Council Update on Culver City Issues

The Northerly CLIFY.

From all indications, the Noise modeling the FAA performed has a significant error in regards to Culver City. CLIFY is in a different place in the official waypoint publication than it was during the noise assessment. This means the noise assessment is going to have incorrect numbers for Culver City.


Upper flight tracks from the FAA KML are on (the misplaced?) CLIFY, lower flight tracks are on (the correct?) CLIFY. White is IRNMN STAR, Red is BIGBR STAR

CLIFY is a satellite way-point used by IRNMN, CRSHR, HUULL & BIGBR STARs to replace the SMO VOR- all the new RNAVs passing over Culver City. The (declared official) SMO CLIFY is on the same latitude as SMO whereas the (misplaced?) Ocean Park CLIFY shifts the arrival paths .47 miles north. Currently conventional flights cross over SMO.

See <The Persistant CLIFY> for a more detailed analysis.

A misplaced CLIFY waypoint affects both flight paths over Culver City

A misplaced CLIFY waypoint effects both daytime IRNMN, CRSHR, HUULL(white) and late-night BIGBR(red) flight paths over Culver City. The current SADDE conventional path is in yellow. The northern red and white are the FAA’s misplaced flight paths.

The Descent over Culver City(OPD)

The new IRNMN flight track will be an Optimized Profile Descent(OPD) until it reaches DAHJR. Over Culver City the IRNMN flight tracks from CLIFY to DAHJR will be on average 228ft higher than the current flight paths.

There was a slight lowering of aircraft altitudes in 2012 after the implementation of the SADDE RNAV which ends at SMO. The new proposed IRNMN RNAV will continue past SMO and increase altitudes slightly.

Past and Proposed flight altitudes over Culver City ( West Flow)
LocationAverage 2010-11Average 2012-142012 ChangeProposed RNAV AverageChange vs 2010-11Change 2012-14
Rancho Higuera63106206-1046437126231
Carlson Park65596384-175660848224
Lindberg Park68786201-677

Currently when aircraft pass over SMO, Air Traffic Control instructs the pilots to “Descend to 2500ft”, sometimes it’s 2600ft or 4500ft- it depends on traffic and other conditions. That instruction will disappear for those Aircraft on the RNAV. They will continue on their current descent.

Proposed OPD for IRNMN

Proposed OPD for IRNMN Approach to LAX

We will be hearing less of the engine roll back of power on the west side of Culver City. The new noise mix will include more of planes at partial power, extending flaps, and some increasing of engine power as they pass over Culver City and prepare to set up for final approach after DAHJR.

30-95% will follow the new RNAV.

The Environmental Assessment is silent on how many airplanes will follow the new RNAV. A stated assumption by air traffic controllers is that only 30% of all aircraft will fly it, yet in the noise design team they make note that 90% of aircraft can fly GPS RNAV.

Southwest Airlines now flies above 7000ft over Culver City and will drop down to be one of the airlines to fly the new RNAV. Alaska Air and Jet Blue will also follow from Day One as these 3 airlines follow GPS RNAV as company policy. Delta could also be an early implementer. The potential is that 95% of the flights can, and may, follow the RNAV.

The more restrictive RNP, which which happens after DAHJR, will be followed by less planes as it requires a type of pre-certification. Also air traffic control has to approve each individual airplane request. Likely, this will be less than 30% but its not stated in the Draft EA.

Aircraft noise over the downtown neighborhoods is already concentrated due to SMO constraints. RNAV’s keep flights within a 1 mile boundary in each direction. The current spread over Culver City is 3/4 mile each direction. The current spread is likely to remain but will become more concentrated in the center due to those following the RNP. The RNP spread is 1/3 mile each direction.

RNAV_RNP over Culver City

The current flight paths over Culver City are currently within RNAV boundaries. The RNP boundaries will concentrate flights more.


The FAA’s noise analysis has errors but its value is that it can show trends. However its most important failure is that it doesn’t describe the noise effects in a way that’s understandable to the public. People hear each plane as it passes over, they don’t average noise over a 24 hour period.

Additional metrics that describe how often and when each aircraft noise exceeds a threshold of 50 or 60db would be helpful [see Supplemental noise metrics can help public understand changes]. Without supplying this type of information, the community can’t engage. Hopefully this would be a part of an EIR.

The following maps may help you contextualize the FAA’s expected noise effects better.

Change in Noise over Residences map

Total Aircraft noise over Population map

The total aircraft noise map makes an interesting demonstration: There is more aircraft noise, on average, in the southern part of Culver City where I live, than in the northern. South Culver City hears all the flights that happen over downtown- plus we hear the LOOP departure. What’s different is the qualitative nature of the sound.

Change in Noise over Residences-map

Following is the second part of the proposed changes noise mapping- How noise will change in each census block in the SoCal Metroplex. I’ve already mapped the total aircraft noise map here.

Firstly, the FAA did provide this disclaimer about the use of this data:googleearthintro
“This information is provided for informational proposes only and is not intended for use outside the Google Earth environment. Download and manipulation of this data outside Google Earth is discouraged.”

