13) On July 10th, 2003, the CSAAB chose the WEST configuration as PREFERENTIAL after a long period of CSAAB meetings and research undertaken by AENA.

A) What does PREFERENTIAL configuration mean ?

B) What was the situation like in the beginning ?

C) What was the decision making process ?



OACI defines a preferential configuration as one that is maintained until it reaches a tailwind limit of 5 knots with taking off trajectories in the same direction at 15 degrees.

In the case of the Barcelona airport, the wind limit implies that 15% of the time the tailwind exceeds this limit. The configuration calculation of the study is as follows:

85% of the time: preferential configuration
15% of the time: NON preferential configuration

The Environmental Impact Declaration (D.I.A.) demands that the towns affected by the PREFERENTIAL CONFIGURATION be soundproofed, thus this decision carries great importance.

The D.I.A. also gives the CSAAB legal authority to decide the PREFERENTIAL CONFIGURATION.




The Environmental Impact Report was carried out with the East configuration in mind as preferential, which would result in 65dB during the day and 55dB at night. This included a good part of Gavà Mar and Castelldefels beach within the sound range:

Envolvente 65dB diurnos y 55dB nocturnos en el aeropuerto del Prat según el Estudio de Impacto Ambiental

The Environmental Impact Report, later called the Environmental Impact Declaration, gave AENA and the General Management of Civil Aviation (DGAC - Direcció General d'Aviació Civil) one year from its date of publication to undertake any research needed, before taking actions related to sound emissions, to find out if in the future it would be more favorable to use the WEST configuration, as long as the safety of the people and airplanes is guaranteed, in order to minimize acoustic impact.



During CSAAB's sixth meeting held on October 31st, 2002, Vicente Navarro, representative of Gavà City Council, asked about the progress of the research being done on the WEST configuration.

Javier Montoro (Pla Barcelona) responded that the study would be completed before the end of the year 2002 and would be presented to the commission within the timeframe set out by the D.I.A.


During CSAAB's eighth meeting held on December 19th, 2002, Javier Montoro (Pla Barcelona) showed the results of the study pertaining to the WEST configuration.

Antoni Padilla (Mayor of Castelldefels) (PSC) The mayor of Castelldefels, Antoni Padilla, affirmed that the sound range of this configuration affects populated areas that were not affected by the EAST configuration.


On January 23rd, 2003 a technical meeting was held to discuss the research done on the preferential configuration of the airport of El Prat. The meeting was directed towards resolving questions about the interpretation of the document that AENA had presented as well as presenting additional information that the City Council of Castelldefels had requested.

Fernando Arenal and Francisco Escriu (AENA) explained the criteria they followed to choose the trajectories of the planes. They clarified that takeoffs in WEST configuration would head towards the NBD in Vilanova flying over agricultural zones and less populated areas in the first part of the ascent, and thus avoiding maneuvers which produce a greater noise level.

In response to a question from the City Council of Castelldefels, Francisco Escriu clarified that the expected trajectories would divert a maximum of 8 degrees from the axis of the main runway due to the presence of the Garraf massif.


Thus, AENA had chosen the following taking off operation in WEST configuration:

  • From the main runway (25R): difference of 7 degrees from the axis of the runway towards the interior
  • From the third runway (25L): difference of 15 degrees from the axis of the runway towards the sea in order to avoid flying over Gavà Mar

Javier Montoro (Pla Barcelona) explained that in accordance with the limits of 65dB and 55dB(A) outlined in the D.I.A., the difference between the two configurations is an initial assessment of

- Only 20 houses affected in WEST configuration
- 2,000 houses affected in EAST configuration

In addition, the nighttime period poses the most problems

City Council of Castelldefels The City Council of Castelldefels asked why the scenario planned for 2004 and takeoffs from the transverse runway weren't included in the study. Javier Montoro (Pla Barcelona) avoided the question by affirming that its effect was already taken into account in the sound range of the scenario for 2015.

The City Council of Castelldefels also asked if there was a possibility to establish sound quotas that would distribute noise throughout the territory. Javier Montoro (Pla Barcelona) responded that this procedure was causing a lot of problems in airports where it was applied such as Amsterdam-Schipol. In Amsterdam they were starting to give it up.

Ignasi Rucabado (Technician of Gavà City Council) The technician of Gavà City Council (Ignasi Rucabado) asked about the possibility of increasing the deviation degree from the main runway towards the interior. Francisco Escriu (AENA) avoided the question delegating it to Air Space.

City Council of El Prat de Llobregat The City Council of Prat put forward the European Union's guideline to lower the daytime limit from 65dB to 55dB and the nighttime limit from 55dB to 45B. Javier Montoro responded that these new limits appeared in the guideline as graphic limits and not sound limits.

Francisco González (Pla Barcelona) reiterated that the D.I.A. established the limits of 65dB and 55dB, therefore, that was the valid reference. He also affirmed that when new limits were to be established in the future, then the analysis of adapting to these new limits would be taken into consideration.

City Council of Castelldefels

The City Council of Castelldefels asked to add a maximum noise level Leq(max) to the study. Javier Montoro affirmed that the study of maximum noise levels only makes sense when applied to noise reduction procedures to be carried out in the second phase (later on) as outlined in the D.I.A.



In CSAAB's tenth meeting (March 6th, 2003), Javier Montoro (Pla Barcelona) presented the development of the technical meeting on the 23rd of January and he argued in favor of the STRONG points of the WEST configuration

- The affected population (according to limits in the D.I.A.) is less than with the EAST configuration
- The opportunities of reducing noise are greater than in the EAST configuration (landings)

City Council of Castelldefels The City Council of Castelldefels asked for more time to integrate all the information received from AENA. It was agreed to allow one month and a half's time to approve the preferential configuration.



In CSAAB's thirteenth meeting (July 10th, 2003), the City Council of Castelldefels turned in a document to all the attendees: "Summary of the City Council of Castelldefels' position on the preferential configuration for plane taking off and landing operation in the Barcelona Airport", along with a letter written by the Federation of Residents Associations of Castelldefels

Antoni Padilla (Mayor of Castelldefels) (PSC)

The mayor of Castelldefels (Antoni Padilla) explained that Castelldefels already supported so many metropolitan servitudes that it had become a saturated corridor; he did not want to take on any more. He maintained his stance for designating the EAST configuration as preferential

The City Council of Gavà continued to back up the WEST configuration as preferential. The City Councils of El Prat and Barcelona also backed up this configuration. AENA, the Ministry of the Environment, the Ministry of ‘Fomento’ and the Environmental Department also backed it up. The City Council of Castelldefels was the only defender of the EAST configuration, thus the WEST configuration became preferential as reflected in the meeting act:

Aprobación de la configuración OESTE como preferente (10 de julio de 2003)