PALO ALTO
AIRPORT
PUBLIC WORKS DEPARTMENT
2024
ANNUAL NOISE REPORT
(January 2024 to
December 2024)
Vision: Palo Alto Airport strives to balance the
interests of pilots to fly with the interests of
neighbors in a peaceful living environment. This
document is a report of the noise complaints
received by the airport in 2024. Airport staff uses
this information to identify trends within Palo Alto
and neighboring communities. These trends inform
communications between airport staff and pilots on
the issue of noise.
Introduction:
The following is a report on noise-related operations and complaints received by Palo Alto Airport (PAO) in 2024. The Federal Aviation Administration (FAA) defines air travel routes and procedures, including defining separation distances between aircraft, determining hazards to aviation and all other safety criteria for aircraft, and is responsible for directing and enforcing the movement of aircraft in flight.
Although organizations can petition the FAA regarding flight procedures, the FAA has the final say in what is safe and acceptable. The Airport Noise and Capacity Act (ANCA) of 1990 federally prohibits public-use airports from restricting airspace.
The FAA measures noise based on the Yearly Day and Night Average Sound Level (DNL) and the Community Noise Equivalent Level (CNEL). While both are essentially the same, airports in California use the CNEL method to measure noise. CNEL is a method of averaging single event aircraft noise into a weighted 24-hour average. The system adds penalties to all events occurring during the evening (7pm – 10pm) and the night (10pm – 7am). The Santa Clara County Airport Land Use Commission (SCC ALUC) performed a noise study for the Palo Alto Airport using the CNEL to determine the noise contours for 55, 60, 65, and 70 decibels. The contour map is included as Attachment A.
Regarding safety and altitude, the FAA has in place Federal Aviation Regulations (FARs) that establish Minimum Safe Altitudes (MSAs) for aircraft. For fixed wing aircraft, the MSA is 1,000 feet above ground when over congested areas and 500 feet when not over congested areas. These MSAs apply to all fixed wing aircraft except when necessary for landing and takeoff operations. Helicopters are exempt from these altitude restrictions due to the nature of their flight. These minimum altitudes are enforced by the FAA Flight Standards District Office in San Jose, not by Palo Alto Airport. Palo Alto Airport cannot tell pilots when or where to fly; the Airport, however, does have voluntary noise abatement procedures that Palo Alto Airport recommends that pilots follow. (See the Noise Abatement Procedures section below.) The Airport receives noise complaints via email at [email protected] and a noise complaint hotline 650-329-2405. Airport staff review and timely respond to all complaints, ascertaining information from complainants including contact information, date, time, and description of the occurrence. Various flight trackers can be used to help identify the aircraft involved and verify if FAA regulations or Palo Alto Airport procedures were violated. The Airport staff reviews and compiles all data to determine trends with flying activities.
Purpose:
The purpose of the Palo Alto Airport Annual
Noise Report is to identify noise trends in the
surrounding areas and determine compliance
with established voluntary noise abatement
procedures.
Airspace:
The Palo Alto Airport airspace is unique. The
congested Bay Area airspace is dominated by
SFO Class Bravo airspace, which encompasses
a 30 nautical mile radius around SFO.
Underneath the Class Bravo airspace lies the
Class Charlie airspace of Oakland and San Jose
International Airports. Finally, Moffett Airfield lies approximately 4 nautical miles to the southeast of Palo Alto Airport.
As a result, Palo Alto Airport airspace ends only 1.5 nautical miles southeast of the Palo Alto Airport’s single runway (Runway 13/31). To land at Palo Alto Airport, aircraft must turn before entering Moffett’s airspace, resulting in aircraft having to space themselves in traffic patterns over the peninsula when takeoff/landing volumes peak. The FAA’s Air Traffic Control Tower (ATCT) at Palo Alto Airport has a letter of agreement with Moffett’s ATCT providing Palo Alto Airport aircraft with extensions into Moffett airspace when Moffett airfield is not in use. The additional airspace is a useful mitigation tool during busy times.
Further restrictions in Palo Alto Airport airspace come from San Jose Class C airspace, starting at 1,500 feet Mean Sea Level, just southeast of Palo Alto Airport and SFO Class B airspace, starting at 2,500 feet Mean Sea Level, just northeast of the Palo Alto Airport. Both are identified on the Palo Alto Airport Sectional Map: San Jose Class C is shown with thick magenta lines and SFO Class B is shown with thick blue lines. These restrictions play a vital role in aircraft departures, in turn influencing noise abatement procedures for the Palo Alto Airport.