At the risk of discouragement from the FAA, here is a visual geographic representation of the supplied data- outside of the Google Earth Environment.

This map shows the winners and losers when flight paths are moved on such a large scale.

Here is the interactive and searchable map of Aircraft Noise:

Full Screen map here:

Each dot represents a census block- an area of residential population. The amount of population in each block is between 0-2000 people. Gaps in coverage indicate areas that don’t have continuous population-open space, industrial and commercial zones are not included. (I’ve released a map of noise impacts to cultural areas such as parks and open spaces earlier – available here.)
If aircraft noise was equitably distributed among the population points there would be a balance of warm colors ( the increase in noise) with cool colors ( the decrease in noise.)

Balance of Noise Impacts over Metroplex Population
# ImpactedPercentResult
3,088,07816%The same

Most of the change in noise occurs between 25dB DNL and 45 dB DNL.  A range of noise that isn’t included in the EA’s noise criteria. The FAA’s restrictive noise criteria used by the FAA allows these increases up to 9dB of sound to not be labeled “significant”.

For examples of how the DTA Change in Noise Map is being used visit SNA: Orange and Newport Beach impacts and the Sierra Club’s comments.

Total Aircraft noise over Population map

I’m still wading through the data the FAA team has given us. Some of my initial comments to the EA team were that we needed the noise data, waypoint coordinates and.. that it’d be nice to have the Google Earth flight track data. The feedback I got back then was that was asking too much. But here it is.

Some parts of the FAA data are missing elements or incomplete and there are a couple of flight track errors I’ve found. But who’s complaining! The data is here and after quite a few hours of cleaning, parsing, segmenting, combining and organizing- I’ve been able to map it. I added population data from 2010 census and the proper centroid ID numbers- otherwise it is FAA data as supplied.. I don’t have enough time for me to do a complete analysis before the new deadline on October 8th.  [EDIT: The Sierra Club NextGen comments reflect some of the analysis and are a good intro to impacts] I also don’t understand this new FAA tendency to crowdsource the EIS but I generally like this more open access.

Before the map, a pop question: Does NextGen introduce more or less Aircraft Noise to SoCal?

Balance of Noise Impacts over Metroplex Population
# ImpactedPercentResult
3,088,07816%The same

The answer: more noise. Bummer.

The following is a map of 2015 dB DNL  noise from the proposed SoCal NextGen changes. This shows the impacts over residential areas and population. Each point represents a census block, or population center. Expand map to a separate window here.

The noise measurement is DNL which doesn’t provide qualitative information on the type of noise such as intensity or number of occurrences of aircraft, but rather represents the average noise over the day. And, I must add, it maps quite nicely.

Change in Aircraft Noise mapThis map goes hand-in-hand with my SoCal NextGen Changes in Noise map. Use of these two together will allow you to focus on new impacts vs existing conditions.

Real-world disclaimer: This doesn’t map all of the noise from airplane traffic, only those flight paths and operations that are related to the NextGen project at the major Class B & C Airspace airports plus Santa Monica. Flights between airports, and to/from the smaller airports, those in Class D and E Airspace are not in the scope of the noise analysis. No helicopters or banner towing biplanes are in this analysis.

For map fanatics this is in Cartodb with 175731 lines of data. The cloropleth mapping uses a modified Jenks to define a whole lot of buckets with symmetrically weighted breaks where the most data is. Source is FAA SoCal EA and US Census Department 2010 population data.

You may link to or embed this map using the code below according to the Creative Commons Attribution-ShareAlike 4.0 International License (just mention this website.):

<iframe src="" width="100%" height="580" frameborder="0" allowfullscreen="allowfullscreen"></iframe>

Additional 30 day extension granted

The Federal Aviation Administration (FAA) is extending the public comment period for the Draft Environmental Assessment (EA) of the Southern California Metroplex project by an additional 30 days. The comment period will now run until midnight on October 8.

The latest extension allows for a full 120 days of comment on the proposed project. The FAA previously extended the comment period by 60 days in July.

The agency also has installed new features on the project website that allow people to look up current and projected flight tracks, as well as current and modeled noise levels, on a block-by-block basis using Google Earth. Additionally, the website now includes visual depictions of noise corridors and more information about all of the proposed procedures, including the latitudes and longitudes of all waypoints. This information is available under “Supplemental Materials” on the project website –

Specific feedback on Aircraft Activity Assumptions

Below are some comments and specific feedback on the assumptions about the mix of airplanes used in modeling the noise data. Comments are specific to LAX aircraft aggregation and is also intended to be applicable as a general comment to other airports.

Segmentation of Night time operations are not represented

1.) During daytime the LAX airport operates in a predominately West-flow orientation where aircraft land on the East side and depart on the West. The EA assumes nightime as 10pm -6:30am. At LAX, nighttime operations consists of 2 operating modes:

  • From 10pm to midnight the airport continues its West-flow operations.
  • From midnight to 6:30am, the airport operates in an Over-Ocean mode where aircraft take off and land from the West side.

