

• Lockheed design

• Funded through PDR

• FF 1Q2021 

• 12-18 pax 

• Low-Boom SBJ

• 6,200 nm

• Mach 1.6, 115k MRW

•> 2023 EIS

• 8-12 pax 

• 4,750 nm

• Mach 1.4, 120k MRW

•> 2023 EIS

• 80 pax Low-Boom Airliner

• 5,000 nm @ Mach 1.7

•> 2025 EIS

• 55 pax Airliner

• 4,000 nm @ Mach 2.2

•> 2026 EIS

• 35-70 pax 

• Low-Boom Airliner

• 4,000 nm @ Mach 1.6-1.8

• 8-12 pax Low-Boom QSJ

•> 4,000 nm

• Mach 1.8, 100k MRW

•> 2030 EIS

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Federal Aviation

Administration

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Supersonics Research

• Reconsider ban on operations over Mach 1 in the US

– Heavy reliance on NASA Research for identification of community 

response to sonic boom for public acceptance

• En route sonic boom standard 

– ASCENT Project 41 supporting develop of certification procedures & 

technology limits for supersonic airplanes 

• Mach Cut-off operability desired by some manufacturers

– ASCENT Project 42 examining feasibility of Mach Cut-off concept 

• US subsonic landing and take-off noise standards

– Part 36 noise standards are not applicable to supersonic aircraft 

other than the Concorde.*

• Modeling efforts (ASCENT Project 10) 

– Details provided in Emissions briefing

*https://www.faa.gov/about/office_org/headquarters_offices/agc/practice_areas/regulations/int

erpretations/data/interps/2018/Executive%20Director-AEE-1%20-

%20(2018)%20Legal%20Interpretation.pdf
Federal Aviation

Administration

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UAS Noise Research

• Certification

– Exempted in certain situations (Section 333 and Part 107)

– Measurement of UAS of multiple propulsions and weights is 

happening, but we need more noise data

– Laying ground work to develop certification framework for all UAS –

examining potential for it to be risk-based

– Examining alternative measurement methods for certification 

including measurement setups, flight regime, metric, etc. - current 

standards do not work with all UAS types

– Conducting subject psychoacoustic tests regarding the annoyance 

generated by small UAS noise

• National Environmental Policy Act (NEPA)

– Examining modeling needs

– Determining how to gather necessary information to satisfy noise 

analysis for NEPA
Federal Aviation

Administration

• Understanding Impacts

– Building off ACRP and internal study to conduct a larger study to 

understand the relationship between helicopter noise and annoyance

• Noise Abatement Procedures

– Develop noise abatement procedures for a variety (classes) of 

helicopters which will have a positive impact on the community

– PSU has developed a physics based model that currently has the 

capability to predict steady state and turning rotorcraft operations 

(ASCENT 38)

– Future work will involve additional modeling and validation

– Additional details provided in Operations Briefing tomorrow

• IFly Neighborly / Fly Quiet

– Outreach and communication programs for operators

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Helicopter Noise Research
Federal Aviation

Administration

Noise Webpage

• Want new and innovative ways to engage public

• Goal is consistent messaging regarding aircraft noise 

across agency

• Initial focus will be on basic information regarding noise 

and FAA noise policy

• Phase I content is complete

– Fundamentals of noise and sound

– Community response to noise

– FAA history of noise

• Phase II will focus on noise survey results

• Have been funding NoiseQuest website (with PSU) for 

many years, but are not sure about its utility. 

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Federal Aviation

Administration

Noise Complaint Initiative (NCI)

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• More efficiently and 

effectively address 

noise complaints in a 

manner that is both 

responsive to the 

public and applies best 

use of FAA resources

• Testing in Eastern Service Area is on-going

• AEE roll-out of NCI internal process to other service areas:

– Western Service Area 27-28 February 2018 

– Central Service Area planned for April 2018

• NCI & Noise Portal eLMS course (May 2018)

• Noise Portal Roll-out internal and public (June 2018)
Federal Aviation

Administration

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Noise Level Reduction (NLR) Research

• NLR estimation and variation

– Research effort started in 2012

– NLR variation  tolerance of indoor DNL eligibility requirement

– Diverse funding venues: AEE, ATR, ACRP, and ASCENT

• Research identified gaps and findings started to be incorporated into 

FAA’s guidance updates 

• Ongoing research is necessary to further understand the difference 

between the aircraft flyover noise and loudspeaker noise testing 

(funded by ATR) 

• Research program is expected to lead to update of a new industry 

standard via SAE A-21 (a technical committee focusing on aircraft noise 

and emissions) 
Federal Aviation

Administration

Noise Modeling

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• Higher fidelity Noise Source 

Characterization

– Develop analytical techniques 

to capture airframe noise 

(ASCENT 23)

– Develop Noise Power 

Distance plus Configuration 

(NPDC) format that enables 

more accurate noise prediction 

due to aircraft configuration 

and speed changes (ASCENT 

43)

• Propagation

– Acquired multiple sets of field measurement data and started validation of 

prediction models (ASCENT 40) 

– Evaluated and validated promising models that predict the effect of mixed 

ground types and that can be integrated into AEDT (ACRP 02-52). 
Federal Aviation

Administration

Making a Difference over Last 5 Years

• AEE has a leadership role in the ICAO Committee on Aviation Environmental 

Protection, which agreed on a new noise standard for subsonic jet airplanes in 

2013. The new noise standard ensures the latest available noise reduction 

technology is incorporated into new aircraft designs starting January 1, 2018.

• Research of the impacts of aircraft noise on learning has demonstrated that 

sound insulation is effective in mitigating impacts. Continued research of aircraft 

noise impacts on learning as well as annoyance, sleep disturbance, and health is 

crucial for understanding the impacts of aircraft noise and informing FAA policy.

• Research on aircraft source noise (ASCENT Project 23) has helped inform 

operational concepts that could help reduce noise around Boston Logan airport. 

Continued research of higher fidelity aircraft noise characterization (ASCENT 

Project 43) will improve aircraft noise modeling and assist in determining benefits 

of advanced operational procedures.

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Federal Aviation

Administration

FY19 Budget Implications

• Rotorcraft noise is a growing concern

– Issues continue with Long Island North Shore, the LA Basin, 

the Grand Canyon, and Hawaii

– Lawsuit filed by Public Employees for Environmental 

Responsibility (PEER) over excessive National Park overflights

• Helicopter portfolio has blossomed in the last few 

years and the need for research will continue.

• Helicopter research will not be funded under the 

current FY19 budget.

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Federal Aviation

Administration

Summary

• Noise continues to be a concern.

• Many initiatives are underway to address noise 

from multiple aircraft types.

• Renewed interest in supersonic aircraft flight over 

land.

• Research has made a difference but there is more 

work to be done.

• Helicopter portfolio in jeopardy under current FY19 

budget scenario.

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