CJEC, 3rd chamber, June 14, 2007, No C-422/05

THE COURT (Third Chamber)

1 By its application, the Commission of the European Communities requests the Court to declare that, by adopting the Royal Decree of 14 April 2002 regulating night flights of certain types of civil subsonic jet aeroplanes (Moniteur belge of 17 April 2002, p. 15570) ('the Royal Decree of 14 April 2002'), the Kingdom of Belgium has failed to fulfil its obligations under Directive 2002-30-EC of the European Parliament and of the Council of 26 March 2002 on the establishment of rules and procedures with regard to the introduction of noise-related operating restrictions at Community airports (OJ 2002 L 85, p. 40) ('the Directive') and the second paragraph of Article 10 EC, read in conjunction with the third paragraph of Article 249 EC.

Legal background

Community legislation

2 In accordance with Article 17 of the Directive, the latter entered into force on the day of its publication in the Official Journal of the European Communities on 28 March 2002. The Directive introduced the concept of a 'balanced approach' to aircraft noise management and guidelines for imposing operating restrictions related to noise in European Community airports.

3 Article 2 of the Directive provides:

'For the purpose of this Directive:

...

(d) "marginally compliant aircraft" shall mean civil subsonic jet aeroplanes that meet the certification limits laid down in Volume 1, Part II, Chapter 3 of Annex 16 to the Convention on International Civil Aviation by a cumulative margin of not more than 5EPNdB (Effective Perceived Noise in decibels), whereby the cumulative margin is the figure expressed in EPNdB obtained by adding the individual margins (i.e. the differences between the certificated noise level and the maximum permitted noise level) at each of the three reference noise measurement points as defined in Volume 1, Part II, Chapter 3 of Annex 16 to the Convention on International Civil Aviation;

(e) "operating restrictions" shall mean noise related action that limits or reduces access of civil subsonic jet aeroplanes to an airport. It includes operating restrictions aimed at the withdrawal from operations of marginally compliant aircraft at specific airports as well as operating restrictions of a partial nature, affecting the operation of civil subsonic aeroplanes according to time period;

...

(g) "balanced approach" shall mean an approach under which Member States shall consider the available measures to address the noise problem at an airport in their territory, namely the foreseeable effect of a reduction of aircraft noise at source, land-use planning and management, noise abatement operational procedures and operating restrictions.'

4 Article 4 of the Directive, entitled 'General rules on aircraft noise management', provides:

'1. Member States shall adopt a balanced approach in dealing with noise problems at airports in their territory. They may also consider economic incentives as a noise management measure.

2. When considering operating restrictions, the competent authorities shall take into account the likely costs and benefits of the various measures available as well as airport-specific characteristics.

3. Measures or a combination of measures taken under this Directive shall not be more restrictive than necessary in order to achieve the environmental objective established for a specific airport. They shall be non-discriminatory on grounds of nationality or identity of air carrier or aircraft manufacturer.

4. Performance-based operating restrictions shall be based on the noise performance of the aircraft as determined by the certification procedure conducted in accordance with Volume 1 of Annex 16 to the Convention on International Civil Aviation, third edition (July 1993).'

5 Article 5 of the Directive, entitled 'Rules on assessment', states:

'1. When a decision on operating restrictions is being considered, the information as specified in Annex II shall, as far as appropriate and possible, for the operating restrictions concerned and for the characteristics of the airport, be taken into account.

...'

6 Article 7 of the Directive, entitled 'Existing operating restrictions', provides:

'Article 5 shall not apply to:

(a) operating restrictions that were already established on the date of entry into force of this Directive;

...'.

7 Under Article 16 of the Directive:

'Member States shall bring into force the laws, regulations and administrative provisions necessary to comply with this Directive by 28 September 2003 at the latest. They shall forthwith inform the Commission thereof.

...'