This results in a segmentation of the nighttime operations, as well as a switch in origin, carriers, fleet mix and possibly category that fly over the areas parallel to the airport during this late-night. This segmentation should be reflected in the modeling.

Each STAR/SID has a unique mix of  aircraft

2.) Each STAR and SID route has a different mix of aircraft which use it. The noise analysis only identifies aircraft on a per airport basis, not per route. This will result in inaccurate results. LAX airport has 3 significant STARs, which are used disproportionately by different carriers- each carrier uses a specific fleet mix of aircraft.

For instance the SADDE STAR, which collects aircraft from the Pacific Ocean and north, has Quantas, Korean, All Nippon Airways, Air China, CargoLux, China Southern, Nippon Cargo, Polar Air Cargo. These don’t use any other STAR and tend to be heavier planes. The HUULL STAR was created specifically to carry heavy planes from the Pacific.

To be accurate, the Noise model need to represent the appropriate aircraft that fly each of the airport’s major STARs and SIDs.

Normalization needs support

3.) The researchers used dataset normalization of aircraft. This is done when complete information is missing in this case data on arrivals did not equal departures for some reason. The airport is a closed system so Arrivals and departures should naturally balanced at 50% each. Aircraft should be tracked in/out to make normalization unnecessary. In order to ensure that the amount of missing data isn’t statistically significant the amount of normalization needs to be stated.  In addition normalization doesn’t take into account the following conditions:

  1. Due to the LAX airport daily change in operations direction it doesn’t mean that in/out are balanced between the daytime and nightime operation modes. ( see previous comment)
  2. Some aircraft operate on legs where their destination is different than their origin. This results in a difference in direction that may weight one side of the airport to have a different fleet characteristics.

Normalization can’t be arbitrary and aircraft must be tracked to represent actual airport conditions.

Fleet mix assumptions do not accommodate evolution/change over time

4.) From the EA’s NTR: “It was assumed that the percentages of 2015 and 2020 itinerant IFR AAD operations occurring during daytime and nighttime hours by aircraft category and type of operation would remain constant for each Study Airport from 2013 to 2015 and 2020.” This doesn’t allow for obsolescence and introduction of new aircraft, or growth of fleet to larger aircraft. The modeling of the 2015 flight tracks will already be inaccurate due to using the 2012-2014 fleet mix, the modeling of 2020 noise will exaggerate this inaccuracy. 2020 should use a modified fleet mix that incorporates air fleets planned aircraft changes.

Specific Comments about RNAV and the Socal Draft EA

Specific Comments about RNAV Implementation and the Socal Metroplex Draft Environmental Assessment.

The central community issue with the FAA’s implementation of RNAV flight paths is they take wide dispersed flow of aircraft paths and focus them into a concentration of flights around a centerline.

The modeling needs to accurately reflect the anticipated noise impacts from the proposed changes and communicate them to the public.

Instead there is confusion about the results, a lack of clarity of the changes, and aside from some specific points on specific flight paths being lowered or moved, a general forfeiture of understanding and belief. This is counter to the type of clarity a project needs to move forward.

The general questions I have are:

1.) What is the FAA doing differently to prevent the increased and concentrated ground noise, annoyance and complaints that occurred with RNAV deployment at other airports and communities such as Pheonix, Palo Alto, Queens, Charlotte, Chicago, Minneapolis and Boston, and will the implementation here have the same problems?

  • For all operations, below 10,000 ft, will the the design team keep established elevations and/or raise them higher?
  • Are areas of existing noise going to get any relief?
  • Will any movements of flight paths be sensitive to residents and not just be a shifting from one community to another?
  • How does the FAA plan to mitigate the noise from a steady and repetitive stream of flights that will be created by narrowed RNAV corridors? And why is this missing from the EA?
  • What are the NextGen’s priorities between air traffic flexibility, efficiency and a populations annoyance level?

Despite the efforts of the EA it seems difficult to accurately gauge the noise impacts without additional metrics, study and data. An attitude of “we won’t know until it’s implemented” demonstrates the limitations of the draft Environmental Assessment. The concerns of communication and clarity will be better addressed by a more robust EIS.

In the event an EIS is not performed:

2.)  Can additional feedback periods be planned for the next iteration of an EA ( if not proceeding to an EIS), and immediately after implementation?

How were RNAV/RNP’s modeled?

For people to understand the changes an accurate and complete noise modeling is to be expected. At the FAA public hearings I had numerous conversations with Noise Analysts about RNAVs. The first technical question I wanted answered was:

3.)”How was the flight track data modeled to conform to RNAV/RNP expectations?”

Surely the FAA has learned from its mistakes. They must have stacks of statistical equations and studies of existing RNAV usage to help predict distribution and  and modify future planning.

The answer I received: “The noise analysts took existing flight tracks and centered them over the new waypoints.”


Limitations of how the EA “modeled” the RNAVs.