Noise Abatement Procedures:
Noise abatement procedures are voluntary procedures that the Airport asks pilots to follow. The Airport is prohibited from restricting airspace. Palo Alto Airport staff will speak with individual pilots and educate them about the voluntary noise abatement procedures. The Palo Alto Airport cannot levy fines on pilots that violate the voluntary noise procedures. For illustrated noise abatement procedures reference Palo Alto Airport Pilots Handout included as Attachment B.
The noise abatement procedures depend on the runway that is in use at the time. Depending on weather patterns, aircraft can depart on Runway 31 to the northwest or Runway 13 to the southeast.
Approximately 90% of the time, weather conditions require the use of Runway 31. Pilots are asked to not make a left crosswind departure from Runway 31, but instead make a “Left Dumbarton Departure” (fly to the Dumbarton Auto Bridge before making a left turn and flying over East Palo Alto) or a right 270 degree turn before departing to the south or west. When aircraft are using Runway 13, pilots are asked Palo Alto Airport Sectional Map
Palo Alto Airport in Green
PAO Airspace highlighted in Red
Source: http://vfrmap.com/?type=vfrc&lat=37.461&lon=-122.115&zoom=10 to make a left 270-degree turn. In addition to these procedures, pilots are asked to climb to 1,500 feet or above ground before crossing Highway 101 and reduce power when safely able.
For arrivals, it is standard practice and necessary for pilots to descend to pattern altitude before entering the traffic pattern around PAO, sometimes requiring aircraft to descend below the 1,500 feet minimum of departing aircraft over Palo Alto. As these aircraft are descending to land the engines are generally powered back and quieter than ascending aircraft.
Airport staff continuously engage with tenants and pilots about the voluntary noise abatement procedures, always noting that safety always supersedes noise.
Findings:
The Palo Alto Airport remains one of the busiest general aviation Airports in the Bay Area with an average of 150546.8 operations per year since 2015. Airport Operations for the calendar year of 2024 increased .17% compared to the calendar year 2023. An operation is defined as either a takeoff or a landing and a touch-and-go procedure will account for two operations.
Table 1. Airport Operations for Palo Alto Airport
Year Air Taxi Military Total Year
Air
Taxi Military Total
2005 2397 28 184821 2015 1082 118 172132
2006 1932 17 176570 2016 708 52 153238
2007 1440 318 181883 2017 872 146 148769
2008 1697 280 174332 2018 760 133 146181
2009 1650 301 155556 2019 920 63 150266
2010 2077 6 158217 2020 620 45 112712
2011 1572 8 170389 2021 566 23 158568
2012 1700 16 176564 2022 636 37 163620
2013 1628 14 172653 2023 763 21 149859
2014 1518 22 179900 2024 666 29 150123
AVG 1761.1 101 173088.5 AVG 759.3 66.7 150546.8
During the 2024 Calendar year, the Airport logged 110 total noise complaints from 51 households. While the quarterly household counts add up to 60, the actual total unique households for 2024 are 51. This difference occurs because some households submitted complaints in multiple quarters, but they are only counted once in the yearly total. Table 2 shows the number of complaints by quarter and includes the totals from 2023.
Table 2. Complaints Received
Quarter 1 Quarter 2 Quarter 3 Quarter 4 Total 2024 Total 2023 Complaints 20 24 37 29 110 256
Households 11 13 16 20 51 23
Table 3 sorts the complaints logged into three sections. The first one is PAO which includes all complaints that involve aircraft that performed an operation at the Airport. The next section is General, which includes complaints that did not include a specific aircraft or incident of noise. These complaints may or may not involve aircraft from PAO. The last section is non-PAO, which include aircraft that are not based or did not operate at the Airport. These flights may include California Highway Patrol, Coast Guard, Air Taxis, Pipe Surveys, Stanford Life Flight, Angel Flights, and banner towing operations. Also included in Table 3 are the totals for 2023.
Table 3. Aircraft Association
Quarter 1 Quarter 2 Quarter 3 Quarter 4 Total 2024 Total 2023 PAO 16 18 32 22 88 236
General 2 3 1 5 11 4
Non-PAO 2 3 4 2 11 16
Table 4 below provides a detailed breakdown of the 110 complaints by City. Most complaints came from the City of Palo Alto, with 54 complaints logged from 12 households.
