Notes from on-camera remarks at the City of Folsom’s 5/14/2013 City Council meeting, regarding air...
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Notes from on-camera remarks at the City of Folsom’s 5/14/2013 City Council meeting, regarding air carrier cargo approaches and noise Prepared in July,
Notes from on-camera remarks at the City of Folsoms 5/14/2013
City Council meeting, regarding air carrier cargo approaches and
noise Prepared in July, 2013 by Paul Raveling, resident of El
Dorado Hills and possibly the only person in the EDH/Folsom area
who has: Actually measured overflight noise and observed approaches
Carefully researched actual flight tracks and operating practices
Summary: The City of Folsom referred to a pile of crap from the
Sacramento County Airport System, But the metaphoric manure
spreader belongs to the City of Folsom. For contact by email:
[email protected]
Slide 2
Approaches as portrayed by the City of Folsom: Photo: A300-600
freighter, photographed off end of Mather Runway 22L, camera lens
zoomed to 200 mm. Actual Approaches over EDH & Folsom: On ILS
glide slope, over Ridgeview at ~3,755 ft MSL, 2,610 AGL, one (1)
overflight of EDH/Folsom per night, throttles slightly above flight
idle. Typical measured noise is 66 to 68 dBA. Photo: A300-600 over
Ridgeview in EDH, Camera lens at 55 mm to match human visual field
of view At rooftop level, up to hundreds of approaches all night
long, pilots Jammin their engines full speed, super-loud &
rattling rooftops
Slide 3
Who has best first-hand knowledge? Consider home locations
Ridgeview site, four homes at point of maximum noise exposure in
EDH
Slide 4
Mode = 64.5 dBA Mean = 65.9 dBA Median = 66.4 dBA Minimum =
58.0 dBA Maximum = 72.9 dBA Range usually claimed by complainers
99.1 dBA, Actual rock-band noise measured at opening Of Folsom Lake
Crossing 87.5 dBA, Actual noise of A300 Landing measured at end of
runway
Slide 5
Another view: Given 67 dBA actual noise at Ridgeview,
mathematically derived* equivalent noise levels at frequent
complainers homes are at most at these levels 67 dBA, Reference
level: Median of measurements at Ridgeview site, El Dorado Hills 54
dBA, T.M. in El Dorado Hills 52 dBA, C.C. in Folsom 51 dBA, D.C. in
Folsom 48 dBA, G.O.in Folsom 44 dBA, M.B. in El Dorado Hills 42
dBA, H.F. in Folsom 36 dBA, W.B. in Folsom 24 dBA, J.K. in Shingle
Springs Red bars: Number of complainer home locations in each
noise-level, With 2-dBA graphic resolution *Correction for spatial
dispersion: L2 = L1 20 log( S2 / S1 ) L1 & L2 refer to sound
levels in dBA S1 & S2 refer to slant distance from ground site
to aircraft 72.9 dBA, Maximum of 2008 measurements at Ridgeview
site
Slide 6
Actual Noise Levels: Measured in EDH Mathematically derived for
homes of chronic complainers in Folsom, EDH, & Shingle Springs
Depicted as annotations on an graphic originally from URS
Corporation This is the complete image. 67 dBA is the median
(typical) noise level measured at the EDH location with maximum
noise exposure. Numbers cited for complainers homes are maxima,
actual sound livels are lower. The maxima are for no energy loss in
propagation of acoustic waves through air: Lmax(site) = Lmax(ref )
20 * log( S(site) / S(ref) ) Where S refers to slant distance.
Slide 7
Actual Noise Levels, a closer view
Slide 8
Ridgeview Overflight Altitude Distribution from flight track
samples taken in 2008; altitudes MSL
Slide 9
Rate of EDH/Folsom arrival overflights in early morning (oh
dark thirty) hours on UPS busiest days at Mather
Slide 10
Rate of EDH/Folsom arrival overflights every other minute all
night long A Folsom resident claimed on camera one every other
minute all night long Two (2) per night, 11 hours apart
Slide 11
Slide 12
Issues stated on-camera, 5/14/2013 Frequency of approaches over
homes: Statement by a citizen, Mr. Bryant Approaches at low
altitudes: Statements by Mr. Starsky and Mr. Miklos High (maximum)
throttle setting: Statement by Mr. Starsky Credibility of
Sacramento County Airport System projections: Statement by Mr.
