I have been an avid airplane spotter since the 1950's. In those days we worried about Soviet bombers coming in under the radar. It was the height of the cold war. I truly enjoy listening for and watching the incoming planes. They are not too noisy for me.

Irony: this article (and the other two anti-airport articles) were posted on the one day this year that the airplane noise will be the lowest.

Obama is visiting town, and TFRs have banned almost all flights over Palo Alto while he is here.

Roger, it is very nice that airplanes are not an issue for you. They are for many people. Is that something that you can understand?

If there are some other things that bother you, I will not come here and just object that I don't have a problem with those things (and thus imply that no one should), simply because I will understand that we may not be sensitive to the same things, you and I.

Furthermore, even if you enjoy airplanes and their noise does not "bother" you, it can still be negatively impacting your health. For instance, it could be waking you up at night without you even realizing that airplanes disrupt your sleep. Disrupted sleep is bad for your health.

At the very minimum, please try to understand that the issue is real for many of your fellow Palo Altans.

"Sky Posse member Lee Crystal said that SFO-bound flights over Palo Alto are already up 350 percent since 2001."

+1. In addition, changes in flight path -- there are many more aircraft flying over Crescent Park, for example, than, say, 10 years ago -- and changes in the elevation -- the aircraft are, at times, flying quite low over our part of Palo Alto -- have had an appreciable impact on noise at ground level. [Note: I don't wish to diminish the impact elsewhere; I only have day-to-day experience in Crescent Park]

Pegasus. STOP stepping on the rights of others to express their opinion. Give your opinion, but do not attack others for theirs.

We've been looking at ambient noise issues in Palo Alto for the last several months and recently published an independent study on the topic. Would love to be involved in tri-city proposal to measure airplane noise levels. Web Link

And OPalo Alto persistently will not study the effects of leaded jet fuel being sprayed on residential areas. If they did, they would have to shut down the Palo Alto airport, which they would never dare do.

Kudos to the City for looking into a real quality of life issue. The late-night flights are the biggest issue (sleep disruption), and it's getting worse with the increase in planes delivering overnight packages. Train noise and night-time construction noise should also be investigated.

If I could actually hear the airplane traffic over the plethora of small engines constantly running around my house (leaf blowers, mowers, electric drills, electric saws, compressors) I'ld care more about flight paths.

*Palo Alto may blow up to $30K to study airplane noise but parking in dtpa still blows.

So how much money are we going to waste on Caltrain and airplane noise studies and action demands. Palo Alto has always had a vocal crowd, but this batch of newcomers are bring the entitlement level to a whole new level. I heard the guy interviewed on the news who said that the first few times the train went by, he ran outside to watch and thought it was cool. He said after watching the train THREE TIMES, it got old. I lived by those tracks for 20 years. YOU GET USED TO THE NOISE. I was the one who knowingly moved into a house by the train tracks, the train tracks did not pick up and relocate by my house.

Now I live right under the SFO flight path, no issue. The only thing that is occasionally annoying are the small private planes that fly low and loud.

Seriously, when is the city council going to stop appeasing the unreasonable and never ending demands of the new intolerant residents and go back to dealing with issues that really affect Palo Alto, such as the off the chart rents, losing long time small businesses, and the increased traffic?

PS: It's funny that all of these new residents of Palo Alto aren't whining about the incessant noise of construction as they tear down house after house to put expensive monstrosity on lots that are too small. People are entitled to peaceful enjoyment of their properties. That doesn't happen anymore in Palo Alto.

Construction should not be permitted on weekends. Too many people hire contractors (or handymen) who ignore the rules and start early and work late...and sometimes on Sunday. Hearing a chainsaw going all day on a Saturday only adds to stress levels.

Maybe the city council should concentrate on passing new city laws about CONSTRUCTION, enforcing the gas blower laws and other loud nuisances with which we contend daily.

Enough!

I don't think anything has ever been done about noise issues, so why don't you wait until something is actually done before saying it's enough.

So folks move under airplane flight paths and then complain about aircraft noise? That is akin to people moving near the railroad tracks and then complaining about the noise from trains. How bright is that?

@Enough! enough hit the nail right on the head:

"Seriously, when is the city council going to stop appeasing the unreasonable and never ending demands of the new intolerant residents and go back to dealing with issues that really affect Palo Alto, such as the off the chart rents, losing long time small businesses, and the increased traffic?"

Palo Alto City Council, we are waiting.

$30,000 to study plane noise. Yes we live in the flight paths of two major airports.

How much to replace the boardwalk and interpretive center at the Baylands? $0

I do not know who qualifies as a newcomer in Palo Alto but, personally, I have lived here for 25 years. When we moved here, there was no issue with commercial airplane traffic in this town. It is not like the train that has been here for over 100 years. In the early 90s, we did get some P3s from Moffett Field, and Palo Alto Airport traffic. The P3s would qualify as quaint nowadays, compared to the barrage we get from SFO and other traffic.

So, to say that we knowingly moved to a place with commercial airplane traffic and then started complaining about it is actually misinformed.

If you read the article, you will see that SFO traffic above Palo Alto has increased by 350% since 2001, which by the way is completely out of proportion with the increase in total SFO traffic. The latter has increased very little over the same period of time.

I agree that sometimes Palo Alto spends money on futile projects. This is not futile. It is a big quality of life, and even a health, issue. It also ultimately will impact our real estate values.

Jordan,

350% increase in traffic sounds about right in terms of the pressures on Palo Alto. Why would you not want to care?

Mauricio: as a point of clarification -- jet fuel contains no lead.

It is great that the Palo Alto City Council is supporting the community by being proactive about air noise. I hope they continue to taking this quality of life issue very seriously.

30 years ago, we moved to a very quiet city. When looking for homes we did reject very lovely homes because they were on the flight path of Moffet in Mountain View. We chose and paid for Palo Alto partly because of the quieter environment. Our big noise issue in the 90s was Shoreline in the evenings, not planes rumbling over head every10 minutes. Air noise is certainly affecting our quality of life and we should have the right to some peace in our homes and back yards. There is a 5:30 AM plane that flies over my roof and wakes me almost every morning. I don't think just raising the hight of the plane will make the difference. This doesn't seem fair and the thought of this noise increasing becomes a very big concern. It is far too much noise already.

Thank you to all who are staying on top of this issue.

CBS This Morning with Charlie Rose, recently did a four minute piece on the noise the FAA's new NextGen flight paths are causing in previously quiet neighborhoods around Phoenix.

"FAA's new flight paths spark noise complaints"
CBS This Morning ~ January 30, 2015 Web Link

Whoops, sorry, bad link above. The CBS piece can be found at the link below.