Table 4. PAO Noise Complaints by City
Quarter
1 Quarter 2 Quarter 3 Quarter 4 Total
2024 Total 2023
City C H C H C H C H C H C H
Cupertino 1 1
East Palo Alto 5 3 3 2 6 5 2 2 16 10 4 4
Half Moon Bay 2 1 6 2 8 2
Ladera 3 3 3 3
Livermore 1 1 1 1
Los Altos 4 1
Menlo Park 12 2
Mountain View 1 1 1 1 1 1
Newark 2 2 3 3 2 2 7 7 1 1
Palo Alto 7 3 14 5 25 6 8 4 54 15 227 8
Pleasanton 1 1 1 1 2 1
Portola Valley 2 1 2 1 4 1 1 1
San Jose 3 1 1 1 4 1
Stanford 1 1 1 1 2 2
Sunnyvale 2 1 3 3 5 3 1 1
Union City 1 1 1 1
Unknown 1 1 1 1 2 2 1 1
Woodside 1 1 1 1 1 1
Total 21 12 24 13 37 16 29 20 110 51 256 23
Table 5 below shows the general type of aircraft identified as causing noise complaints at the Airport.
There are 2 types of engines for aircraft utilizing PAO. The first is reciprocating which is similar to an automobile engine, and the second is turboprop which is a turbine engine with a propeller that produces thrust. Aircraft are further differentiated by “multi” and “single” which denotes the number of engines for the aircraft. As Table 5, shows single reciprocating aircraft produced the largest portion of noise complaints. This class of aircraft represents most of the fleet at PAO and usually consists of Cessna, Piper, and Cirrus aircraft.
Table 5. Aircraft Type
Helicopter Multi-
Reciprocating
Multi-
Turboprop
Single-
Reciprocating
Single-
Turboprop Unknown Drone
2024 Complaints 7 2 5 68 10 6
2023 Complaints 1 3 4 127 7 101 9
Table 6 below shows the number of violations of the established noise abatement procedures. Airport staff makes every effort to talk to all pilots that violate these procedures, but it is difficult to talk to all transient pilots about noise abatement procedures. It is not the role of the FAA Air Traffic Control Tower to advise pilots of the noise abatement procedures, however, the City has developed a working relationship with the Air Traffic Control Tower (ATCT) and Air Traffic Controllers do advise pilots of the noise abatement procedures when they have the ability to do so.
Table 6. Observed Violations of Noise Abatement Procedures Quarter 1 Quarter 2 Quarter 3 Quarter 4 Total
Tenant 2 6 7 4 19
Transient 1 4 7 2 14
Unknown 1 1 2
Total 3 10 15 7 35
Complaints 20 24 37 29 110
Operations 33,061 40,904 41,267 34,891 150123
% Compliance 99.94% 99.94% 99.91% 99.91% 99.93%
Attachment A
PAO Noise Contour Map
Following is a noise contour map for PAO, adopted by the Santa Clara County Airport Land Use Commission (SCC ALUC) in their 2008 Comprehensive Land Use Plan, reflecting the forecasted noise contours for Palo Alto Airport in 2022.
SCC ALUC used the Integrated Noise Model which considers airport altitude, mean temperature, runway configuration, aircraft flight track definition, aircraft departure and approach profiles, aircraft traffic volume and fleet mix, and flight track utilization by aircraft types. All data is entered into the CNEL formula to prepare the noise contours for Palo Alto Airport.
The 65 decibel (dB) noise level of the Airport extends beyond the airport boundaries, but is only over Palo Alto Golf Course, Palo Alto Baylands Nature Preserve, and the salt marshes in San Mateo County.
Refer to https://stgenpln.blob.core.windows.net/document/ALUC_PAO_CLUP.pdf, for a more detailed description of how the SCC ALUC prepared this map.
2022 Forecasted Palo Alto Airport Noise Contour Map
Attachment B
PAO Pilot Handout
Santa Clara County created a Pilot Handout for Palo Alto Airport that described the noise abatement procedures. When the City of Palo Alto assumed control of the Airport, the existing noise abatement procedures were adopted, with one exception, “pilots must maintain 1,500 feet or above across Highway 101” was replaced with “Aircraft are asked to climb to and maintain at least 1,500 feet before crossing Highway 101.” The change is consistent with the voluntary nature of noise abatement procedures as Airports are Federally prohibited from instructing pilots how to fly. In 2024, Airport staff worked with airport users and FAA Air Traffic Controllers to update the handout to better illustrate the Airports Voluntary Noise Abatement Procedures.
Attachment C
Map of Palo Alto Households
39 1
39 1
1 1
1 2
39 1
There were 7 complaints
from 7 households that
did not provide
addresses.