8 The Directive repealed Council Regulation (EC) No 925-1999 of 29 April 1999 on the registration and operation within the Community of certain types of civil subsonic jet aeroplanes which have been modified and recertificated as meeting the standards of volume I, Part II, Chapter 3 of Annex 16 to the Convention on International Civil Aviation, third edition (July 1993) (OJ 1999 L 115, p. 1).

9 According to Article 1 of Regulation No 925-1999:

'The objective of this Regulation is to lay down rules to prevent deteriorations in the overall noise impact in the Community of recertificated civil subsonic jet aeroplanes while at the same time limiting other environmental damage.'

10 Under Article 2 of that regulation:

'(1) "civil subsonic jet aeroplane" shall mean a civil subsonic jet aeroplane with a maximum certificated take off mass of 34 000 kg or more, or with a certified maximum internal accommodation for the aeroplane type in question consisting of more than 19 passenger seats, excluding any seats for crew only, and powered by engines with a by-pass ratio of less than three;

(2) "recertificated civil subsonic jet aeroplane" shall mean a civil subsonic jet aeroplane initially certificated to Chapter 2 or equivalent standards, or initially not noise-certificated which has been modified to meet Chapter 3 standards either directly through technical measures or indirectly through operational restrictions; civil subsonic jet aeroplanes which initially could only be dual-certificated to the standards of Chapter 3 by means of weight restrictions, have to be considered as recertificated aeroplanes; civil subsonic jet aeroplanes which have been modified to meet Chapter 3 standards by being completely re-engined with engines having a by-pass ratio of three or more are not to be considered as recertificated aeroplanes;

...

(4) "operational restrictions" shall mean weight restrictions imposed on the aeroplane and/or operational limitations within the control of the pilot or the operator, such as reduced flap setting;

...'.

11 Article 3 of Regulation No 925-1999 provides, with regard to non-complying aeroplanes:

'1. Recertificated civil subsonic jet aeroplanes shall not be registered in the national register of a Member State as from 1 April 1999.

2. Paragraph 1 shall not affect civil subsonic jet aeroplanes which were already on the register of any Member State on 1 April 1999 and have been registered in the Community ever since.

3. Notwithstanding the provisions of Directive 92-14-EEC and in particular Article 2(2) thereof, as from 1 April 2002 recertificated civil subsonic jet aeroplanes registered in a third country shall not be allowed to operate at airports in the territory of the Community unless the operator of such aeroplanes can prove that they were on the register of that third country on 1 April 1999 and prior to that date have been operated, between 1 April 1995 and 1 April 1999, into the territory of the Community.

4. Recertificated civil subsonic jet aeroplanes which are on the registers of Member States may not be operated at airports in the territory of the Community as from 1 April 2002 unless they have been operated in that territory before 1 April 1999.'

National legislation

12 The Royal Decree of 14 April 2002 entered into force on 1 July 2003. It is apparent from its preamble that during its adoption the legislature took account of, inter alia, Regulation No 925-1999, as well as of the imperative need to avoid legal uncertainty for operators resulting from the repeal of that regulation on 28 March 2002.

13 The Royal Decree of 14 April 2002 introduced night-time operating restrictions in all the airports situated on Belgian territory for certain types of recertificated civil subsonic jet aeroplanes in order to meet the standards set out in Volume 1, Part II, Chapter 3 of Annex 16 to the Convention on International Civil Aviation, signed in Chicago on 7 December 1944 (United Nations Treaty Series, Volume 15, No 102).

14 Article 1 of the Royal Decree of 14 April 2002 provides:

'During the night from 23.00 hrs local time until 06.00 hrs local time, civil subsonic jet aeroplanes shall be permitted to operate only where such aircraft are flying in clean configuration (landing gear and wing flaps retracted).'

15 Under Article 2 of that decree:

'Article 1 shall not apply:

1. to aircraft overflying Belgian territory in the course of a flight which has departed from and whose destination is a foreign country;

2. to civil subsonic jet aeroplanes which:

(a) are equipped with engines whose by-pass ratio is equal to or higher than three and which meet the standards in Annex 16 to the Convention on International Civil Aviation, Volume 1, Part II, Chapter 3, third edition (July 1993), or more stringent standards,

(b) or which from the outset, that is to say, without being recertificated, meet the standards referred to in point (a) above, or more stringent standards.'

