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IS MISSION BEACH ON ITS WAS TO 24 HOURS OF SAN DIEGO INTERNATIONAL AIRPORT AIRCRAFT NOISE

ASSESSMENT OF 24 HOURS OF AIRCRAFT NOISE ON HUMAN RESPONSE IN SOUTH MISSION BEACH

October 4 2026[i]

For years the FAA and the City/County operations an informal nighttime noise abatement departure from 10 pm to 6:30 am. This departure was implemented along with other temporary measures during an extreme period of noise in the 1960-70s. While other measures were stopped after 1-2 years, the nighttime measure was continued.

During the recent Part 150 study, the Airport Authority and the FAA attempted to formalize the nighttime procedure, but the effort failed when a few of us pushed back on the plan. Then, the FAA illegally implemented its own formalization of the nighttime procedure calling it the CLSSY SID. They failed to following the FAR Part 161 procedure. Now, between the PADRZ and the CLSSY SIDS, 100 percent of the nighttime (10 pm to 6:30 am departures cross over South Mission Beach.

As it turns out, the departures on CLSSY that fly to destinations east of San Diego, including the east coast, are far louder than those that depart on the PADRZ SID with destinations to our north.

The measurements

The 24-hour record contains 202 aircraft events. Each peak is the maximum slow A-weighted level (LASmax) during that overflight. The distribution is tight: the mode is 73 dB, the median is 72.7 dB, and the loudest event is 77.7 dB.

The record used is the continuous Larson Davis run from 4 Oct 2026 16:15:51 to 5 Oct 2026 16:16:41 (86,451 one-second samples). An event is a stretch at or above 65 dB LASmax lasting at least 5 seconds. Stretches separated by 60 seconds or less are one event; a longer gap starts the next. The shortest gap between peaks in this file is 75 seconds, so the one-minute rule does not split or join overflights. Time above 65 dB is typically 14 seconds.

A bin of 72 means 72.0 ≤ peak < 73.0 dB. Of the 202 events, 178 (88%) peaked at 70 dB or higher and 28 (14%) at 75 dB or higher. Mean peak is 72.6 dB; median SEL is 81.2 dB. Nothing rose above 65 dB between 23:00 and 05:00. The loudest retained event is 77.7 dB at 08:14:25 on 5 Oct.

Lowering the threshold to 60 dB adds the quiet tail and raises the count to 246. The mode stays in the 72–74 dB bins.

The workbook has the 202-event list, the histogram as formulas against that list, and the chart.

Almost every event in this histogram sits at or above the single-event levels that have produced measurable cardiovascular stress in controlled studies. The day as a whole also sits well above the WHO aircraft guidelines, which are set on average exposure, not on the peak of one overflight.

Two scales are in play, and they should not be mixed. Chronic risk is judged from outdoor Lden and Lnight. Acute cardio-stress — adrenaline, blood pressure, endothelial function — has been shown from indoor event peaks around 60 dB and from a night equivalent level near 45 dB, even in healthy adults.

Where this day sits

From the 202 events, aircraft-only energy (ambient excluded) is about 56.6 dB by day, 57.3 dB in the evening, 49.1 dB at night, and 59 dB Lden. The WHO European guideline is aircraft noise below 45 dB Lden and below 40 dB Lnight, because levels above those are associated with adverse health effects, including sleep disturbance and, in the supporting review, ischemic heart disease.   That review put the relative risk of incident coronary disease at about 1.09 per 10 dB of aircraft Lden.   This day is roughly 14 dB above the Lden guideline and 9 dB above the night guideline. A single day is not a chronic dose, but it is not a quiet day either: aircraft, not the background, dominate the energy.

Single-event comparison

The cleanest human experiment is the Mainz aircraft-noise series. Healthy adults played 30 or 60 overflights in the bedroom, average indoor maximum about 60 dB(A) and night Leq about 43–46 dB, had worse sleep, higher morning adrenaline, a rise in blood pressure of about 5 mmHg, stiffer arteries, and reduced flow-mediated dilation the next morning.   In people with coronary disease or elevated cardiovascular risk, 60 events at an indoor Leq of 46.9 dB raised systolic pressure about 4 mmHg and impaired endothelial function, independent of how annoyed the subject felt.   A later trial held Leq near 45 dB and varied the count from 60 to 120 events: vascular impairment was similar, and the cardiac effect tended to grow with event count.  

