Glossary

In principle, aircraft always take off and land against the wind. Statistically, there is predominantly (approx. 60 to 70% of the year) a westerly wind situation at BER, in which case operating direction 25 applies. The designation is based on the take-off and landing direction. Just like the compass dial on a compass, the designation 25 is used for take-offs and landings in a westerly direction because the approaches and departures then take place in the direction rotated 250° clockwise with respect to north.

In the opposite case (easterly wind), operating direction 07 applies; this corresponds to 70°. Depending on the weather, the operating direction can change several times a day.

A characteristic feature of noise pollution from air traffic is the alternation between intensive, short-term noise events and the “noise breaks” that depend on the traffic density. The equivalent continuous sound level was introduced as a measure of the average noise exposure in a given period. It is a calculated value that is determined from the sound level curve of the individual noise events registered at the measurement location and the ratio of the sum of the event durations and the total measurement time. Depending on the type of noise to be assessed, different formulas are used for the calculation. These are partly fixed in relevant legal texts.

Section 19a of the Air Traffic Act prescribes the operation of measuring equipment for aircraft noise monitoring in the vicinity of commercial airports. For quantitative assessment, equivalent continuous sound levels are used in accordance with Section 3 of the Aircraft Noise Act. Technical details are laid down in DIN 45 643, the new edition of which was published in February 2011. The measuring system of the FBB has met this standard since September 2010.  

The Leq diagrams are differentiated according to day and night for each measuring point. Only aircraft noise is taken into account in the diagrams. The daily continuous sound levels are shown as a bar diagram. Days on which, because of failure, measurements were available in less than 50% of the reference time or on which there were no aircraft movements relevant for this measuring point are not indicated. The continuous sound level for the entire month appears below the heading. Sound levels within downtimes are not taken into account. When calculating the continuous sound level, only the failure-free time is taken as the total time (T).

In addition to the average noise exposure, the frequency and level of individual noise impacts from aircraft movements is considered an important parameter for assessing exposure. The number of aircraft noise events per month is shown for each station and broken down by level classes, each one dB wide (bars). The events are displayed separately according to day-time and night-time (10:00 p.m. to 6:00 a.m.). The solid curve describes the cumulative frequency situation of the maximum levels. This indicates the percentage of all aircraft noise events in the month that exceeds a certain level. At measuring points where the maximum levels of take-offs and landings differ considerably, two-peaked bar diagrams result.

In the measuring point report, key figures of the individual measuring points are given for each day. These are in detail:

N1: Number of aircraft noise events recorded

N2: Number of flight events relevant for measuring point. This figure is highly dependent on the location of the measuring point.

N2+: Like N2 except for that aircraft movements within outage periods are not taken into account.

N1/N2: Proportion of relevant aircraft movements for which valid measurements are available
Availability: Availability of the measuring point related to the acoustic day from 6:00 to 6:00 a.m.

Night flights are particularly critical for noise pollution. From these diagrams, the number of take-offs and landings per month in each hour of the night, which are distributed among the different noise categories, can be read. 

The noise exposure at a given measurement location can vary considerably depending on the runway on which the take-offs or landings take place and the direction. A particularly characteristic example of this dependence is measuring station 06 at BER. Comparing the daily values of the equivalent continuous sound level with the numbers of movements in the two traffic directions 07 and 25 (overview diagrams monthly Leq), a lower noise pollution with traffic in the west direction (25) can clearly be recognised.

The first of these diagrams shows the total number of aircraft movements (take-offs and landings) broken down by noise category of the aircraft (“aircraft mix”). A distinction is made between aircraft according to ICAO Annex 16 Chapters 2, 3, and 4, propeller-driven aircraft (including turboprops), and small aircraft with a maximum permissible take-off mass of < 5.7 tonnes. In the case of Chapter 3 aircraft, an additional distinction is made according to whether they are included in the bonus list of the Federal Ministry of Transport, Building and Urban Development (i.e. whether they fall considerably below the noise limits stipulated in Annex 16). The influence of the aircraft mix results primarily from the considerably higher noise emissions of the obsolete and now largely retired Chapter 2 aircraft compared with the aircraft predominantly in use today. 

The first of these diagrams shows the total number of aircraft movements (take-offs and landings) broken down by noise category of the aircraft (“aircraft mix”). A distinction is made between aircraft according to ICAO Annex 16 Chapters 2, 3, and 4, propeller-driven aircraft (including turboprops), and small aircraft with a maximum permissible take-off mass of < 5.7 tonnes. In the case of Chapter 3 aircraft, an additional distinction is made according to whether they are included in the bonus list of the Federal Ministry of Transport, Building and Urban Development (i.e. whether they fall considerably below the noise limits stipulated in Annex 16). The influence of the aircraft mix results primarily from the considerably higher noise emissions of the obsolete and now largely retired Chapter 2 aircraft compared with the aircraft predominantly in use today.