"FAA's new flight paths spark noise complaints"
CBS This Morning ~ January 30, 2015 Web Link

To "enough" and "good idea"

Palo Alto ordinances prohibit construction work on Sundays and holidays. Weekdays are limited 8am to 6pm, and Saturday 9am to 6pm. Homeowners are allowed more leeway when working on their homes, don't remember what the particulars are. Call PAPD non-emergency line to complain about construction noise.

Nothing to see (or hear) here folks.

Palo Alto has been on the landing path from the pacific for more than 20 years.

Those planes are quieter now than 20 years ago.

This is much like the folks who purchase homes on Park Avenue and request that the trains not blow their horns when they approach an at grade crossing. You purchased a home on the flight path...it was there for years before and will be there for years after. Deal with it.

It is totally INSANE for CPA to spend $1 on this issue and totally INSANE for CPA to spend $30k on the issue.

# Longing for Quieter Skies

I don't buy that the skies were quieter 30 years ago. Not for one single minute.

I lived in Palo Alto in 1985...we had the constant drone of airplanes leaving and landing from patrol at NAS Moffett AND NASA research aircraft as well as jets not conforming to 2015 quietness standards landing at SFO and SJC. NAS Moffett is long gone and Congress has moved all the NASA Research aircraft to SoCal.

It is a total historic fabrication that the skies were quieter in 1985.

No more real than unicorns.

Nothing to Hear,

The number don't lie. The numbers show air traffic over Palo Alto has increased 350% in the last decade, while total air traffic has only increased by 35% in that same time frame, and has only increased by 1% over the pre-911 high watermark set by air traffic prior to 911.

Aircraft are also flying much lower. Even SFO acknowledges aircraft that used to routinely fly over Palo Alto at 5,000' are now flying over Palo Alto at 4,000'. Aircraft noise at ground level doubles for every 1,000' decrease in altitude.

"Aircraft noise at ground level doubles for every 1,000' decrease in altitude."

Not that it might not be true, but... where is the study that supports that claim?

When we moved here, early 90s, the amount of heavy aircraft and jets flying into Moffatt was enormous. Some of them would put my teeth on edge, windows would rattle and conversation would have to stop. This would go on right through the night. It is much quieter here now, in my opinion.

We do hear some airliners but the most aircraft noise is helicopters. When they are circling it can go on for a long time.

I don't mind the study being done, but it sounds like a lot of money. I would like to see some money spent on improving the Baylands, our forgotten park.

Whenever Atherton and Menlo Park have their meetings protesting the aircraft noise over their towns, I always notice that for the following two weeks or so aircraft noise in South Palo Alto greatly increases as one plane after another is redirected over South Palo Alto. Then when the protests die down a little from our neighbors to the north aircraft are redirected back to their usual patterns.

So, the FAA wants to direct all aircraft over the Bay, how do they get to the Bay? Probably right over South Palo Alto. Incidentally, we have planes taking off and landing at Moffett Field and San Jose and the flights into San Carlos go up Middlefield Road. All of these flights impact south Palo Alto, I have looked up and seen some really near misses.

@everyone

Enough has this exactly right. This is worth repeating.

So how much money are we going to waste on Caltrain and airplane noise studies and action demands. Palo Alto has always had a vocal crowd, but this batch of newcomers are bring the entitlement level to a whole new level.

... when is the city council going to stop appeasing the unreasonable and never ending demands of the new intolerant residents and go back to dealing with issues that really affect Palo Alto, such as the off the chart rents, losing long time small businesses, and the increased traffic?

@Don -- "Aircraft noise at ground level doubles for every 1,000' decrease in altitude."

I questioned this contention when it was presented in earlier noise threads.
Obviously going from 1000' to 2000' will be different than 11,000' to 12,000'.
Sound energy basically follows an inverse square law with distance.
But energy is the square of amplitude, so amplitude just falls off as 1/distance.
Amplitude is the sound pressure, what's measured in decibels and what we hear.

At half the distance we'd get 4 times the energy or twice the sound pressure.
Except there's another wrinkle called Stevens' power law,
where our subjective perception of sound is found to go as pressure^0.67
so instead of being twice as loud, it sounds only 1.6 times as loud. ( 2^0.67 = 1.6 )

Turns out that to be twice as loud, the source needs to be about 3 times closer.
So the assertion of noise doubling for 1000' may hold between 500' and 1500'.

In the real world there are reflections and winds and temperature gradients and humidity that all scatter, redirect or absorb sound in various ways, particularly at larger distances, so the inverse square law is just a first approximation.

[Post removed.]

Acceptance of suffering from aircraft noise impacts seems only way. The FAA owns the skies. Many years ago a group was sucessful in getting Anna Eshoo to raise the altitude to 5000. That lasted a short while. Now the Next Gen is characterized by planes coming in at lower alitudes.

The I Ching points that shining too brightly precedes a fall. Palo Alto's over development,over crowding, housing prices, sterile atmosphere that caters to tech may eventually take it from most beautiful to least desireable.

Alan,

"...go back to dealing with issues that really affect Palo Alto, such as the off the chart rents, losing long time small businesses, and the increased traffic?"

If you had affordable housing, small businesses, and no car traffic, would you still be opposed to dealing with air traffic noise?

Thank you Sky Posse! Airport noise is a serious problem and it is indeed getting worse everywhere, not just Palo Alto. It's true that the industry has made tremendous gains in reducing noise at the source but most of these gains were made prior to 2000 (per the FAA's noise and energy office) and they have not kept pace with increases in operations, not even close. One of the most interesting developments last year was a request by 26 Members of Congress to the FAA that they change the threshold criterion used to protect communities from adverse health effects from noise from 65 dB DNL to 55 db DNL which is what the World Health Organization recommends as does almost every other organization in this country and in the world responsible for protecting public health from noise. The FAA is undertaking a 2+ year national study of the relationship between noise exposure and annoyance which they say they must complete before they can consider any changes. Unfortunately, this study, which is designed to replicate 2 earlier studies that the FAA uses to justify it's current policy, will not shed any light on the adverse health and quality of life effects of increasing aircraft noise. It really is a scary example of what now passes for science based policy in Washington. I don't understand the comments about spending $30,000. That's less than what it costs to replace the roof, windows, doors and siding in a typical house to achieve acceptable interior sound levels. And it's not as if doing that solves the noise problem. I also don't understand why anyone thinks it's unreasonable for property owners, architects, builders and land use planners to demand full disclosure of actual and projected changes in noise levels for any geographic location anywhere in the U.S. Where is this information?

The plane noise is so bad now for residents directly under the West flight path. Loud and low flying planes as low as 3,300 feet flying over my home every 3-4 minutes during peak hours of SFO arrivals and loud planes during the early morning hours of 5:30-6am and late night hours up until 1am.

Studying the Webtrak over the past 8 months has really opened my eyes to this problem and it amazes me that Palo Alto is taking the brunt of it while other cities like Atherton, Redwood City, Palo Alto Hills are pleasantly sleeping. It is time to stand up and act before NextGen is complete. The unfair distribution and the excessively low altitudes needs to stop.