16 According to Article 3 of the Royal Decree of 14 April 2002, the latter is to apply without prejudice to the provisions of Regulation No 925-1999. Article 4 of that decree set the date for its entry into force at 1 July 2003.

Pre-litigation procedure

17 On 6 June 2002, the Commission requested information from the Belgian authorities on the Royal Decree of 14 April 2002 and, in particular, on the grounds justifying maintenance of the reference to the engine 'by-pass ratio' criterion appearing in Regulation No 925-1999, even though when the Royal Decree was adopted that regulation had already been repealed and that criterion had not been retained in the Directive.

18 Since the response of the Belgian authorities of 28 June 2002 did not satisfy the Commission, the latter sent the Kingdom of Belgium a letter of formal notice on 24 October 2002, indicating that the measures taken during the period prescribed for transposing the Directive were liable seriously to compromise the result required by it and, for that reason, infringed the Directive and the second paragraph of Article 10 EC, read in conjunction with the third paragraph of Article 249 EC.

19 In their response of 23 December 2002, the Belgian authorities set out a number of arguments with a view to demonstrating that the Royal Decree of 14 April 2002 merely conferred formal status on a measure that was already 'established', within the meaning of Article 7 of the Directive, before the Directive's entry into force.

20 Since the Commission did not agree with the explanations provided, it sent a reasoned opinion to the Kingdom of Belgium on 3 June 2003, calling on that Member State to adopt the measures necessary to comply with it within two months of its notification. The Kingdom of Belgium replied by letter of 25 July 2003.

21 The Kingdom of Belgium notified the Commission of the adoption, on 25 September 2003, of the Royal Decree laying down the rules and procedures for the introduction of operating restrictions at Brussels National Airport (Moniteur belge, 26 September 2003, p. 47538). That royal decree, which is intended to transpose the Directive, entered into force on the day of its publication and did not repeal the Royal Decree of 14 April 2002.

22 Finally, the Commission brought the present proceedings pursuant to Article 226 EC.

The action

Admissibility

23 The Belgian Government disputes the admissibility of the action in so far as the originating application relies on the fact that the Royal Decree of 14 April 2002 had not been repealed when the measures implementing the Directive were adopted on 25 September 2003, that is to say, three days before the expiry of the period prescribed for transposition of the Directive, and the fact that that decree was maintained in force even after that period had expired. The Commission, it claims, extended the subject-matter of the dispute, inasmuch as the letter of formal notice and the reasoned opinion concern only the measures adopted during the period prescribed for transposition of the Directive, whereas, in the originating application, the Commission added the attitude displayed by the Belgian authorities after that period.

24 In that connection, the Belgian Government contends that, since that new head of complaint was not mentioned in the reasoned opinion, the defendant Member State was deprived of the opportunity to bring an end to the failure of which it was accused, or to express its views on that issue before proceedings were brought before the Court.

25 It must be recalled that, according to settled case-law, the letter of formal notice sent by the Commission to a Member State and the reasoned opinion issued by the Commission delimit the subject-matter of the dispute, so that it cannot thereafter be extended. The opportunity for the State concerned to submit its observations, even if it chooses not to avail itself thereof, constitutes an essential guarantee intended by the EC Treaty, adherence to which is an essential formal requirement of the procedure for finding that a Member State has failed to fulfil its obligations. Consequently, the reasoned opinion and the proceedings brought by the Commission must be based on the same complaints as those set out in the letter of formal notice initiating the pre-litigation procedure (see, in particular, Case C-191-95 Commission v Germany [1998] ECR I-5449, paragraph 55, and Case C-340-96 Commission v United Kingdom [1999] ECR I-2023, paragraph 36).

