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The day in figures

145 overflights counted today over Castelldefels.

Overflights today
8
take-offs
106
landings
31 flights are still under review
The wind, today and tomorrow
8.0
kt measured today
9.6
kt tailwind tomorrow
From the north-northwest, at 19:00, at the airport
7 h with overflights forecast, of 7 the forecast reaches
Flights last night
0
None. The 23:00–07:00 band, which the rules treat separately
The loudest aircraft today
84.9 dB
LAmax from the official network. Higher than nine out of ten we measure
Lowest altitude today
375 m
The overflight that passed lowest, from 00:00 to 23:59
Overflights in the period
1,301
7 days
1,875
14 days

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Today’s overflights145

145 overflights today ·

Analytics · Castelldefels

Data analysed to act on

We widen the view to identify patterns. We group the data into longer periods so as to identify room for improvement in how the airport is run, and take it to the competent authorities.

The analysis focuses on the environmental variables set down in current legislation (operating hours, weather, noise levels, among others) which shape how the airport is run and how much operational discretion it has. The end goal is to improve that management, to reduce the disturbance and to move towards a more balanced coexistence between airport activity and the people who live around it.

What 90 days say

Time coming in over the neighbourhood
19.1 %
measured
15-20 %
published
389 of 2,039 hours we were able to watch, across 90 days. 121 hours with no radar are left out
And by day, from 7:00 to 23:00
27.6 %
The band when people are out in the street with the windows open: 387 of 1,401 hours
Daytime landings with no published cause
38.9 %
4,267 of 10,965 daytime landings over the neighbourhood. That hour’s report published no tailwind worth the name, no storm, no wind shear, no low ceiling and no poor visibility
Night departures over the neighbourhood
28
overflights
1
with a wind that compels it
Across 23 separate nights, from 23:00 to 7:00. The airport’s own table does not contemplate this configuration at night
Night hours coming in over the neighbourhood
2 h
Not one hour between 23:00 and 7:00 across 90 days, out of 638 hours we were able to watch. This is a finding too
How long one of those days lasts
9.5 h
Average hours, consecutive or scattered, over the 41 days that had any. The worst reached 16 h. This is why the figure is given in hours and not in days

When we get flown over

Local hour × 90 days · Castelldefels

Tap a cell — or drag your finger across — to read that hour.

0 → 40 overflights/hDay · 07:00–23:00Night · 23:00–07:00No radar

DAYTIME LANDINGS: flights per hour against the wind

One mark per daytime hour —07:00 to 23:00— with landings over the neighbourhood · 90 days

Tap a dot —or drag your finger across the cloud— to read that hour.

Landings over the neighbourhood Tailwind on the preferred runway (kt)

No published causeThe weather report published a cause7 kt · The rules allow the change to be considered10 kt · The rules no longer require the preferred runway

163 hours of the 389 daytime hours with overflights —4,267 landings— fell to the left of 7 kt: there the airport’s weather report published no cause for abandoning the preferred runway.

No published cause does not mean unjustified. The airport’s published rules have a fifth clause —“traffic conditions, operational needs, safety situations and the remaining weather conditions”— that carries no threshold at all, and it is enough to cover any of these hours. What the chart shows is how much of what flies over us rests on the one clause that cannot be checked. The wind is that of the LEBL METAR, taken at each hour’s reading most favourable to the airport, gusts included.

NIGHT FLIGHTS: measured noise of each flight against the wind

One dot per flight over the neighbourhood —23:00 to 07:00— · 90 days

Tap a dot —or drag your finger across the cloud— to read that flight.

Peak noise measured (dB) Tailwind on the runway preferred at night (kt)

No published causeThe weather report published a causeNight landings7 kt · The rules allow the change to be considered10 kt · The rules no longer require the preferred runwayHow loud an ordinary landing sounds

1 of 24 take-offs happened with 10 kt or more of tailwind on the runway preferred at night, which is the threshold above which the rules no longer require it.

In the same period, 25 landings came in over the neighbourhood instead of over the inland side. They are in red because they are not measured by the same yardstick: between 23:00 and 07:00 the airport’s published rules contemplate no easterly configuration at all, so there is no written threshold either to cover them or to flag them.