Of course, the people not directly affected don't want to spend the money on gathering data. Of course, the people in Palo Alto that don't experience the noise directly over their home don't want to spend the money either. Folks are missing the point that as the planes move on the West path their altitude is getting lower and lower so that residents in Barron Park who experience the plane flying over at 5,000 feet are not hearing as much noise as North Palo Alto who has the plane flying over their home closer to 4,000 feet. Midtown gets its fair share too with the looping planes coming down from the north and heading south towards SFO. Also, folks are missing the fact that each home is built differently and has different insulation and acoustics. Some people sleep on the first floor of a 2 story house while others live upstairs closer to an older roof with no soundproofing.

It is a fact that we have become a dumping ground and if you take the time to educate yourself and watch the inbound planes to SFO on the Webtrak you may feel differently and support the action of gathering data. Whether you experience the noise or not in your location you are still breathing the pollutants and lowering the value of your cities quality of life.

Helicopters.

Stanford helicopters.

So low
and
so loud.

"Palo Alto is taking the brunt of it while other cities like Atherton, Redwood City, Palo Alto Hills are pleasantly sleeping"

How incredibly provincial - open up your eyes and the scale at which you use webtrak.

You will find that ALL of the traffic that goes over Palo Alto proceeds north over East Palo Alto, western Menlo Park and other peninsula cities to the north and does so at a lower altitude (i.e. noisier) than when it is flying over Palo Alto. That is what happens when planes are landing - they descend lower and lower as they approach the airport.

TiredResident,

Don't be so sure that one neighborhood is getting less noise than yours. The planes which come from the North (flying over Atherton at 8000 feet) charge down to 4000 over Palo Alto to make a turn, to head back up to SFO. Meantime you have the South traffic which very definitely hits the South, and the West which you mention.

And then there is the air pollution which does not neatly fall over one line.

Dear Tired,

I greatly appreciate your research and care about the deeper toxic issues such as air pollution.


Thank you,

Thoughtful

"Enough" thinks that there is no noise problem because Charleston Gardens does not get many over head flights compared to other parts of the city.

Carpenter,

"ALL" traffic crossing overland here is definitely hitting some cities harder than others and some neighborhoods harder than others. In Palo Alto's case it's several neighborhoods.

I would say what is provincial is to plan it that way, to hit the same few people with noise, and then to sit back and say that's okay.

A lot of the aircraft arriving from the Pacific and the North fly over Woodside, Portola Valley, Atherton and Menlo Park and NEVER even touch Palo Alto:

Web Link

And a lot of arrivals come down the Bay and also come vis Fremont - these also NEVER touch Palo Alto:

Web Link

If you only look at planes that fly over your house guess what you will see - just the planes that fly over your house.

Peter - yes you are so right, poor Menlo Park Oaks area and the Willows and poor East Palo alto. They have it even worse than North Palo Alto as the planes are at 3,000 feet when they hit the Menlo Intersection. I feel for all of these residents.

My hope is that Palo Alto can help all residents that are concerned about the increase in planes over their homes. According to the petition on change.org there are over 800 people concerned. I really hope that Palo Alto will study the air traffic noise and collect the data.

Peter Carpenter,

Maybe you would like to provide a study for free?

"Maybe you would like to provide a study for free?"

Personally I have studied the actual data carefully and I an confident that Palo Alto is not disproportionately impacted than many many other Bay area communities. But my opinion about these facts is just that - my opinion.

As for paying for a truly independent study - that is what we all pay taxes for.

And make sure that when the study is done that it includes not just the numerator (total aircraft ground level noise over Palo Alto) but also the denominator (total aircraft ground level noise over all Bay area communities).

Peter, it is hard to take you serious anymore. You pop up to protect Atherton every time their is a discussion about Palo Alto plane noise. Let the residents of Palo Alto have their discussion and not be influenced by your underlying motive to keep the skies over Atherton free of airplanes. Don't be fearful that if Palo Alto pursues data collection that it may in fact show the disproportionate amount of overhead air traffic we face and it may be moved over to your city, but instead join the cause to lessen plane noise for all residents of the Bay Area.

Tired - why do you so object to my presenting facts?
What are you afraid of?
What have I said that has anything to do with "protecting Atherton"?
Why should your narrow view of the problem ignore the impacts on other communities?

Peter Carpenter,

Another good idea, there should be a study to see impacts on all communities.

I'm surprised there are no studies readily available.

Here is the aircraft noise exposure map for SFO:

Web Link

It shows the contour of the CNEL (Community Noise Exposure Levels) contours for 2014 represent aircraft operations levels during 2013, the last full calendar year for which data were available when this study began.

Clearly Palo Alto is well outside the 65 db CNEL contours.

Perception of and sensitivity to noise is a very personal issue but there is ZERO data that Palo Alto is exposed to a higher measured level of aircraft noise that any other Bay area community.

Peter Carpenter,

You sound like the tobacco industry defending second hand smoke, and you make the best case for requiring an objective study.

Good idea - and you have yet to put a single fact on the table - why?

What is not objective about the SFO study and data cited above which included EVERY flight into and out of SFO in 2013?

Peter Carpenter,

What's not objective about the overall conclusion you are trying to make is, what you yourself brought up, that it "ignores the impacts on other communities."

As I posted - "there is ZERO data that Palo Alto is exposed to a higher measured level of aircraft noise that any other Bay area community."

And the SFO study proves that out to the 65 db CNEL contour. Anything less than 65 db CNEL which is the acknowledged db level for any significant impact.

Feel free to prove me wrong but remember you have to provide BOTH the numerator AND the denominator.

"The cumulative noise descriptor required for aircraft noise analyses in the State of California is the Community Noise Equivalent Level (CNEL). CNEL is used to describe cumulative noise exposure for an annual-average day of aircraft operations. The CNEL is calculated by mathematically combining the number of single events that occur during a 24-hour day with how loud the events were and what time of day they occurred.
As shown on Exhibit 4-2, CNEL includes additional sound weightings, or penalties, applied to noise events occurring after 7:00 p.m. and before 7:00 a.m., when noise is considered more intrusive. The penalized time period is further subdivided into evening (7:00 p.m. through 9:59 p.m.) and nighttime (10:00 p.m. to 6:59 a.m.). CNEL treats every evening operation as though it were three operations and every night operation as though it were ten operations. This “weighting” adds a 4.77 dB penalty during the evening hours and a 10 dB penalty during the nighttime hours.
Because of the interrelationship between the weighted number of daily noise events and the noise levels generated by the events, it is possible to have the same CNEL value for an area exposed to a few loud events as for an area exposed to many quieter events.
The CNEL metric used for this aircraft noise analysis is based on an average annual day of aircraft operations, generally derived from data for a calendar year. An annual-average day (AAD) activity profile is computed by adding all aircraft operations occurring during the course of a year and dividing the result by 365. As such, AAD does not reflect activities on any one specific day, but represents average conditions as they occur during the course of the year. The evening weighting is the only difference between CNEL and DNL. For purposes of aircraft noise analysis in the State of California, the FAA recognizes the use of CNEL, and the metric is used to assess potential significant impacts."