Another question I asked was “Did you reshape, or redistribute the flight tracks in any way to make them conform to RNAV or RNP distribution rules and lateral boundaries?”

The Answer I received was “We shaped the outside contours to fit within the expected outer boundary.” The authors of a paper documenting the procedure claimed that no reshaping was done [11] so this is an interesting point of disagreement.

4.) Can the FAA supply the correct answer to this?

Using the nominal (as-is) flight tracks may give an adequate result when one RNAV is replacing another but it will completely fall apart when the new RNAV is significantly different. In addition a more laterally restrictive RNP final approach procedure will be completely inaccurate. Dispersion modeling of new RNAV and RNP procedures through a statistical analysis of past RNAV/RNP or using a formulaic distribution model will yield a more accurate result of expectations and future traffic.

The expected outcome of RNAV implementation

The expected outcome of RNAV implementation (Phoenix RNAV changes)

The expectation of RNAV and RNP is a concentration of flights along the flight path centerline. This increase in operations along a fixed path would result in an increase in noise effects, Specifically recognized by metrics such as N60 or N70 (number of airplane related noise events above 60 or 70dB) and represented by DNL, along the centerline, and a decrease at the outer boundary.

Number of Aircraft flying the RNAV

It is assumed that not all aircraft will fly the RNAV. Statement of the exact number of RNAV users is required for noise modeling and needs to be explicit in the EA. An FAA ATC rep shared at the LAX public meeting that only 30% of the aircraft are expected to fly the RNAV.  This number is based off the number of current flights that currently use IFR.

The Study team estimated that 90% of LAX aircraft are RNAV capable. To fly RNP the planes FMC needs to be RNP-0.3 capable and the fleets must train the operators, and be approved. Industry source suggest the RNAV capable aircraft is 95%.

Culver City is in the North downwind leg of LAX. The IFR plates for the SADDE SIX STAR that routes arrivals into the downwind leg has this to say about how to fly over Culver City:
..From over SADDE INT via SMO R-261 to SMO VOR/DME, then via SMO R-068 to SMO 9 DME for Runways 24 and 25. From SMO 9 DME expect vector to final approach course for Los Angeles Intl Airport.” The ATC issue these instructions: “..cross Santa Monica VOR at 7000, descend and maintain at 2500.

The low number of aircraft following IFR is probably due to it not offering much benefit while under clear skies. GPS RNAV is very different than current IFR and linking them will not yield an accurate estimate. Even without the NextGen Program the flying public has been wanting better integration of satellite navigation.

5.) The percentage of planes expected to utilize RNAV and RNP is not explicitly stated in the EA and requires arguments to support why this number is chosen. .

6.) What values for frequency of RNAV vs conventional flight tracks were used in the noise modeling? The noise analysis assumptions needs to be verified and explicitly stated so as not to be arbitrary.

What are possible RNAV mitigations

7.) Is it possible to deploy Satellite navigation efficiencies without the concentration of  disadvantages of the current NextGen deployment. With procedures that use appropriate distances and altitudes to minimize noise impact?

8.) How far away is the technology, or is it possible now, to deploy multiple dispersed flight paths within an RNAV corridor that will more equitably distribute noise over a larger area?

9.) What new mitigation strategies will you be deploying to communities burdened with RNAV overflights? Will you fold them into noise mitigation programs reserved for 65DB DNL, will you supplement funding by RNAV users, the NextGen Program or other source?

10.) DNL doesn’t seem adequate to describe the situation of a concentrated flight paths effects. Can a supplemental metric such as N60 or N70 be used to describe this to the public?

[1]“Super Density Operations Airspace Modeling for the Southern California Metroplex, AIAA Modeling and Simulation Technologies Conference,, Sebastian D. Timar, 2011”
*A nautical mile represents a minute of arc or 160th of a degree along a meridian or great circle. Its continued use makes chart reading easier as grid spacing is one minute of latitude.

The Persistent CLIFY

This weekend I sat down with the newly released KML and way-point data from the FAA. The new authoritative “TARGET” way-point data allowed me to confirm my coordinates and there were no surprises there. Once I loaded up the new flight track KML on top of my authenticated flight tracks I got a bit of a surprise:


Upper flight tracks from the FAA KML are on Clover Park CLIFY, lower flight tracks are on SMO CLIFY. White is IRNMN STAR, Red is BIGBR STAR

When we first met CLIFY in June it was crossing a tree in Santa Monica’s Clover Park, but since July 1st CLIFY has been closely aligned with the SMO radio beacon [ see CLIFY got Moved ]. Somehow, withe the KML release it’s back in Clover Park again. I assume that the coordinates released in the <8/25>TARGETS Distribution package last week are authoritative- they do match the “corrected” coordinates given out July 1st. Browsing around the released Google Earth KML I noticed other anomalies in the KML.
–UPDATE*1 the 9/22/15 TARGETS package has moved CLIFY back over Clover Park. The KML was right. This EA comment was written before the 9/22 adjustment. Some of this discussion is only relevant for the 8/25 —

–UPDATE*2 The 9/2/16 Final EA moves CLIFY back next to the SMO VOR.
But why is this CLIFY position persistent and how far back does it go?

