A lay person's overview of how the Federal Aviation Administration measures airport noise. Details why the FAA's metrics and benchmarks are outdated, and shows how the rest of the developed world approaches this problem. Document was developed in response to FAA attempts to unilaterally implement new flight paths over densely populated areas of Minneapolis. A narrated version is available on Brainshark and www.mspFairSkies.org

1. Katana Consulting
RNAV at MSP Part II:
Measuring Airport Noise
May 2013
Kevin Terrell
Katana Consulting

2. Katana Consulting
Agenda
1. Background and FAA outreach
2. The noise metric Day-Night-Level
3. Understanding alternative noise metrics
4. Applying alternative metrics at MSP
5. Summary and action plan

3. Katana Consulting
1 | Under RNAV, SW Minneapolis and Edina would have a 5x increase in
noise and number of departures, with 23% of ~580 daily departures.
27
Xerxes Ave
Penn Ave
2012 Departure
2012 Landing
SOURCE:
•www.macnoise.com/flightrac
for Tuesday, July 10th
2012 6am + 8 hours
•Runway 30L/R RNAV
departure tracks
•Katana analysis
Key road
Proposed
departure track
RMT
50th
Street
135
23%
173
30%
4
1%
3
1%
70
12% 98
17%
98
17%
# daily RNAV
flights
% of daily total
100
17%
30R
30L

4. Katana Consulting
To date
• RNAV is a national program run by the FAA and the federal government – it will
go into effect
• The key question locally is how exactly it will be implemented at MSP
• In November 2012 the MAC recommended to the FAA that they should only
implement RNAV departures to the south of the airport, but not to the northwest
• Citizen feedback the key reason the MAC made this recommendation
• However, the MAC’s recommendation was just that – a recommendation. The
FAA can in theory do whatever it wants to do
• The FAA has tested RNAV to the south of MSP, but that trial was suspended.
To our knowledge, the FAA has not tried to implement RNAV to the northwest
of MSP
• We do not know when the FAA will make any firm decision on RNAV
• We must engage early and often in an informed way if we want to influence the
outcome

5. Katana Consulting
1.1 | In early 2013 the FAA asked the MAC to provide guidance on
community outreach efforts in order to facilitate RNAV departures off 30L/R.
SOURCE: MAC

6. Katana ConsultingSOURCE: MSP 2020 Improvements Final Environmental Assessment
1. 2 | The MAC recently completed its 2020 plan, as directed by the Met
Council. It will extend the 60 dB contour further into SW Minneapolis.

7. Katana Consulting
1.3 | A recent example of community outreach raises the issue of how well
community feedback is integrated into the decision making process.
For the MSP 2020 Expansion Plan, the MAC solicited
concerns from the public until Friday, February 8th
SOURCE: Minnesota State Register

8. Katana Consulting
1.4 | For RNAV, FAA’s outreach will advise you that there is a Finding of No
Significant Impact or “FONSI” relative to a noise limit of 65 dB DNL.
SOURCE: FAA Airports Desk Reference, Chapter 17

9. Katana Consulting
1.5 | The 65 dB line the FAA uses for a FONSI extends at most about 1.5 miles
from the end of runways 30L and 30R.
Xerxes Ave
Penn Ave
50th
Street
France Ave
30R
30L

10. Katana Consulting
1.6 | Locally we use the 60 dB line to decide if the MAC must provide noise
mitigation. The FAA does not heed that community guideline for a FONSI.
Xerxes Ave
Penn Ave
50th
Street
France Ave
30R
30L

11. Katana Consulting
Agenda
1. Background and FAA outreach
2. The noise metric Day-Night-Level
3. Understanding alternative noise metrics
4. Applying alternative metrics at MSP
5. Summary and action plan

12. Katana Consulting
2 | DNL is the modeled logarithmic average of noise exposure over the
course of a year, adjusted for our extra sensitivity to nighttime noise.
SOURCE: Overview of Noise Metrics at www.hmmh.com
Ldn = 10*log10 10SEL/10
+ 10(SELi+10)/10
i=n+1
m
∑
i=1
n
∑















