Demand Forecast for Mather Airport Air Carrier Cargo Operations

Demand Forecast
Mather Airport Air Carrier Cargo Operations

For purposes of considering noise impacts the key metric is number of approaches per day which overfly El Dorado Hills and the southeast corner of Folsom. The primary factor producing this demand is landed tonnage of cargo shipped by air carrier cargo operations.

Here is Mather's actual landed cargo tonnage'
Source: Federal Aviation Administration, published on web at http://www.faa.gov/airports_airtraffic/airports/planning_capacity/passenger_allcargo_stats/passenger/index.cfm

Year	National Rank	Landed Cargo
2006	53	514,635,360
2005	56	516,160,480
2004	59	503,226,000
2003	55	512,065,700
2002	53	548,703,150
2001	39	834,861,000
2000	31	1,096,866,900
Statistics not available prior to 2000 from FAA web site

Mather Master Plan forecasts

	Total	Over EDH	Over EDH 3:30-6:30* a.m.
Current arrivals per day, maximum observed	11	8	4
Current arrivals per day, minimum observed	1	0	0
Current arrivals per day, average	6.43	4.00	2.00
Current typical counts for days of the week with generally high activity	10	7	3
Master Plan projection for 2021, average, base range Original source citation: 10,600 operations (takeoffs + landings) per year	14.52	9.43**	4.52**
Master Plan projection for 2021, average, high range Original source citation: 15,300 operations (takeoffs + landings) per year	20.96	13.04**	6.52**
Claimed in EDH CSD Resolution 2007-28	80.38**	50	25.00**
* All early morning arrivals occur between 3:30 a.m. and 6:00 a.m. unless a flight near the end of this time range has an exceptional delay in arrival. ** Derived from average total arrivals by applying the same ratio of "approaches over EDH" and "approaches over EDH 3:30-6-30 a.m." to the SCAS forecast for average daily total arrivals or to the EDHCSD claimed rate of approaches per day.

The essential forecasts for 2021 from the Mather Master Plan are a Base Range forecast of 10,600 air carrier cargo operations per year and a high range forecast of 15,300 air carrier cargo operations per year. See table 3-7, which is copied at the end of this page with color highlighting added to call attention to these forecasts.

A point of bias in the EDHCSD resolution is that it refers to the high range forecast and ignores the base range forecast.
A point of error in the EDHCSD resolution is that it indicates that 15,000 arrivals per year produces 50 air carrier cargo overflights of El Dorado Hills per day. This is mathematically incorrect.

Here is a correct procedure to derive the number of approaches per day:

Number of approaches per year = number of landings per year = 1/2 of number of operations per year. (One operation is eather one takeoff or one landing.)
High range: 15,300 / 2 = 7,650; Base range: 10,600 / 2 = 5,300.
Number of approaches per day = number of approaches per year divided by 365.
High range: 7,650 / 365 = 20.96; Base range: 5,300 / 365 = 14.52
Number of approaches per day over El Dorado Hills = (number of approaches per day) * (fraction of approaches over El Dorado Hills)
** Mather arrivals include approaches from the north and from the south that do not overfly El Dorado Hills or Folsom.
At the time of this initial draft the current value of that fraction, based on flight track data from one week in March, 2008 is 0.62 (62% of approaches overfly EDH).
High range: 20.96 * 0.62 = 12.995; Base range: 14.52 * 0.62 = 9.002
Rounded to nearest integer, the values are 13 approaches per day for the high range, 9 approaches per day for the base range.
Number of morning approaches per day over El Dorado Hills = (number of approaches per day) * (fraction of approaches over EDH occurring in morning hours). This is of interest due to the frequent citation of sleep disturbance in connection with freighter noise. Also, if not for this factor the rate of noise events would be substantially higher from operations by business jets and Air Force T-38s than from air carrier cargo operations.
At the time of this initial draft that fraction is 31%, based on flight track data from one week in March, 2008.
High range: 20.96 * 0.31 = 6.4976; Base range: 14.52 * 0.31 = 4.5012
Rounded: 6.5 approaches per day for high range, 4.5 approaches per day for base range.

Summary of forecast, Mather air carrier cargo operations
	High Range	Base Range
Operations per year	15,300	10,600
Approaches per year	7,650	5,300
Averages:
Approaches per day	20.96	14.52
Approaches per day over El Dorado Hills & Folsom	13	9
Approaches per day in a.m. over El Dorado Hills & Folsom	6.5	4.5

At this time all a.m.approaches over El Dorado Hills and Folsom normally occur between about 3:45 a.m. and 6:30 a.m. Flight delays occasionaly result in later approaches.Early arrivals occasionally cross EDH as early as 3:30 a.m.

Approaches per year over EDH and Folsom are:
High range: (15,300/2) * .62 = 4,743
Base range: (10,600/2) * .62 = 3,286

Source reference:
Operation rate forecast data from the Mather Airport Master Plan,
with highlighting added to portions for air carrier cargo operations
Mather forecast summary, highlighted