Starsky KCRA report: City of Folsom threatens to sue if noise
cannot be reduced; original statement assumed to be by the City of
Folsom KCRA report: Mather runway expansion is planned to allow
increased cargo traffic; original statement assumed to be by the
City of Folsom Ratings of these statements in this document use the
politifact.com classifications: True, Mostly True, Half True,
Mostly False, False, and Pants on Fire. Discussion of the final two
items is omitted for brevity.
Slide 13
Frequency of night approaches over homes Mr. Bryant (citizen):
[lives on Landrum Circle: 2.25 miles from the ILS approach]: It was
constant, every couple of minutes you would have a plane come in
during the night. Fact check rating, ~ 1 approach per 2 minutes
throughout night : Pants on Fire (same sense as used by
politifact.com) At present there is a maximum of one (1) air
carrier cargo overflight per night In hours after midnight. Until
route changes were made in 2012 there were two (2) per night. If
the preceding days evening arrival is counted as a night flight,
there are two (2) night overflights, separated by approximately 11
hours. If the claim is meant to cover 12 hours (half the day is
night), Mr. Bryants statement corresponds to 360 arrivals over
Folsom per night. If it is meant to cover 6 hours, such as midnight
to 6 a.m., it corresponds to 180 arrivals over Folsom per night.
The discrepancy is 358 nightly operations for the 12-hour case, 179
for the 6-hour case.
Slide 14
Altitude on Approach Mr. Starsky: These guys come in, rooftop
level, jammin their engines on full speed. Fact check rating,
rooftop level : Pants on Fire (same sense as used by
politifact.com) LocationMSLAGL Easternmost residence 3,5703,020
Westernmost residence 2,8402,510 Almost all overflights of Folsom
are on the ILS glide slope to Mather Runway 22L, altitude deviation
usually is less than 100 feet. Overflights at rooftop level NEVER
occur. Actual Folsom overflight altitudes are: The easternmost
residences (two) are on Hildebrand Circle, between Ritchie Street
and Hana Way, ~420 feet east of Empire Ranch Road. The westernmost
residence is at or near 161 Pinder Court, ~280 feet north of Iron
Point Road.
Slide 15
Altitude on Approach Mr. Miklos: We have at, you know, oh dark
thirty, coming over at 3,000 feet, 2,000 feet; basically its the
same pattern, they rattle rooftops. Mostly False: Imbalanced toward
more wrong than right; quantitatively biased The actual altitude
range is from 3,750 feet MSL to 2,840 feet MSL (east to west).
Altitude above ground level (AGL) also depends on terrain: 3,020
feet AGL to 2,510 feet AGL. If 3,000 to 2,000 was intended to
describe the glide slope, east-to-west in the critical area: -- If
referring to MSL, its numerically incorrect: Actual is 3,750 -
2,840. -- If referring to AGL, its also incorrect but much closer:
Actual is 3,020 2,510. If 3,000 to 2,000 was intended to refer to a
horizontal band in the critical area: -- If referring to MSL, 16%
of the cited range overlaps the actual range of altitudes. It omits
82% of the actual range, with the omission entirely above the cited
range. -- If referring to AGL, 49% of the cited range overlaps the
actual range of altitudes. It omits only 4% of the actual range.