÷
÷− 49.4
Daytime Nighttime
+ 10 dB

13. Katana Consulting
2.1 | However, noise experts recognize that DNL as a measurement is
flawed.
SOURCE: What’s In Your DNL?, Wyle Laboratories, 2006
Limited explanation
“Reducing noise
exposure to a single
value of DNL does
not convey to the
public the extent of
the impact upon
them”
Missing factors Not representative
“A DNL contour map
does not tell
residents how many
times airplanes fly
over them, at what
time of day, what
type of airplanes, or
how those flights
may interfere with
activities, such as
sleep and watching
television”
“If the number of
aircraft noise events
above the minimum
threshold that an
individual finds
annoying increases,
then the noise
environment for that
person has
increased”

14. Katana Consulting
2.2 | DNL does not account for real world perceptions of noise.
SOURCE: Harris Miller Miller & Hanson “Basic Aircraft Terminology”

15. Katana Consulting
2.3 | The application of DNL is based on 40 year old research showing 13%
of the population is highly annoyed by 65 decibels of average noise.
SOURCE: EC Position Paper on Dose Response 2002, Katana analysis
1972
Highly
Annoyed
% of People Annoyed by Aircraft Noise
%
Average Noise Exposure (dB)

16. Katana Consulting
2.4 | Current research on plane noise indicates that a 55 dB contour line is a
more appropriate place to draw that “FONSI” line.
SOURCE: EC Position Paper on Dose Response 2002, Katana analysis
2002
Highly
Annoyed
% of People Annoyed by Aircraft Noise
%
Average Noise Exposure (dB)
1972
Highly
Annoyed

17. Katana Consulting
2.5 | Additional research indicates that average noise levels over 55 dB can
have a noticeable impact on the reading skills of schoolchildren.
SOURCE: European Environment Agency report No 11/2010

18. Katana Consulting
Agenda
1. Background and FAA outreach
2. The noise metric Day-Night-Level
3. Understanding alternative noise metrics
4. Applying alternative metrics at MSP
5. Summary and action plan

19. Katana Consulting
3 | California uses a more nuanced logarithmic measurement called CNEL
that accounts for evening noise. Lden is similar and is used in Europe.
Lden = 10*log10 10SEL/10
+ 10(SEL+ 4.8)/10
1=n+1
m
∑ 10(SELi+10)/10
i=n+1
r
∑
i=1
n
∑














÷÷− 49.4
Daytime Evening
+ 5 dB
Nighttime
+ 10 dB
CNEL @ MSP = ~ DNL + 1.5 decibels

20. Katana Consulting
3.1 | Several countries use the 55 dB CNEL contour to restrict uses due to
health concerns. All of Europe is required to show the 55 dB contour.
SOURCE: Methods of Assessment of Airport Noise, NJS Burton, London South Bank University
55 dB contour lines required 55 dB limit on noise

21. Katana Consulting
3.2 | N70 is an easy to understand measurement developed in Australia. It is
calculated using the same noise model that the FAA uses for DNL.
SOURCE: Expanding Ways to Describe and Assess Aircraft Noise, Department of Transport and Regional Services, Australia

22. Katana Consulting
3.3 | These additional noise measures are already approved by FAA.
SOURCE: FAA Airports Desk Reference, Chapter 17

23. Katana Consulting
3.4 | Summary of noise measures
DNL
Flawed,
logarithmic
measurement
+
65 dB DNL line for
noise studies is
based on 40 year old
research
CNEL, etc N70
Updated & slightly
better logarithmic
measurement
+
55 dB contour line is
required in EU and
used by some to
limit impact
A simple, linear
measurement
=
How many times a
day can I not hear
you because of a
plane?