*******
Those are what are called FACTS.

Carpenter,

We agree there appears to be zero data.

But since you threw out your opinion, mine is that the amount of traffic has changed a lot since last year.

Your opinion may be different because you don't live here.

good idea - you are not paying attention.

"you have to provide BOTH the numerator AND the denominator." to show that Palo Alto is being disproportionately impacted.

And "If you only look at planes that fly over your house guess what you will see - just the planes that fly over your house."

You can see here
Web Link

a chart that shows one day of airplane traffic above Palo Alto and neighborhing communities. You can see that on that day Palo Alto received many more planes at a lower altitude than Atherton. It is only one day, but it is representative of what happens on most days.

Sky Posse has requested data from the SFO noise abatement office to have more comprehensive information. The office has so far refused to give it.

Pegausus just proved my point by posting a chart that explicitly states that it ONLY includes aircraft "Flight Tracks within 1.75 miles and 10,000 feet in altitude of Birch Street/California Avenue intersection."


"If you only look at planes that fly over your house guess what you will see - just the planes that fly over your house."

Doesn't anybody on this Forum understand statistics and experimental design?

Carpenter,

It's not that I'm not paying attention, what you say is nonsensical.

You are rambling about a bunch of acronyms, and equations hollering with caps, to say what?

My only point was, good idea to a study.

And that I disagree your conclusions based on what you yourself have called opinions and zero data. You keep adding "facts" in acronyms and it makes no sense.

[Portion removed.]

Please, Peter Carpenter, feel free to show us a map of one day's worth of commercial jet traffic above Atherton for any one day, complete with the number of flights. I would love to see it and compare.

PC,

I thought you already made the point to look at traffic over all the communities.

I agree with that.

Good idea NOT - the issue is not Palo Alto traffic vs Atherton traffic. Your unsupported claim is that Palo Alto is being disproportionately impacted by aircraft ground level noise more than any other Bay area community. There is ZERO data to support that claim and given the altitudes of aircraft over Palo Alto it is ludicrous to believe that it is true compared to Menlo Park (where the MENLO flight intersection is, surprisingly, located) or East Palo Alto or Redwood Shores or Foster City where the flight altitudes are lower and the ground noise levels higher.

PC,

Read back at all my posts, I don't recall making that m point, that's what you started.

My point was good idea for a study.

I do agree with you about zero data by the way, and also that more data is important so as to not ignore all the communities that are impacted.

I have no opinion about Atherton vs Palo Alto, that's your deal. Otherwise, we seem to agree.

CNEL, or Community Noise Equivalent level is not science, it is junk-science, created by, and for, the the aviation industry to help them pretend the noise they create, does not impact the community.

CNEL is an average of noise created in a 24 hour period. Loud single events are averaged with periods of near silence to get CNEL. It is very misleading to use decibels as the unit for this measure. dB/24hr would be better, but still not correct, since CNEL is a weighted average, that gives a little more weight, to noise events that happen at night.

"Aircraft noise linked to higher risk of heart disease and stroke"
Reuters ~ Oct 9, 2013 Web Link

" CNEL is a weighted average, that gives a little more weight, to noise events that happen at night."

LITTLE???

[Portion removed.]

"CNEL treats every evening operation as though it were THREE operations and every night operation as though it were TEN operations. "

PC,

LOL, from "an average of noise created in a 24 hour period"

I would agree that Ten times little is little.

"CNEL, or Community Noise Equivalent level is not science, it is junk-science"

Well here are the facts about dBA and CNEL:

"The decibel (dB) is a unit used to describe sound pressure level. When expressed in dBA, the sound has been filtered to reduce the effect of very low and very high frequency sounds, much as the human ear filters sound frequencies. Without this filtering, calculated and measured sound levels would include events that the human ear cannot hear (e.g., dog whistles and low frequency sounds, such as the groaning sounds emanating from large buildings with changes in temperature and wind). With A-weighting, calculations and sound monitoring equipment approximate the sensitivity of the human ear to sounds of different frequencies."

"The cumulative noise descriptor required for aircraft noise analyses in the State of California is the Community Noise Equivalent Level (CNEL). CNEL is used to describe cumulative noise exposure for an annual-average day of aircraft operations. The CNEL is calculated by mathematically combining the number of single events that occur during a 24-hour day with how loud the events were and what time of day they occurred."
*****
Does that "sound" like "junk-science"?

"I would agree that Ten times little is little."

So if the noise is little then why all the bother?

PC

"CNEL is used to describe cumulative noise exposure for an annual-average day of aircraft operations."

I'd say it's kind of irrelevant science for an average person's daily life.

I'm not "exposed" to noise, it either bothers me or not and I'm not a rat, so a "cumulative annual average" may sound ok for a lab, but not for real life.

The entire science of dB measurement is based on the human response to sound pressure levels and has nothing to do with lab rats.

[Portion removed.]

PC

Funny, little by your standards of 24 hour average. The "little" is the average. Your denominator.

The cumulative noise exposure is the COMBINED exposure for the aircraft noise based on the average annual DAY of operations, it is not the average impact based on combining the quiet and non-quiet periods.

"An annual-average day (AAD) activity profile is computed by adding all aircraft operations occurring during the course of a year and dividing the result by 365. As such, AAD does not reflect activities on any one specific day, but represents average conditions as they occur during the course of the year. "

PC,

Sounds like it still includes a lot of quiet periods.

Why use an average at all?

"Why use an average at all?"

The average is NOT of the noise events but of the annual flights averaged to determine the daily average number of flights in each hourly time period.

"To calculate the DNL at a specific location, the SELs at that location associated with each individual aircraft operation (landing or takeoff) are determined. Using the SEL for each noise event and applying the 10-dB penalty for nighttime operations as appropriate, a partial DNL is then calculated for each aircraft operation. The partial DNLs for each aircraft operation are added logarithmically to determine the total DNL."

Please read the direct citations which have been posted.

PC,

The measure is "not of the noise events" but of the operations, so what operations are counted, may I ask?

I thought noise measures had to do with noise monitors.

"so what operations are counted, may I ask?"

As posted above ""An annual-average day (AAD) activity profile is computed by adding all aircraft operations occurring during the course of a year and dividing the result by 365. As such, AAD does not reflect activities on any one specific day, but represents average conditions as they occur during the course of the year. "

[Portion removed.]