CLIFY is a satellite way-point used by IRNMN, CRSHR, HUULL & BIGBR STARs to replace the SMO VOR. The SMO CLIFY is on the same latitude as SMO whereas the Clover Park CLIFY shifts the arrival paths .47 miles north. Currently conventional flights cross over SMO.

A brief timeline:

  • June 18th, 2015- Initial way-points from presentation boards: 34° 1’1.35″N 118°27’23.94″W
  • July 1st, 2015- Presentation board “correction”: 34° 0’36.64″N 118°27’25.58″W
  • August 25th, 2015- TARGET Distribution package: 34° 0’36.64″N 118°27’25.58″W
  • September 3rd, 2015-Google Earth KML Data:  34° 1’1.35″N 118°27’23.94″W
  • *–September 22nd, 2015- TARGET Distribution package: 34° 1’1.35″N 118°27’23.94″W *UPDATE–
  • *–September 2nd, 2016- Final EA: 34° 0’36.64″N 118°27’25.58″W *UPDATE–

Prior to the June 18th presentation board releases the only comparative mapping of the flight paths was in the Noise Technical Report, released as part of the EA. A layered pdf shows  current conditions and proposed changes. Fortunately, I had already disassembled the pdf so I can readily isolate and identify the flight tracks. The images below show the vector outlines of the flight paths, the green and orange color are the superimposed flight tracks.

Comparing current to proposed demonstrates a shift to the north of the flight tracks at SMO. That flight tracks are at 2 different latitudes. Supporting analysis of the density of the paths relative to I-10 support that the Clover Park CLIFY was being used while the noise analysis was being created.

Was the noise analysis performed with the Clover Park CLIFY?

There is enough separation between the daytime flight paths to compare noise effects. The (SMO)IRNMN enters Culver City at Overland and Venice and is .21 nm north of the Conventional SADDE STAR and .2 nm south of the (CP)IRNMN.

A misplaced CLIFY waypoint affects both flight paths over Culver City

A moved CLIFY waypoint effects both daytime IRNMN, CRSHR, HUULL(white) and late-night BIGBR(red) flight paths over Culver City. The current SADDE conventional path is in yellow.

The SADDE/IRNMN flight tracks from CLIFY to DAHJR are effectively the same altitude and descent angle under IFR so one would expect the same noise impacts. I loaded the newly released US Census Block Population Centroids Noise Grid data. (Hooray and thanks FAA.)

The expected behavior should be a decrease in noise south of and along SADDE, an increase along the new SMO IRNMN, and an increase along the Clover Park(CP) IRNMN by a small amount as it picks up additional flights. Increases .2 nm North of the OP IRNMN should be less than the either of the IRNMNs.

[Edit: it may be easier to use my new Change in Noise map than this table to trace the dB DNL change]

Census Centroid dB
1.8 nm44.2-.444.1-0.344.1-0.243.8-
2.5 nm44.5-.444.3-0.344.1-0.243.8043.30.1
2.9 nm44.5-.444.4-0.344.2-0.143.8043.40.2
3.2 nm44.6-.544.5-0.444.3-0.244.1043.80.1
3.6 nm44.8-.544.7*-0.3*44.4-0.144.2043.80.2
DAHJR (5nm)45.2-.645.1-0.444.

Immediately the CP IRNMN is behaving oddly with a net change of “0”. This is not an appropriate response to being within the outer boundary of a new flight path- especially when considering the north path’s noise is increasing at a faster rate. SADDE and South of SADDE are decreasing- and they even seem to be decreasing as if they are moving outside the RNAV outer boundary. From these result it appears that the noise modeling flight track may be going over the CP IRNMN.

An alternate interpretation is that an erroneous Optimized Profile Descent(OPD) calculation of -.1 or more is being added. It is expected an OPD will decrease the noise from a aircraft with a high throttle setting but it hasn’t been proven that high throttle planes is dominat noise producer for this descent. Correcting that assumption lets the SMO IRNMN fall in line but it still leaves the CP IRNMN suspect and the North requiring a further examination.


The noise modeling under the IRNMN flight path is suspect.

  • Was CLIFY misplaced in Clover Park during the noise analysis?
  • Is an OPD benefit being misapplied?
  • Is the RNAV -> RNP narrowing being properly represented?

The noise analysis around the IRNMN/CRSHR/HUULL RNAV requires further investigation. BIGBR also uses CLIFY and should be investigated as well particularly since it has been lowered 1000ft at CLIFY.

The KML data does not reflect final waypoints but it gives an interesting glimpse in the earlier stages of the project. I believe we need to have an auditor look at the noise analysis, or this should proceed to an EIS as the integrity of the analysis is in question.