26 In this case, the Commission criticises the Kingdom of Belgium, in its reasoned opinion, for taking measures liable seriously to compromise the result prescribed by the Directive through its adoption of the Royal Decree of 14 April 2002.

27 Although it is true that, in the originating application, the Commission states that the Kingdom of Belgium did not repeal the Royal Decree of 14 April 2002 when it transposed the Directive and that after the period prescribed for transposition that royal decree was still in force, the fact none the less remains that such an observation, even if it was made only at the stage of the originating application, cannot constitute a new complaint. It is merely a finding of fact by the Commission that it may rely on in so far as the situation described may prove, first, that the situation had not changed since the expiry of the two-month period prescribed by the reasoned opinion and, second, as the Advocate General observed in point 56 of his Opinion, that the Royal Decree of 14 April 2002 was not a transitional measure intended to ensure continuity after Regulation No 925-1999 was repealed.

28 In that connection, it must be observed that when the Commission sent the reasoned opinion on 3 June 2003 the period prescribed for transposition of the Directive had not yet expired, the measures for its transposition had not been adopted, and the Royal Decree of 14 April 2002 had not yet entered into force.

29 In those circumstances, the Commission cannot reasonably be criticised for failing to mention in the reasoned opinion either the fact that the Royal Decree of 14 April 2002 had not been repealed when the measures for transposition of the Directive were adopted, or that the decree remained in force even after that period had expired.

30 It follows that the action is admissible.

The substance

31 In support of its action, the Commission relies on a single plea alleging that, during the period granted to the Member States for transposition of the Directive and while the latter was already in force, the Kingdom of Belgium adopted the Royal Decree of 14 April 2002, which, as regards the operating restrictions imposed on certain types of aeroplanes, follows the approach adopted by Regulation No 925-1999, which had already been repealed, and not that chosen by the Directive. Consequently, the result prescribed by the Directive, that is to say, the adoption throughout the Community of a homogenous framework for the introduction of operating restrictions for aeroplanes based a single definition of the meaning of aeroplanes which comply with the rules laid down in Volume 1, Part II, Chapter 3 of Annex 16 to the Convention on International Civil Aviation, was seriously compromised.

32 Under Article 4(4) of the Directive, performance-based operating restrictions are to be based on the noise performance of the aircraft as determined by the certification procedure conducted in accordance with Volume 1 of Annex 16 to the third edition (July 1993) of that convention, whereas, in order to establish operating restrictions, Article 2 of the Royal Decree of 14 April 2002 refers, in the same way as Regulation No 925-1999, to the concept of the engine by-pass ratio.

33 The Belgian Government contests the infringement on three grounds, first, that the Royal Decree of 14 April 2002 comes within the scope of Article 7 of the Directive, second, that it forms part of the Community legislature's objective because it fills the legal vacuum resulting from the repeal of Regulation No 925-1999 and, third, that it does not seriously compromise the result prescribed by the Directive.

The Royal Decree of 14 April 2002 comes within the scope of Article 7 of the Directive

34 The Belgian Government contends that the Royal Decree of 14 April 2002 comes within the scope of Article 7 of the Directive, which provides for an exception in regard to operating restrictions which were already established at the time when the Directive entered into force.

35 In that regard, the Belgian Government adds that the Royal Decree of 14 April 2002 formed part of the 'established policies' and 'operating restrictions already in force' referred to by Resolution A 33-7 adopted by the 33rd Assembly of the International Civil Aviation Organisation ('the ICAO') in October 2001, which contains the 'Consolidated Statement of Continuing ICAO Policies and Practices Related to Environmental Protection', and by Article 7 of the Directive respectively. In order to limit night-time noise pollution at Brussels Airport, the Belgian Council of Ministers adopted 'the Airport Agreement' on 11 February 2000 and set up an ad hoc working group responsible for drafting a set of draft regulations. Since those provisions form part of an established policy which was established and at least decided upon by the national authorities during 2000, that is to say, before the entry into force of the Directive, they should benefit from the exception to the application of less restrictive assessment rules implemented by the Directive.