PC,

GIven that I seem to be your only audience, I wouldn't get too picky about my paying attention or not. Feel free to ignore me too.

I have to agree that this all sounds like made-up stuff and without relevant data, it's hard to "get it" by repeating stuff off some manual.

Maybe if you gave some real examples of a calculation with real data - or a link to something that better explains it.

"Maybe if you gave some real examples of a calculation with real data - or a link to something that better explains it."

Enjoy:

Web Link

PC

per your links

"The CNEL is calculated by
mathematically combining the number of single events that occur during a 24-hour day with how
loud the events were and what time of day they occurred."

it doesn't say single "aircraft operations" events, it says how loud events are - seems to me that they are measuring actual noise events.

I'm off to dinner now, if I don't respond it's not because I am not interested in your reply and I am curious now what exactly this is all about.

a "single event" is in fact an aircraft operation. The noise created by that single event is then determined as described here:

"The primary data required to develop noise exposure maps using INM 7.0d are:
• The existing and forecast number of aircraft operations by time of day, aircraft type, and stage length (nonstop departure trip length from the airport).
• Operational information, including runway use, location and use of flight tracks (the paths that pilots fly to arrive at and depart from the airport), departure profiles, and existing noise abatement procedures."

[Post removed.]

This effort should be amortized and folded into a City-wide effort to measure and analyze noise in our city from ALL sources and ALL places so that we have ALL-important data, which is the first line of kick back and denial by the noisemakers whenever they are complained about.

The point is, this measure estimates noise based on operations. For example, it may not do justice to the extra noise associated with descending, decelerating lengthy turns, or worn bearings,

"this measure estimates noise based on operations. For example, it may not do justice to the extra noise associated with descending, decelerating lengthy turns, or worn bearings,"

On the contrary, IF you had bothered to read the protocol which is used you would have noted that it is based on the actual flight paths which were followed.

[Portion removed.]

"C.1 Radar Flight Track Exhibits
Exhibits included in this Appendix present radar flight track data from SFO’s airport noise and operations monitoring system (ANOMS) superimposed on an aerial photograph depicting the Airport and its environs. The aircraft flight tracks depicted on the exhibits are based on ACTUAL arrival and departure operations that occurred during calendar year 2013."

[Post removed.]

I doubt much is going to change ecpect when the emissions from these planes contribute more and more to global warming so that the airports around SF are flooded.

That is probably the only thing that will slow down the FAA adding more and more planes. They have likely poured a ton of our tax payer monies into Next Gen so not likely to change it.

[Post removed.]

Resident, I agree.

Peter-Please consider that people need a place to work through an extremely challening and difficult issue. We need a safe place to share experiences.

[Post removed.]

"Peter-Please consider that people need a place to work through an extremely challening and difficult issue."

I understand but does that mean you need a fact free zone to do this?

The Terms of Use state "Please be respectful and truthful in your postings so Town Square will continue to be a thoughtful gathering place for sharing community information and opinion."

If someone posts something which is factually wrong does it threaten your view of the Forum process to have the correct facts provided?

[Post removed due to same poster using multiple names]

True

Facts:
Web Link

Web Link

Web Link

Web Link

Discussion of airplane noise never fails to embrace heated discussion.

Many planes that come overnight are associated with Fed-Ex, USPS, other mail freight / AMAZON and the dread TAA. These planes are not listed on the SFO Arrivals - their official website because they are not passenger related. However they do show up on the web sites that track planes. These are freight planes that are very old and the pilots are not in the same union as the United / Delta, etc. passenger jets.

This likens to herds of buffalo, or herds of goats, or herds of sheep - all making different noise and demands on the environment as they travel through.

Since the freight planes seem to operate with a different set of requirements regarding their aircraft - I think they should not be flying over residential areas at strange times at night.

The flight path going to / from LA - if on Southwest - typically is over under populated areas of CA - look down - is over San Andreas fault - rolling land with all type irregularities - under populated - then proceeds over agricultural land as you near San Jose. The overnight planes should be coming up the central section of CA and transition up over the bay - starting at the bottom of the bay. Since there is not a lot of air traffic overnight then they are not competing for air space.

San Jose does not encourage air traffic overnight but that may change - that place is in trouble - no passengers - no planes. This disallowance of noise may be part of the problem for SFO - how traffic is channeled and directed.

Then you have a different set of problems. Planes coming in from Hawaii - 3 different island airports so three different flights. They have to manage the flights based on the number of available planes on the ground at any time - some coming from east coast. If east coast has weather cancellations and delays then the number of planes on the ground is limited. Note that Hawaii has a lot of Asian incoming - so those planes are questionable as to age.

Recent trip in Maui the flight was ticketed for a much larger, newer plane but the available plane could not carry as many people. Everyone was re-ticked for seat assignments and a large number of people got a rebate because they would travel on a later flight. For the people that they boarded the plane was old - gasp - it actually made it over the ocean and landed. But it was an old, noisy plane. In these situations you have a large number of international passengers (Canada / Asia) and east coast that have to make connections in SFO - an international hub. If the connection cannot be made then the airlines are on the hook and have to scramble for the connections.

Any arguments about newer, less noisy planes as the rationale for lower altitudes is a wish list that does not play out in reality.

Another problem is airplane maintenance is being outsourced so where and how the plane gets some newer / replacement parts is tricky. Maintenance and logistics create a sub-set of problems the airport has to manage. If it got in the door then it can go out the door - noise or not.

Resolution in working with SFO / FAA has to account for reasonable changes that allows them to function and complete their end of the job - moving people - and accommodate the ground effects. It is a rebalancing effort.

Peter,

By your own suggestion, just looking at your house doesn't mean anything. And certainly only listing 4 separate events.

But what is your main point?

My main point is that the study is a good idea.

What is yours?

I think you want Palo Alto to stop complaining.

I will still try to understand the noise measures you have posted about but I think we have a right to complain without your interference.

"By your own suggestion, just looking at your house doesn't mean anything. And certainly only listing 4 separate events. "

I was asked a question:

"Plenty of planes fly over my home in Atherton and they are always at a lower altitude than those over Palo Alto."

True or false?"

And I answered it.

[Post removed.]

[Post removed.]

[Post removed.]

Carpenter,
[Portion removed.]

My position is pretty clear, good idea to do a study.

resident 1,

Really interesting about the cargo activity, which also seems to have come up with the train noise.

[Post removed.]

[Post removed.]

@ Good Idea,

Thank you for staying on message and emphasizing that what is needed here is a good study that shows the real extent of the problem in Palo Alto and, by extension, other neighboring communities such as East Palo Alto.

If we could get the data from the airports or the FAA, that would be fantastic, but since it is apparently not available, let us go ahead with the study.

It is a quality of life and health issue for all residents, including the most vulnerable ones, our children.

