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Updated 03/17/06
Federal legislation is the foundation for all regulation of aircraft noise. The
foundation for all aircraft noise abatement is the Federal Noise Policy, issued in 1976
which has guided aircraft noise policy for almost 30 years.
Federal Noise Policy
In July of 2000 the FAA issued a revised Federal Noise
Abatement Policy 2000 - Draft 
(pdf / 334kb / 23 pages) that
essentially reiterates the 1976 Federal Noise Policy. Airport and other industry groups
have challenged the FAA to update its Noise Policy in light of today's public expectations
and technological advances. The FAA
Western Pacific Region - Air Traffic Environmental website contains further information on the regulations
guiding air traffic routing decisions and airspace issues.
Airport Noise Regulations
Regulations that prescribe what airports can and cannot do for noise abatement are
contained in F.A.R.
Part 150 & F.A.R. Part 161. Airports wishing to institute noise new noise
regulations are governed by the Airport Noise and Capacity Act of 1990 (ANCA), which
prescribes a process that must be followed. The following article describes the issues
surrounding F.A.R. Part 161 (Federal Regulations that were promulgated as a result of
ANCA) and is used with the permission of the author.
In the years since the passage of ANCA and F.A.R. Part 161, very few airports have
attempted the F.A.R. Part 161 study process and attempted to regulate Stage 2 or Stage 3
aircraft. One airport leading this effort has been Naples Airport. The City of Scottsdale closely analysed the Naples
experience to evaluate and determine if any lessons could have been applied to benefit our
community.
Aircraft Noise Emissions
Federal Aviation
Regulation Part 36
prescribes how much noise aircraft can emit during different phases of flight. Since the
1960's when jet aircraft became more common, a cornerstone of the Federal noise policy is
the reduction of aircraft noise at the source through development of quieter engines.
Aircraft are classified in different noise "Stages" 1, 2 or 3 with "Stage
1" being the noisiest and "Stage 3" being the most quiet as illustrated by Exhibit 3C -
Turbojet Aircraft Noise Footprint Comparison (pdf / 108kb / 1pg)
and
Exhibit 3B -
Propeller Aircraft Noise Footprint Comparison (pdf / 71kb / 1pg)
from the 2004 Noise Compatibility Study.
Federal law (ANCA) requires that all aircraft heavier than 75,000 pounds
(certificated gross takeoff weight) in commercial airliner or aircraft in cargo service
meet the Stage 3 noise regulations, as mandated effectively on January 1, 2000.
Unfortunately, with the phase out of the Stage 2 commercial airliners, not all aircraft
noise concerns were eliminated. Since most airlines moved to a fully Stage 3 fleet prior
to the phase-out deadline, there was little perceived noise reduction after January 1,
2000. The business jet aircraft operating at Scottsdale Airport are not required to be
phased-out or have hushkits installed because they do not exceed the effective mandated
threshold of 75,000 pounds. Additionally, in some cases, the noise emissions have
decreased, but the volume of aircraft traffic has increased. This "trade off"
often results in a public perception of increased noise impacts.
Aircraft Noise Measurement
Federal law has established the Day-Night Level (DNL) metric as the standard for
measuring aircraft noise. The DNL metric was established by the Federal Interagency Committee on Aviation Noise (FICAN) and is the method used in
the 14 CFR Part 150 Airport Noise and Land Use Compatibility Study
process to measure aircraft noise impacts.
A criticism of the Part 150 Study process is the use of the DNL metric. The DNL metric
measures average sound instead of the maximum single-event sound which typically generates
noise complaints. More information on the measurement of aircraft noise is contained in Technical Information Paper -
"The Measurement & Analysis of Sound" (pdf / 438kb /
14pages), and at the FAA Office of Environment
& Energy
website.
15000 N. Airport Drive, 2nd Floor, Scottsdale, AZ 85260
(480) 312-2321 (480) 312-8480 Fax
(Located
at Butherus Drive and North Airport Drive) see map