–These instructions were relevant 9/7 and may be different based on the 9/22 change- refer to your data package before updating–
To replace CLIFY in your dataset with the “official” TARGET coordinates search the KML for all instances of -118.4566494689281,34.01704041074508 and replace with -118.4571055555556,34.01017777777778. There will be 41 replacements. This will only patch the Proposed Action Procedure Routes. Flight tracks and Corridors will still be incorrect.
Other errors:
1.) LAX BIGBR STAR has at least 5 extra waypoints Between CLIFY and TOMYS over Baldwin Hills that should be deleted.
2.) KLIPR (in LAX ORKA SID) should be -118.4323611,33.9329444 not -118.4131911521656,33.95149537535652

Waypoints are available in the TARGETS Distribution Package from the EA website. Google Earth stores them as -Longitude(Deg),Latitude(Deg).

LAX Roundtables review and comment of Metroplex Procedures

At the July meeting of the LAX / Community Noise Roundtable Boardmember Steve Alverson summarized the LAX specific changes in the draft Environmental Assessment.  He listed some of the proposed changes to arrival and departure procedures and the extent to which Roundtable noise abatement recommendations were incorporated into the proposed procedures.

It’s worth viewing, particularly starting at page 12- though admittedly these slides may appear cryptic as they won’t represent the oral presentation and discussion made during the presentation.

Download (PDF, 5.58MB)

The EA describes the “purpose and need” of some of the flight path changes in Section 2 and The Design Team Tech Report describes the result. What’s missing From the EA is:

  • An explanation to “why” the proposed action was determined to be the most optimal,
  • The expected impacts on the ground in metrics and population exposure to noise.

An impact analysis of each flight track change, specifically any altitude lowering or significant lateral movements over population should be within the proposal.  Environmental Assessments are considered cursory, possibly an EIR could better communicate the impacts to the community.

The Roundtable has sent their comment letter which addresses the following points in a summary fashion:

  • The Shifting and Exposing Noise to New Residential Areas
  • Aircraft Flying at Lower Altitudes
  • Concentration of Flights
  • Making adjustments to Procedures after implementation
  • Integrating the round Tables September 2012 recommendations
  • The Deconflicting of SMO & LAX Departures
  • Use of supplemental Noise Metrics
  • Insufficient information in the Draft EA

You can explore the rest of the document in this PDF:

Download (PDF, 1.59MB)

If the above doesn’t work in your browser, I’ve include the first 2 pages here and a link at the bottom:


September 2, 2015

SoCal Metroplex EA
Federal Aviation Administration
Western Service Center – Operations Support Group
1601 Lind Avenue SW

Renton, WA 98057

RE: Comments on the Draft Environmental Assessment for Southern California Metroplex Project

Dear Sir or Madam:

The Los Angeles International Airport/Community Noise Roundtable (Roundtable) is a voluntary and independent body that consists of membership from local elected officials and staff, representatives of congressional offices, members of recognized community groups, airlines, Los Angeles World Airports (LAWA), and the Federal Aviation Administration (FAA) as a non-voting member. These parties work together to identify noise issues that affect communities surrounding Los Angeles International Airport (LAX) and seek feasible solutions to reduce aircraft noise in those affected communities.

The Roundtable recognizes the FAA’s efforts to improve efficiency and enhance safety in the Southern California airspace by developing approach and departure procedures that take advantage of satellite-based navigation technology. These new satellite-based procedures are intended to enable aircraft to fly more efficient, direct routes and enhance safety through improved predictability and repeatability of procedures. The new procedures will also change where and how aircraft fly and may potentially affect the residential communities.

The FAA prepared the Draft Environmental Assessment (EA) for the SoCaI Metroplex Project to document the potential environmental effects associated with the proposed procedures and initially provided the public with 30 days to review and submit comments. After receiving a number of requests, the FAA extended the public comment period by 60 days with a new deadline of September 8, 2015. The Roundtable appreciates the FAA extending the comment period to allow the public additional time to review and provide comments regarding the potential environmental impacts of the project. Roundtable’s Concerns and Suggestions

The specific comments contained in this letter are not intended to be comprehensive, but instead are representative of the general concerns that this body has identified. The Roundtable is concerned that if the Metroplex procedures are implemented as proposed in the EA, they will result in: 1) shifting noise from one community to another; 2) exposing new residential areas to aircraft overflights; 3) lowering aircraft altitudes over certain communities; and 4) creating a concentration of flights over a narrower area when compared to the existing conditions.

Shifting and Exposing Noise to New Residential Areas

Some of the most prominent changes with the proposed procedures occur during east flow operations with the two main LAX arrival routes, used by aircraft arriving from the east, shifted north and south of their current location by 2.3 and 1.6 nautical miles, respectively, on the LAX BIGBR1 and BRUEN1 STARs. These proposed arrival procedures will cause aircraft to fly over residential areas that did not previously experience aircraft overflights. In addition, the proposed departure procedures for east flow operations will shift noise from one location to another. For example, the LAX TRTON1 SID directs aircraft to make tighter turns after departure toward the east, resulting in shifting of noise that affects the beach cities. The LAX GARDY1 SID directs aircraft heading eastbound to fly a route that will expose residential areas that do not routinely experience departures from LAX to new aircraft overflights. These proposed changes are significant enough to cause residents to notice a change in flight patterns even though east flow operations only occur about five percent of the time during the course of a year.