The only valid study would be one that shows the aircraft sound density footprint over every Bay area community. Then and only then would we know if any particular community is being disproportionately impacted by aircraft noise.

Looking at the aircraft sound density footprint over just Palo Alto and a few other adjacent communities ( and not Redwood Shores, Foster City, Fremont,etc,) does not answer the disproportionate impact question

[Post removed.]

According to the government science and technology contractor Wyle, there is no scientific basis for the use of a weighted average (like DNL or CNEL) as a nighttime metric/standard. The research has not even been done:

"Sleep arousal is directly proportional to the sound intensity of aircraft flyover. While there have been several studies conducted to assess the effect of aircraft noise on sleep, none have produced quantitative dose-response relationships in terms of noise exposure level, DNL, and sleep disturbance. Noise-sleep disturbance relationships have (only) been developed based on single-event noise exposure"

There is also no scientific basis for the use of CNEL as a metric/standard for children:

"A review of the scientific literature indicates that there has not been a tremendous amount of research in the area of aircraft noise effects on children. The research reviewed does suggest that environments with sustained high background noise can have variable effects, including noise effects on learning and cognitive abilities, and reports of various noise-related physiological changes"

Weighed averages like CNEL are based on the Schlutz Curve, which is the noise level at which the AVERAGE adult, is HIGHLY annoyed by noise. The Schultz Curve sets the bar to low (highly annoyed), and represents too narrow of a population (average adult).

A truly scientific metric/standard would set a more reasonable standard for annoyance (moderately annoyed?), would represent a broader band of the population (99th or 95th percentile?), and would be valid for children.


"Noise Basics and the Effect of Aviation Noise on the Environment" Web Link

PC,

I think you nailed it.

From what you have posted about SFO noise maps, they only look at traffic close to SFO, and if SFO is actually impacting Freemont, why should Freemont be left out of a noise map.

As I and others have posted, this information should be readily available and why make every city re-invent the wheel. As long as the noise maps are exclusive to only the airports, it's to be expected to want to know why the racket is up 350% outside the maps.

Jetman,

Please re=post your link to "Noise Basics and the Effect of Aviation Noise on the Environment" because it's linking back to this article. I hope the study includes this type of information.

Whoops, sorry about the bad link above. The link below should work:

"Noise Basics and the Effect of Aviation Noise on the Environment" Web Link

As I have posted many times every individual's perception of and response to any particular noise and noise level is different.

However public policy can only be made on the basis of a quantifiable and measurable standard, i.e. "loud noise" cannot be regulated but noises above a measurable dB level can be regulated as they are in OSHA standards. Standards for new jets require them to have a lower dBa and hence as the fleet is replaced with new jets the average sound level per jet will decrease. At the same time if more jets are flying the average total sound generated by all jets may increase.

The airport sound maps only include the areas within the 65 dBa CNEL curve because that is the sound level that has been determined to have an adverse impact on humans. It is a matter of public policy if that standard should be changed but it is similar to most local noise
ordinances. For example the Palo Alto Noise Ordinance uses the same standard:
"Leaf Blowers.
(1) No person shall operate any leaf blower which does not bear an affixed manufacturer's label indicating the model number of the leaf blower and designating a noise level not in excess of sixty-five dBA when measured from a distance of fifty feet utilizing American National Standard Institute methodology".

Since PA is paying for and authorizing the study then PA and the people / residents who are working the problem should define the parameters of the study.

We had the manager of the PAO as well as the SFO Manager of the SFO Noise Abatement at the meeting where the study was authorized. I think those professionals as well as the presenters of the data can work together to reach some conclusions as to where we go from here. It was a very congenial meeting and all of the participants are well acquainted with each other.

I agree that whoever pays the piper should call the tune but IF you want other people to listen to your music it is important that the music incorporate their perspectives/preferences.

Atherton / San Mateo County are represented in the SFO Roundtable. Santa Clara County is not represented. It made an attempt to join but was not voted in.
So a "no" vote at the Roundtable calls for a different approach to reach out and be recognized and heard. That seems like a common sense approach.

And we have to assume that San Mateo County and the affected cities are heard on a regular basis.

Here are some interesting facts from the SFO Roundtable:

"POLICY STATEMENT
The Airport/Community Roundtable reaffirms and memorializes its longstanding policy regarding the “shifting” of aircraft-generated noise, related to aircraft operations at San Francisco International Airport, as follows: “The Airport/Community Roundtable members, as a group, when considering and taking actions to mitigate noise, will not knowingly or deliberately support, encourage, or adopt actions, rules, regulations or policies, that result in the “shifting” of aircraft noise from one community to another, when related to aircraft operations at San Francisco International Airport.” (Source: Roundtable Resolution No. 93-01)

FEDERAL PREEMPTION, RE: AIRCRAFT FLIGHT PATTERNS
The authority to regulate flight patterns of aircraft is vested exclusively in the Federal Aviation Administration (FAA). Federal law provides that:
“No state or political subdivision thereof and no interstate agency or other political agency of two or more states shall enact or enforce any law, rule, regulation, standard, or other provision having the force and effect of law, relating to rates, routes, or services of any air carrier having authority under subchapter IV of this chapter to provide air transportation.” (49 U.S.C. A. Section 1302(a)(1))."

In their Nov 2014 Noise Complaint Report there were 1,722 complaints of which 49 were from Palo Alto. In Dec 2014 there were 2,226 complaints of which 219 were from Palo Alto.

Here is the SFO Roundtable's subcommittee recommendation and the discussion of Palo Alto's request for membership:

"The subcommittee members concluded to recommend the Roundtable not take a vote on including the City of Palo Alto as a voting member of the Roundtable."5. Request from the City of Palo Alto for Roundtable Membership"

This discussion followed:

Rosanne Foust, City of Redwood City Representative, and Rich Newman, C/CAG Representative, noted they agreed with the memo in the agenda packet regarding the Palo Alto membership request subcommittee’s recommendations. Both representatives were on that subcommittee. Rich Newman then MOVED adoption of the four bullet point recommendations by the subcommittee. Dave Burrow, Town of Portola Valley Representative, noted he did not see a reason why the Roundtable would stay just within San Mateo County. Chairperson Lentz mentioned that it is financial and logistical concerns. Dave Burrow noted that the City of Palo Alto would be willing to pay membership dues. Chairperson Lentz further explained the financial implications of bringing in another city into the Roundtable’s membership. Rosanne Foust noted that changing the Roundtable’s Memorandum of Understanding (MOU) would be an issue, requiring adoption of resolutions from each existing member city to change it. Dave Burrow indicated that the Roundtable has changed the MOU before, and having more representatives on the Roundtable would give it greater influence and voice. He also noted that County boundaries are historic and arbitrary, and would be limiting influence by not allowing Palo Alto to join.