The dashed horizontal line is the noise of an ordinary landing over this same neighbourhood, 72.9 dB. The median of these night take-offs is 80.5 dB. That is some 8 decibels above it, which at midnight and with the window open is perceived as almost twice as loud.

The median height of these take-offs is 553 m, and that of an ordinary landing over the neighbourhood, 382 m. So it is not that they pass lower: what you hear is not proximity, it is thrust —an aircraft taking off is at full power and one landing is not—.

Of these 24 night take-offs, 14 happened without the airport’s weather report publishing any of the four causes the airport’s published rules write down with a threshold. They rest on the fifth clause —“traffic conditions, operational needs, safety situations and the remaining weather conditions”— which carries no threshold and which nobody outside can check.

No published cause does not mean unjustified: the fifth clause covers any of these nights. “Published” means published in the airport’s weather report or in the maintenance notices (NOTAM), which are read too: if at that hour one of the runways the preferred configuration needs was closed, that flight does not appear in this cloud —its cause is on record—, and if the notice exists but its schedule cannot be read, the hour does not appear either, because rather than accuse or excuse without knowing, it says nothing. The direction and runway axis of each flight come from radar and from our own classification, not from a declaration by the airport operator. And daytime take-offs are not included here: by day, taking off along this axis is the configuration the rules prefer, and disputing it means disputing the runway-use agreement, not the discretion of the night shift.

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What this means

We look at the sky every 30 seconds to identify the aircraft flying over us right now. It is a provisional figure that we enrich with more information afterwards. Select any overflight to see its full record.

Every overflight of the day in a single list, from the most recent to the oldest. Here you will see the exact time of the overflight, the type of aircraft and, a few minutes later, whether that aircraft was taking off or landing. Select any overflight to see its full record.

Three cases are identified here: 1) when the runway that affects us is still in use at night, whether for take-offs or for landings; 2) when that runway is in use during an hour in which the airport’s weather report publishes none of the causes that allow leaving the preferred one; 3) when aircraft go over making more noise than the law allows (85 dB). Flights the airport does not answer for —state, medical, emergency or aerial-work flights, which are authorised to operate from any runway— are left out, and so are those whose kind is not yet known.

Here you will find aggregated data on the impact on the public.

Each cell represents one hour: days run horizontally and hours of the day vertically. The intensity of the cell is proportional to the number of overflights recorded in that hour, on the scale shown beside the chart. The vertical bands of higher intensity correspond to the periods in which aircraft come in to land over the neighbourhood instead of over the inland side: that is where most of the exposure is concentrated. Cells with diagonal hatching are hours with no radar coverage, and empty cells are hours that have not yet elapsed; neither of them are hours without traffic. Select a cell —or drag your finger across the matrix— to read below which hour it corresponds to and how many overflights it had.

Each dot is a daytime hour with landings over the neighbourhood. The vertical position shows how many aircraft went over in that hour; the horizontal one, the tailwind on the preferred runway —that is, the justification available for not using it—. The two vertical lines are the only thresholds the airport rules set down in writing: 7 knots to be able to consider the change, and 10 to stop requiring the preferred runway. Hours falling to the left of the first threshold are marked in amber: aircraft went over and the airport report published no cause. Select a dot to read its detail; if several hours coincide, all of them are shown, from the most recent to the oldest. The card also states whether the report published a thunderstorm, wind shear, a low ceiling or poor visibility, and knots are given to one decimal, exactly as the airport report records them.

Each dot is a flight that went over the neighbourhood between 23:00 and 07:00. The vertical position shows the peak noise the official sound-meter network measured as that aircraft passed; the horizontal one, the tailwind on the runway configuration the rules prefer in that period —that is, the justification available for not maintaining it—. The two vertical lines are the written thresholds, 7 and 10 knots, the same ones as in the previous chart; the dashed horizontal line is not a threshold but the noise of an ordinary landing over this neighbourhood, placed there as a point of comparison. Take-offs with no published cause are marked in amber. Landings are marked in red: in this period the rules contemplate no configuration by which they come in, so there is no threshold to measure them against. Select a dot to read the date, the time to the minute, the aircraft model and the height it passed at; if several coincide, all of them are shown, from the most recent to the oldest. Knots are given to one decimal, exactly as the airport report records them.