36 It is common ground that Regulation No 925-1999, in force from 4 May 2000, concerned, inter alia, the adoption of protective measures aimed at preventing deterioration of the general noise situation around Community airports, as well as reducing fuel burn and gaseous emissions. Those measures consisted in the imposition in all the Member States of operating restrictions on recertificated civil subsonic jet aeroplanes by taking their engine by-pass ratio as a guide.

37 The Directive also pursues the objectives of avoiding an increase in noise pollution and the protection of the environment through the introduction of operating restrictions. Such restrictions are not, however, linked to the engine by-pass ratio of aeroplanes, but are established on the basis of a balanced approach to noise management in each airport covered by the Directive. The advantage of that approach lies in the fact that operating restrictions of the same kind are applied in airports with comparable noise problems.

38 It is clear from recital (10) in the preamble to the Directive that the balanced approach constitutes a policy approach to address aeroplane noise, including international guidance for the introduction of operating restrictions on an airport-by-airport basis. The 'balanced approach' to aircraft noise management, defined in Resolution A 33-7, adopted by the 33rd ICAO Assembly, comprises four principal elements and requires careful assessment of all different options to mitigate noise, including reduction of aeroplane noise at source, land-use planning and management measures, noise abatement operational procedures and operating restrictions, without prejudice to relevant legal obligations, existing agreements, current laws and established policies.

39 It is also clear from recital (18) in the preamble to the Directive that, in those circumstances, the Community legislature considered it necessary, in order to respect the established rights of the economic operators concerned, to allow for the continuation of existing airport-specific noise management measures. For that reason, under Article 7 of the Directive, the rules to be followed where a decision on operating restrictions is being considered, set out in Article 5 of the Directive, are not applicable to already existing operating restrictions.

40 It is true that the wording of Article 7(a) of the Directive refers to operating restrictions which were already established on the date of entry into force of the Directive. However, it does not follow that the environmental protection objectives set out in the Airport Agreement adopted by the Belgian Council of Ministers on 11 February 2000, which were achieved in stages with the adoption of various specific decisions, can be regarded as operating restrictions for the purposes of Article 7.

41 The title of Article 7 itself indicates that that provision relates to already existing operating restrictions. Although it is apparent from the Airport Agreement that the Council of Ministers had decided to act in order to limit night-time noise pollution at airports, that agreement did not introduce specific compulsory operating restrictions for the economic operators concerned.

42 In support of its arguments, the Belgian Government refers to the text of Article 7 as it was worded in the draft directive submitted by the Commission, according to which Article 5 of the Directive was not to apply to operating restrictions which were already in force at the date of entry into force of the Directive. Thus, the original criterion providing that the measures had to be in force was replaced by a more flexible criterion that the measures merely had to be established. It contends that that amendment would lose all of its effectiveness if, instead of interpreting the wording of Article 7 of the Directive strictly and literally, it were necessary to interpret it as meaning that it related only to measures which were not only established, but also adopted and published.

43 That argument, however, is unconvincing.

44 Although, in relation to the draft directive submitted by the Commission, the wording of Article 7 of the Directive has been amended, that is because the legislature decided to extend the scope of the exception to the application of Article 5. Thus, the concept of 'operating restrictions that were already established on the date of entry into force of this Directive' is more consonant with the wishes of the legislature, set out in recital (18) in the preamble to the Directive, to respect the established rights of the economic operators concerned, than the concept of 'operating restrictions that were already in force' on that date, which originally appeared in the draft directive.

45 By the same token, the wording of Article 7(a) of the Directive includes within its scope, in addition to operating restrictions already in force in the Member States when the Directive entered into force, operating restrictions which were adopted and published but the actual implementation of which was deferred to a later date. In so far as the latter restrictions already imposed constraints on economic operators as to the future operation of certain types of aeroplanes even before their implementation became obligatory, the preparations undertaken by those operators in order to adapt their fleet had to be subject to an exception on the basis of the regard for established rights.