Richard Newman recollects that the original Roundtable MOU has grown within the County of San Mateo and is not intended to be a regional body that addresses noise concerns. The Regional Airport Planning Committee (RAPC) is the regional/Bay Area group for noise concerns outside of San Mateo County, and the Roundtable should express to RAPC to get active again in such concerns.

Sue Dirge, City of Pacifica Representative and Palo Alto Membership Request Subcommittee Member, noted that the memo is a summary of what was discussed by the subcommittee for the group to consider. Expanding the Roundtable’s boundaries could bring strength but can bring dilution by expanding further south. She indicated that the Roundtable should take care of outstanding issues before allowing additional members to join, and encourage RAPC to be active regarding noise, as it will benefit everyone, not just one area.

Dave Burrow surmised that noise is biggest closer to the airport, and therefore adding people farther away would dilute the Roundtable because it should focus on closer areas, and inclusion of areas further away is not consistent with that logic. Mr. Burrow asked if that was a better way of stating what the subcommittee intended to say.

Elizabeth Lewis, Town of Atherton Representative, stated that Palo Alto experiences a lot of air traffic noise from SFO operations, is very close to Menlo Park, and does not have impacts from San Jose International Airport. She expressed that their membership would not dilute the Roundtable.

Andrew Swanson, Palo Alto Airport Manager, stated that he discussed this issue with the Palo Alto mayor, who underscored that Palo Alto’s aircraft noise impacts are from SFO. He noted that the Menlo intersection is actually over Palo Alto, and not Menlo Park.

Palo Alto resident Jim Harriet indicated that Palo Alto is the convergent point for three different paths into SFO. Over 200 flights went over Palo Alto last week with readings of over 80 dB on his noise meter. Tina Nguyen, Portola Valley resident, noted she spoke with Palo Alto residents. She questioned why Palo Alto cannot be a member of the Roundtable considering Congresswoman Eshoo’s office is in Palo Alto, the existence of the agreement that aircrafts should fly at 5,000 feet above the Menlo intersection (but actually fly at 3,800 feet), and that SFO Noise Abatement Office staff attends council meetings in Palo Alto.

Bert Ganoung, SFO Airport Noise Abatement Office Manager, clarified that an altitude adjustment at the Menlo intersection is for two visual approaches only during clear weather (such as the “Tip-Toe” visual approach and the “Quiet Bridge” visual approach). The altitude for instrument approaches during non-visual conditions is 4,000 feet. Woodside resident Jim Lyons interrupted out of order in disagreement, and Chairperson Lentz called a five minute recess.

After Chairman Lentz called the meeting back to order, San Mateo County Board of Supervisor Dave Pine questioned what could be an established standard if Palo Alto was allowed to join. Richard Newman responded by noting that there was not any way to define a boundary that “didn’t strike us at the subcommittee level as being arbitrary.” Bordering on county boundary was one way, but it became impossible to allow in just the next city without subsequent cities. He noted the city of Bolinas and Tiburon wanted to join in the past, and that it was “brought back to us through historical record” that the Roundtable was intended to be a San Mateo County body, hence the recommendation.

Rosanne Foust noted the subcommittee went back to why the Roundtable was created to look at why it was formed the way it was. She noted that the Roundtable should be a partner with Palo Alto and help it form a Roundtable that can be effective in that area. She also indicated that the subcommittee wanted to find something that was amenable, and that having 20 cities amend the charter would be a minimum of 2 years. Dave Burrows responded that the MOU has been amended in the past in a short amount of time.

Sue Dirge noted that the dilution issue was having the RAPC part “as strengthening all of our positions; that it is better to have a strong voice here and a strong voice there that are in concert with each other for the same goal. That it would bring more power to Palo Alto and to who we are here.” The intent was to be proactive and to suggest that people can still participate with the Roundtable. The focus was on the Roundtable’s strength for Work Program goals, to discuss the 65 dB noise level, and have ongoing dialogs with aircraft companies and how aircrafts operate.

Elizabeth Lewis noted she understands the Roundtable being a San Mateo County body and it has grown to include more cities, but expressed that the name of the group is the “San Francisco Airport Community/Roundtable,” not say “San Mateo County Community Roundtable.” She believes that people impacted by aircraft operations from SFO should have a voice on the Roundtable, and does not see any dilution with Palo Alto joining or as an issue different from other cities in the south county.

Richard Newman discussed when the City of Atherton joined, it did not happen on the first request. He noted at the subcommittee there was some concern that cities in the north part of the county would be likely to not support a move that would dilute their position. Southern cities would want to support inclusion.

Naomi Patridge, City of Half Moon Bay Representative, indicated that Rosanne Foust’s history was correct in that the Roundtable was originally a small group that started as a regional commission that developed into the Roundtable. She further discussed the history of when the Roundtable was organized and issues with bringing stakeholders together. She also indicated that this is her last meeting and will not run for reelection for the City of Half Moon Bay city council. She expressed that taking on more issues will not help take care of existing issues that the Roundtable is attempting to address.

Richard Newman MOVED adoption of the subcommittee recommendations. Ken Ibarra, City of San Bruno Representative, encouraged Palo Alto to stay in contact with the Roundtable and voice issues at the Roundtable. Dave Burrow commented that the Roundtable does two things: In the short-term, we try to get the airlines to minimize noise and adjust routes, and in the long-term, to have larger impacts in influencing programs like OAPM, NextGen, and randomized or focused aircraft flight paths. He expressed there is strength in numbers, and with our congressional representatives and having more people will be more valuable. It was questioned if RAPC would be more comfortable having one Roundtable body instead of two to work with. The objective of reducing noise involves working with the FAA and continuing with what the Roundtable does, and this should be an objective reason to allow an additional city in to the Roundtable.

Ricardo Ortiz, City of Burlingame Representative, noted he did not understand the “dilution issue” and is not convinced that Palo Alto should be excluded. Chairperson Lentz mentioned resources as an issue and there is a finite amount of resources. Sue Dirge noted that the dilution issue point was to not take away from what the Roundtable already has, and believes having two separate groups would be more effective.

ACTION: Richard Newman MOVED to adopt the subcommittee’s recommendations. The motion was seconded by Rosanne Foust and CARRIED with nine in favor, five opposed."

Peter Carpenter,

"In Dec 2014 there were 2,226 complaints of which 219 were from Palo Alto."

This doesn't say much without context - is that similar to other communities? What are Freemont's complaints? Or Atherton's?

" is that similar to other communities? What are Freemont's complaints? Or Atherton's?"

[Portion removed.]

Web Link

Web Link

PC,

From the report you posted, 1 complaint from Atherton.

I don't see Freemont. Are the other cities in the East Bay you were concerned about here?