To help minimize noise exposure associated with these and other proposed changes that result in shifting and exposing noise to new residential areas, the Roundtable suggests that the FAA reduce the shifting of aircraft routes where possible and develop procedures that mimic current flight routes as much as possible. If modification to existing routes is required, consider routing aircraft over commercial and industrial areas instead of residential areas to avoid noise exposure to the residential neighborhoods.

Aircraft Flying at Lower Altitudes

Some of the proposed changes will cause aircraft to fly at lower altitudes over certain communities. The FAA created the CLIFY waypoint to replace the SMO VOR for the purpose of satellite navigation. Aircraft arriving to LAX normally fly over the SMO VOR at 7,000 ft. during Westerly Operations (normal daytime traffic pattern) and at 8,000 ft. during Easterly Operations (wind conditions) and Over Ocean Operations (normal nighttime pattern from midnight to 6:30 a.m.). With the proposed changes, aircraft will fly over the CLIFY waypoint at 7,000 ft. regardless of the traffic flow configuration. This will cause aircraft to fly 1,000 ft lower during Easterly Operations and Over-Ocean Operations, creating a noticeable change for this area community that is already sensitive to the high volume of air traffic descending for arrival.

Another example of aircraft flying at lower altitudes is associated with the proposed LAX LADY J departure procedure. This procedure will lower the altitude requirement for aircraft flying over Malibu. As proposed, aircraft will cross the waypoint LADYJ located in Malibu at 8,000 ft. rather than the existing CHART waypoint at 9,000 ft. Aircraft will be flying 1,000 ft. lower over Malibu and cause residents to notice a change in altitude.

The Roundtable recommends that the FAA maintain existing altitude requirements for the SMO VOR (CLIFY waypoint) and the LADYJ waypoint. Residents will indubitably notice aircraft flying at lower altitudes at these locations if the minimum altitudes are lowered by 1000 ft. The FAA can avoid this potential noise issue altogether by not lowering the altitude requirements for any procedures.


link to Roundtable Comments on Metroplex Changes


Are the Airspace changes good or bad for Culver City?

I was asked recently if the changes to the airspace are Good or Bad to Culver City. My answer, which we discussed at the last Culver City meeting about NextGen impacts, is “Yes, No, and We won’t know until its implemented”. The FAA has a summary of potential benefits for the entire airspace and Culver City’s changes would be a subset of those. The changes are not without precedent- Other communities have undergone a NextGen implementation and we can use their experience about what to expect.

A petition called “Stop the FAA NextGen Flights Over Culver City” cites many examples but doesn’t offer the full perspective of the potentially subtle issues of the FAA proposed implementation. Hopefully this can help inform people about what to comment about if they choose to sign that.

FAA Metroplex Presentation-14

From a noise perspective there are no benefits, only negatives: The proposal shifts noise around [ Noise mapping ] in the areas that have noise above 45 dB DNL and increases noise in softer areas [ Noise impacts by Population ]. We cant’ even answer whether the City of Culver City has a net gain or loss of noise (note: the FAA  released on 9/1/2015 the source data for the noise analysis – it will take time to analyze to find this result). The noise modeling itself has faulty components [ various comments ]  and the pollution conclusions are purely theoretical.

There isn’t a rigid flight path over Culver City. LAX arrivals fly over Santa Monica Airport at 7000-8000 ft. After Santa Monica the pilots are given the instruction by Air Traffic Control to “maintain heading and descend to” either “4000”, “2600”, “2500 ft”. IRNMN. CRDHR. HUULL provide a fixed, and precise flight path.

My earlier post described how the flight paths may change [  Culver City Flight Paths ] and a potential issue [ Proposed flight path undermines LAX noise Abatement efforts ] with over-ocean operations. These would be a good primer for the discussion below.

Here is just a short breakdown of Pros and Cons just for changes over Culver City:


  1. The use of RNAV and Optimized profile descent (OPD) will mean that the planes will be following a more formal descent which will reduce the range of pilot chosen descent options. Possibly there will be reduced noise causing operations such as flaps and power-downs.  On average the heights may be near the same but the range of higher and lower elevations will be slightly reduced.
  2. RNAV to the DAHJR waypoint, and RNP to the airport, will reduce the spread of airplanes farther away from the flight path- reducing noise. The spread wasn’t so wide to begin with, due to flights having to cross at SMO, so the difference won’t be as severe as when RNAV was rolled out other places. The concentration of flights are currently within 3/4 mile so narrowing into 1 /3 of a mile will only save ~ .2-.4 dB from outside the path. Other communities start with paths miles wide.
  3. It’s only going to initially effect 30-40% of the flights*. The same variance will still be happening just at a slightly smaller scale. Over time the nonconforming flights will reduce  as the fleets get replaced/upgraded and crew trained.
  4. There may/or may not be a reduction in emissions / fuel use by the shortened and  lowered BIGBR flight path. There is a potential of savings by the Optimized Profile Descent but that’s indeterminate until we see how the planes fly the OPD.
  5. When comparing against doing no changes, The FAA’s Environmental Assessment(EA) models a decrease of 0.0-0.02 dB DNL* directly under the proposed daytime flight path, and -0.4 dB DNL* decrease directly under the proposed, and lowered, late-night flight path BIGBR.