Fact check rating, approach altitude 3,000 2,000 feet:
Slide 16
Throttle Setting (=> Engine Noise) Mr. Starsky: These guys
come in, rooftop level, jammin their engines on full speed. Fact
check rating, throttle setting : Pants on Fire (same sense as used
by politifact.com) Actual throttle setting is at flight idle or
slightly above for freighters glide slope over EDH and Folsom. This
can be confirmed in three ways: (1) Researching records of flight
paths which include altitude data; (2) Asking Air Transport Pilots
who fly such airliners or cargo aircraft; (3) Inferring this by
reasonably simple mathematical analysis. Part of the math is basic
physics: An aircrafts total energy is the sum of its potential
energy (proportional to altitude) and kinetic energy (proportional
to the square of speed). Until final approach, aircraft must
decrease both speed and altitude, additively decreasing total
energy. Flying at full throttle does the opposite, increasing total
energy. Another significant relation is that in gliding flight (at
zero thrust) the glide ratio is equal to the aircrafts aerodynamic
lift-to-drag ratio (L/D). This determines the glide slope angle,
the arc tangent of the reciprocal of L/D. For air carrier cargo
aircraft over Folsom and EDH, that glide slope is very slightly
steeper than the standard 3.0-degree ILS glide slope while the
aircraft is in a low-drag configuration.
Slide 17
Useful Resources for data collection partial list, page 1
Personal observations and measurements. Photographic recording can
facilitate recording, partly by means of EXIF data. I used this in
part to record SPL (Sound Pressure Level) meter readings, using a
meter with calibration certified to plus or minus 1.5 dBA. WebTrak,
http://webtrak.bksv.com/smf -- Replays recorded flight tracks from
data originally recorded by Air Traffic Control.
http://webtrak.bksv.com/smf FlightAware, http://www.flightaware.com
-- Records history of recent operations and scheduled operations
not yet completed; also displays flight tracks.
http://www.flightaware.com AirNav, http:www.airnav.com/airport/KMHR
-- Official airport information includes pulished IFR Approach
plates and statistics on annual rates of operations
http:www.airnav.com/airport/KMHR All web-based tools listed below
except WebTrak have corresponding apps for iPads and/or
iPhones.
Slide 18
Useful Resources for data collection partial list, page 2 Live
data-feed tools which facilitate direct personal observation of
overflights: Flightradar24, http://www.flightradar24.com/ Defaults
to viewing live traffic in a simulated radar display. The web
client (with awkward user interface) also has a replay mode,
iPad/iPhone dont. The web clients user interface is more awkward
than the iPad/iPhone apps. LiveATC.net,
http://www.liveatc.net/flisten.php?mount=kmhr_norcal&icao=kmhr
This URL selects a live ATC radio feed selects NORCAL Approach
Control, Expo sector. UPS arrivals from the east and from Reno are
via Expo
sector.http://www.flightradar24.com/http://www.liveatc.net/flisten.php?mount=kmhr_norcal&icao=kmhr
Google Earth, http://www.earth.google.com Especially with graphic
annotations to illustrate the standard approach route(s). On
windows, Google Earth reports ground elevations. Using
appropriate.kml files, it can be used to illustrate at least the
standard approach path in three dimensions, and to measure
horizontal distances from observers locations to the approach path.
At the date of this writing ground elevations are not available on
the corresponding iPad & iPhone apps. .kml files on
sierrafoot.org are being updated to reflect changes made by the FAA
in September 2012 to Mather ILS
approaches.http://www.earth.google.com All web-based tools listed
below have corresponding apps for iPads and/or iPhones.
Slide 19
Useful Resources for data collection partial list, page 3
Sacramento County Airport System web site,
http://www.sacramento.aero/scas/ This site includes definitive
documents and data. Access via Google earth site searches
(Site:www.sacramento.aero/scas/) are frequently the quickest way to
locate specific information. For best browsing, these sections are
recommended: -- Mather Airport (MHR):
http://www.sacramento.aero/mhr/ Also, MHR tab under Our Airports on
SCAS home page -- Environmental / Noise, with detail subsections
for Mather:
http://www.sacramento.aero/scas/environment/noise/mather_airport_mhr/
Noise-related documents and links to
datahttp://www.sacramento.aero/scas/
http://www.sacramento.aero/mhr/
http://www.sacramento.aero/scas/environment/noise/mather_airport_mhr/
These resources are web-only, no iPad or iPhone apps.