Complaints Number

Atherton 1
Brisbane 764
Burlingame 5
Daly City 111
Foster City 12
Hillsborough 4
Menlo Park 6
Millbrae 14
Pacifica 282
Portola Valley 535
Redwood City 4
San Bruno 8
San Carlos 1
San Francisco 86
San Mateo 2
South San Francisco 46
Woodside 1
Other Communities
Alameda 2
El Cerrito 1
Mill Valley 1
Oakland 4
Palo Alto 219
Richmond 113
San Ramon 2
Tiburon 2

Evidently the Editors are very touchy about my raising questions about why the Weekly and other posters don't do their own research. I wonder why?

Just imagine how much better informed this discussion would have been had the original article included references to the actions and data posted above.

Good Idea - In my opinion I think you will find an excellent correlation between the SFO complaint rate and the local jurisdiction's relative sense of entitlement. For example, the good folks in East Palo Alto, which gets much more ground level airplane noise than Palo Alto, were sufficiently busy doing more important things than to file a single noise complaint in Dec 2014.

@Peter -- made me look -- and found the reference -- Web Link

>> "Andrew Swanson, Palo Alto Airport Manager, stated that he discussed this issue with the Palo Alto mayor, who underscored that Palo Alto’s aircraft noise impacts are from SFO. He noted that the Menlo intersection is actually over Palo Alto, and not Menlo Park."

Must be some misunderstanding. MENLO is 37.4637N, 122.1537W, definitely over Menlo Park by about half a mile, near the intersection of Laurel and Okeefe.

Thank you Musical for verifying the exact location of the Menlo intersection.

MENLO is clearly over Menlo Park on the charts,
but I had to dig to find lat/lon -- Web Link
Maybe somewhat flakey webpage depending on browser or online status.

Experienced pilots are aware that both the TIPP TOE Visual and the Quiet Bridge Visual approaches require pilots to fly directly over the MENLO intersection. Most of the SFO arrivals from the South are given these approaches when visual flight conditions prevail. Any aircraft passing over MENLO intersection while descending to land at SFO is at a lower altitude than when that aircraft was over Palo Alto.

To Peter Carpenter:

People may be in considerable distress related to inability to sleep, health concerns, and loss of quality of life due to the aircraft increased numbers.

That does not equate to false information. [Portion removed.]

I agree that a high level noise study is needed. Perhaps you might be helpful in arranging private funding?

" I agree that a high level noise study is needed. Perhaps you might be helpful in arranging private funding?"

No thank you. I have already volunteered 18 years as a member and ten years as chairman of the Palo Alto Airport Joint Community Relations Committee. It is someone else's turn to pay their dues.

Peter Carpenter,

"In my opinion I think you will find an excellent correlation between the SFO complaint rate and the local jurisdiction's relative sense of entitlement."

PC! Brisbane would probably not want to hear that!

But you are really one busy guy ending every note with a sassy comment like how many names thoughtful has used.

I hope the Editor can see through that comment as well and add to your dozen or so "portion removed."

jetman,

Been thinking about your post about Wyle report.

You suggested

"A truly scientific metric/standard would set a more reasonable standard for annoyance (moderately annoyed?), would represent a broader band of the population (99th or 95th percentile?), and would be valid for children.

To put some teeth into this, I would add that annoyance depends on your level of expectation. Who expects 350% increase in noise? Just reading that annoyed me. Imagine hearing it.

Might be instructive here to point out that there is nothing physical about the MENLO intersection. The Woodside beacon is a real live radio transmitter installation near Skyline Blvd. MENLO is arbitrarily defined to be 7.44 nautical miles to the northeast, on the 38-degree magnetic heading to be precise. But these days everybody just gets there using GPS.

From MENLO, referred to as the initial approach fix, it is 14.5 nautical miles (NM) to the runway. Most aircraft (and pilots) are happy with a 3 degree descent rate, and that's how the instrument landing system is set up. 14.5 NM x tangent(3 degrees) = 0.760 NM = 4600 feet (where 1 NM = 6076 feet). So I kind of wonder why so many planes are crossing MENLO at altitudes several hundred feet lower. Even with the slightly shallower 2.85-degree visual glide slope, the calculation still comes to 4385 feet altitude at MENLO. Maybe somebody who flies the heavy iron could explain.

If the NextGen track could be shifted southward of MENLO, every 3 miles would buy 900 feet of altitude. Do we annoy Crescent Park at 4400 feet, or south Palo Alto at 5300 feet, or Mountain View at 6200 feet, or Sunnyvale at ...? SFO owns all the higher-altitude airspace out 30 miles, so there are no show-stoppers with traffic from other airports.

I missed part of the presentation with the PACC. Was it ever decided that we would get a noise monitor for the south PA area - maybe one at SSL, maybe another at LMC in Stanford Research Park for the upper section of the flight path. I know that Los Altos Hills gets hit as the planes enter in from the west over the hills.
I think we should ask both of those companies to support the effort and provide noise monitors. This is engineering at its best so they would get a kick out of this - as long as it was a friendly exchange with the FAA.

"SFO owns all the higher-altitude airspace out 30 miles, so there are no show-stoppers with traffic from other airports."

Actually the SFO Class B airspace abuts and is limited by both Oakland and San Jose's Class C airspace so it does not own the full 360 degrees out to 30 miles. Therefore extending the approaches to SFO's runways 29 further to the South is precluded by San Jose's Class C airspace.

[Post removed.]

@Peter -- Looks like SFO Class Bravo from 8000-10000 over SJC. As they say, your mileage may vary. Looks like a problem for departure control. I see that San Jose departing traffic does indeed fly into that airspace on their way out of the area. I assume that will be part of the study tasks, to determine how much space is realistically available between here and San Jose for SFO traffic from the west to reach the runway 28L centerline over the bay. San Jose tower is closed from midnite to 6am so they'll never know if our favorite rumbling freighters get a green light through there at 9500 feet.

@Res1 -- Noise monitors did come up at the committee hearing, but all I recall is that our promised station never materialized. I still think monitors are a red herring. Radar tracks and aircraft types are already recorded, and are sufficient to gauge the relative variation of nuisance factors over area and time. The number of noise complaints will not be affected by what the meter says, but the tracking data alone is sufficient to prove you're getting more than your share or that the burden is getting worse. Acquisition and analysis of tracking data for the previous few years was a primary objective of the proposed study contract, wasn't it? At least to develop a pre-NextGen baseline of overhead traffic as ammunition for future grievances.

Musical,

There is an approach from the north that starts at about 10,000' over Marin and then flies down the Bay, and then does a 180 u-turn over the Bay around the San Mateo Bridge to line-up for landing on runway 28 from the south.

This approach seems to do a pretty good job of avoiding populated areas with low flights.

Unfortunately the FAA banned foreign pilots from this (and all) VFR approaches after the Asiana crash at SFO. Aircraft from the north represent 20+% of flights into SFO, so I think this FAA ban is one factor contributing to the dramatic increase in flights over the Peninsula, and Palo Alto.