24. Katana Consulting
Agenda
1. Background and FAA outreach
2. The noise metric Day-Night-Level
3. Understanding alternative noise metrics
4. Applying alternative metrics at MSP
5. Summary and action plan

25. Katana Consulting
4 | Recall that the FAA uses the 65 dB contour as the area to analyze for a
FONSI.
Xerxes Ave
Penn Ave
50th
Street
France Ave
SOURCE: www.macnoise.com

26. Katana Consulting
4.1 | Other countries use the 55 dB contour. Here, that extends to Penn Ave,
beyond Lake Harriet and encompasses thousands of additional people.
Xerxes Ave
Penn Ave
50th
Street
France Ave
SOURCE: MAC PBN Overview map, www.macnoise.com; Katana analysis

27. Katana Consulting
4.2 | Beyond Lake Harriet, departing flights from medium aircraft typically
exceed 70 decibels, and would be counted as part of the N70 metric.
SOURCE: www.macnoise.com
Altitude

28. Katana Consulting
4.3 | With RNAV the N70 map to the northwest of MSP would likely blanket
Minneapolis, Richfield & Edina with 100+ count tracks & the contour extends.
Xerxes Ave
Penn Ave
France Ave
27
50th
Street
2
1
N70 100+
N70 50+
Key road
Number of daily flights greater than 70 dB (N70)
SOURCE: www.macnoise.com; Katana analysis; 55 dB line is estimated based on current RMT data
55 dB DNL

29. Katana Consulting
4.4 | Arrivals would continue over the lakes, as is the case today.
Xerxes Ave
Penn Ave
France Ave
27
50th
Street
2
1
Number of daily flights greater than 70 dB (N70)
SOURCE: www.macnoise.com; Katana analysis, 55 dB line is estimated based on current RMT data
N70 100+
N70 50+
Key road
55 dB DNL
Arrival path

30. Katana Consulting
E
G
I
J
K
L
N
V
4.5 | The 55 dB CNEL contour and N70 would affect 19 more schools than the
FAA addresses today, including 1/3 of Minneapolis’ total public enrollment
U
F
M
HO
1
29
27
7
2 Local schools
A.Lake Nokomis
B.Our Lady of Peace
C.Hale Community
D.Roosevelt High
E.Windom
F.Annunciation
G.Ramsey
H.Field Community
I.Washburn High
J.Kenny
K.Anthony
L.Armatage
M.Carondelet
N.Lake Harriet Upper
O.Southwest High
P.Carondelet
Q.Lake Harriet Lower
R.Barton Open
S.Pilgrim Lutheran
T.Lake Country
U.Burroughs
V.Academy of Holy Angels
55 dB CNEL, est.
65 dB DNL
29 RMT
N70, 100+
SOURCE: MAC PBN Overview, www.macnoise.com; Katana + community analysis; 55 dB CNEL based on 2011 RMT data
8
A

31. Katana Consulting
Agenda
1. Background and FAA outreach
2. The noise metric Day-Night-Level
3. Understanding alternative noise metrics
4. Applying alternative metrics at MSP
5. Summary and action plan

32. Katana Consulting
5 | Summary
Outdated metrics
The FAA’s FONSI is
based on an outdated
metric and a 40 year
old understanding of
the impact of noise
New metrics available We just need to ask
There are more current,
more accurate and
easier to understand
ways to express
the impact of noise on
our community
This is OUR community – not the FAA’s
Those new metrics are
available to us – we just
need to demand action
from our
representatives

33. Katana Consulting
5.1 | What you can do…
With Federal Reps…
• Sen. Klobuchar
• Sen. Franken
• Rep. Ellison
• Rep. Paulsen
With Local Reps… In the Community…
• Mayor Rybak
• C. Member Quincy
• C. Member Glidden
• C. Member Hodges
• Rep. Allen
• Rep. Hornstein
• Sen. Hayden
• Sen. Dibble
• Sen. Franzen
• Attend events
• Be an Event Captain
• Connect to resources
• File noise complaints
Require the FAA to
update how it
measures noise for a
FONSI
Demand the use of
CNEL, 55 dB and N70 to
drive transparency and
accountability.
Don’t fake it – listen to
the community!
Get started now!
>>> >>> >>>

34. Katana Consulting
5.2 | Filing a noise complaint is easy
at www.macnoise.com

35. Katana Consulting
Contact:
Kevin Terrell
kevin@katanaconsulting.com
www.katanaconsulting.com
Board Member, Lynnhurst Neighborhood Association
For further information
Sign our petition and donate at www.mspFairSkies.org
Like us on Facebook at MSP Fair Skies