This meter is outdoors. Indoor level is outdoor peak minus the window loss, roughly 15 dB open, 20 dB partly open, 25 dB closed.

With windows open, all 202 events reach an indoor peak of at least 50 dB, and the 28 events at or above 75 dB outdoors match the 60 dB indoor maximum used in the endothelial studies. With windows closed, none reach that 60 dB indoor mark, but 178 still reach 45 dB indoors, which is the start of the range where EEG and behavioral awakening curves rise.   Chronic night exposure at outdoor Lnight of 45 dB and above has also been linked to larger ventricular volumes, thicker walls, and worse strain on cardiac MRI.  

What the shape of the histogram adds

The distribution is not a few outliers on a quiet background. The mode is 72–73 dB, 178 of 202 events are at or above 70 dB, and the 13 events in the 23:00–07:00 night all peaked between 70.4 and 77.6 dB. That is a smaller night count than the 30–60 event laboratory nights, which matters: the acute vascular effect tracks both level and number of events. The load here is shifted into the evening. The 21:00 hour alone had 23 events, median peak still about 72.6 dB. There is a real gap from 23:00 to 05:00, so this particular night is not a Schmidt-type 60-event night. The evening and early-morning shoulder is.

The practical reading is that the bulk of the histogram, not the tail, is the cardio-relevant part. A 65 dB outdoor event is already in the indoor awakening range with a window open. The typical 73 dB event is in the range shown to raise adrenaline and blunt endothelial function if the facade loss is about 15 dB, and still in the sleep-disturbance range if the loss is 25 dB. The four events at 77 dB are the top of that same distribution, not a separate class.

What does this tell us about the noise

This is a busy aircraft day, not a background-noise day. The meter heard 202 separate overflights in 24 hours, and most of them were loud enough to matter indoors.

The typical event peaked at 72–73 dB outdoors. That is the middle of the histogram, not the tail: 150 of the 202 events fell between 70 and 74 dB, and 28 reached 75–77.7 dB. Each one lasted about 14 seconds above 65 dB, then dropped, with the next one at least 75 seconds later. That shape — a short rise, a peak near 73 dB, a clean gap — is an overflight, not surf, traffic, or a neighbor.

The quiet hours confirm it. Nothing above 65 dB occurred between 23:00 and 05:00. The load is in the operating day and the shoulders: 137 events from 07:00 to 19:00, 52 from 19:00 to 23:00, and 13 in the early morning, all of those last 13 still peaking between 70 and 77.6 dB. The 21:00 hour alone had 23 events.

On energy, aircraft dominate this record. Aircraft-only exposure for the day is about 59 dB Lden and 49 dB Lnight. The WHO aircraft guidelines are 45 dB Lden and 40 dB Lnight.   The meter’s all-source Lden was 61.5 dB, so other sources added little. A single day is not a yearly dose, but this day is about 14 dB above the level WHO associates with adverse effects.

Indoors, the same events land on the levels used in the cardiovascular studies. With a window open, a 73 dB outdoor peak is about 58 dB inside, and the 28 events at 75 dB or above reach the 60 dB indoor maximum that raised adrenaline, blood pressure, and impaired endothelial function in overnight aircraft-noise trials.   With windows closed, those same events are nearer 48–53 dB indoors — below that 60 dB mark, but still in the range where sleep awakenings increase. The night count here, 13 events, is smaller than the 30–60 event laboratory nights, so the evening shoulder is the heavier part of this particular day.

What it does not say: one outdoor meter day does not diagnose heart disease, and it does not replace a yearly Lden at the facade. What it does say is that the noise at this site on 4–5 October was repetitive aircraft noise, centered near 73 dB, present most of the operating day, and above both the average-exposure guideline and the single-event levels linked to sleep and vascular stress.

[i]