  1. It’s never a good idea for people under a distributed flight path to have the path narrowing above them via a single-path RNAV or RNP.  It’s a concentration of noise and pollution over a smaller population that runs against environmental justice. The residents of Pheonix, Boston, Santa Cruz, Palo Alto and other communities across the country attest that living under a RNAV/RNP proposed flight path is going to have significant effects on quality of life.
  2. Optimized profile descent (OPD) with a flight path dictated rate of descent doesn’t work with same efficiency for all planes. One of the claims in Palo Alto’s suit is that OPD is increasing noise as planes have to flutter power, keep partial power on or engage in more side-side drift instead of a reduced power coast-down. The FAA is betting a large part of the sound analysis results on OPD’s reducing sound above 6000ft.
  3. The DNL* metric is used more as a measurement of expected annoyance than as a real noise metric. The averaging over the day occludes the real way we hear airplane noise- one plane at a time. A metric such as N60 or N70 ( number of airplane-related noise events over 60 or 70dB ) is a far better predictor of impacts. This data has not been released by the EA. [ Supplemental noise metrics can help public understand changes ]
  4. There will be more noise from the BIGBR flight path. The midnight-6:30am over ocean flight path and eastern operation flight paths are combined into one flight path. The crossing at Santa Monica’s CLIFY has dropped from 8k to 7k. The closer movement of the immediately prior waypoint [DOWNE to TOMY] means planes will overfly Culver City between 1k-800ft less. This flight path won’t be using OPD.
  5. If the flights over downtown Culver City are going to suspend their power-downs, flap dropping and other noise making operations until out of the RNAV at the DAHJR waypoint, that same noise will happen further east at a lower altitude. It will be worse for somebody. These specific noises are not modeled separately in the analysis.
  6. The flight paths have shifted slightly northward so the noise footprint will include communities that didn’t have it bad before.
  7. Overall the Proposed action uses .33% more fuel than without it. Emissions will increase from the Proposed action as well. The amount of fuel saving/waste for the tracks over Culver City hasn’t been itemized.
  8. It’s only going to initially effect 30-40% of the flights. Overtime it may include almost all. According to the FAA study team, 90% of LAX arriving aircraft is capable of RNAV.

Planes are progressively getting larger and quieter but the emissions aren’t going away. Air traffic hasn’t returned to the pre September 11th values so an increase in traffic is to be expected.

One of the complaints against the FAA is the process. Community input wasn’t invited during the design process and the results of changes are not readily understandable. The metric used to describe noise level is DNL [ Supplemental noise metrics can help public understand changes ] which tells nothing about the loudness of each plane or how many times it flies over.

The Environmental Assessment(EA) is not intended to be a rigorous process as it is performed in lieu of an Environmental Impact Report(EIR). It’s purpose is to prove the assertion that there will be no significant impacts and a more rigorous EIR is not needed.

Proposed flight path undermines LAX Noise Abatement efforts

The proposed LAX BIGBR STAR replaces the BASSET and REDEYE conventional procedures. I am concerned about the increased noise impact that lowering the altitude 12.5% over residential areas will cause.

UPDATE 9/2/2016* The proposed LAX MDNYT STAR will replace REDEYE for Over Ocean Operations. It is unclear from the Final EA whether the new CLIFY height will be 7000-9000 ft or 8000-1000 ft. This article pertains to the Draft EA specifying a lower 7000 ft crossing.



The REDEYE procedure is a part of LAX’s Over Ocean Operations – a voluntary noise abatement runway use program in use since 1985. The REDEYE crosses SMO at 8000 ft, but the northern path of the proposed BIGBR STAR will cross the SMO equivalent CLIFY at 7000 ft.

BIGCR STAR - Proposed

BIGBR STAR – Proposed



According to the Design Team Tech Report, BIGBR will NOT be an Optimized Profile Descent(OPD) profile under 14,000 ft. The altitude lowering won’t benefit from the partial OPD mitigation.

The LAX Over Ocean Operations are deliberate noise abatement procedures that occur everyday between midnight and 6:30am.

Easterly Operations at LAX are implemented only when wind conditions require reversing the traffic flow of the airport for safety.

LAX Air Traffic Flows

There may be safety and operations flexibility reasons to propose moving the Easterly to the Over Ocean arrival path but the operations serve different purposes. There can be no reason to nullify the positive effects the Over Oceans Operations has continued to have on residents health and sleep.

Please respect the intent of the Over Ocean Operations to abate late-at-night noise in neighboring communities and return the proposed lowered flight paths to the no-action existing altitudes.