46 Since the operating restrictions imposed by the Royal Decree of 14 April 2002 had neither been adopted nor published on 28 March 2002, they were not capable of creating rights for economic operators at the date on which the Directive entered into force. It follows that they are not covered by the concept of 'operating restrictions that were already established on the date of entry into force of this Directive', within the terms of Article 7(a) thereof.

47 Finally, the Belgian Government argues that it was solely by reason of the intrinsic complexity of the Belgian legal system, involving a division of powers between the federal and regional bodies which requires compliance with a lengthy dialogue and consultation period before certain political decisions can be formalised, that it was not possible for the decision of the Council of Ministers to be formalised until 14 April 2002 with the adoption of the Royal Decree prohibiting night flights by recertificated aeroplanes.

48 It must be recalled, in that connection, that a Member State cannot plead provisions, practices or situations prevailing in its domestic legal order to justify failure to observe obligations arising under Community law (see, inter alia, Case C-212-99 Commission v Italy [2001] ECR I-4923, paragraph 34, Case C-195-02 Commission v Spain [2004] ECR I-7857, paragraph 82, and Case C-119-04 Commission v Italy [2006] ECR I-6885, paragraph 25).

49 It follows that the Royal Decree of 14 April 2002 does not come within the scope of Article 7 of the Directive.

The Royal Decree of 14 April 2002 forms part of the objective of the Community legislature

50 In the alternative, the Belgian Government argues that the Royal Decree of 14 April 2002 was adopted in order to fill a legal vacuum resulting from the repeal of Regulation No 925-1999 and that, therefore, it forms part of the objective pursued by the Community legislature. In its preamble, the Royal Decree refers to Regulation No 925-1999, first, because the discussion which took place within the Council of Ministers on 11 February 2000 referred to that regulation and, second, because the policy pursued by the Federal Government and the federal bodies was within the framework of that regulation. Given the declared intention of the Government to prohibit the use on Belgian territory of certain civil subsonic jet aeroplanes as soon as possible, the aim was to prevent economic operators assuming, because of the repeal of Regulation No 925-1999, that that type of aeroplane could be used.

51 That argument cannot be accepted.

52 First, the repeal of Regulation No 925-1999 did not create a legal vacuum, because that regulation was replaced by the Directive on the day the latter entered into force. It must be observed in that connection, as the Advocate General stated in point 82 of his Opinion, that there was nothing to prevent the Member State from adopting national legislation compatible with the provisions of the Directive.

53 Second, although it is true that, in adopting the Directive, the Community legislature was pursuing the objective of reducing noise pollution generated by aeroplanes, as with the adoption of Regulation No 925-1999, the fact remains that the implementing measures envisaged by those two pieces of legislation are radically different. Under the Directive, the reduction of noise emissions is the result of a balanced approach on noise management in each airport, whereas the provisions of Regulation No 925-1999 aim to prevent deteriorations of the overall noise impact by imposing operating restrictions on civil subsonic jet aeroplanes according to the engine by-pass ratio.

54 Third, according to Article 1(a), one of the aims of the Directive is to lay down rules for the Community to facilitate the introduction of operating restrictions in a consistent manner at airport level and for that purpose it sets out, in Article 2(d), the definition of 'marginally compliant aircraft' with respect to the standards laid down in Volume 1, Part II, Chapter 3 of Annex 16 to the Convention on International Civil Aviation, without making any reference to recertificated aircraft.

55 According to the fifth recital in its preamble, the Royal Decree of 14 April 2002 seeks to establish a regulatory framework which is harmonised at national level with respect to marginally compliant aircraft and, in order to achieve that, it introduces restrictions on night flights affecting recertificated civil subsonic jet aeroplanes, regardless of whether or not they have been modified in order to meet the standards set out in Volume 1, Part II, Chapter 3 of Annex 16 to the Convention on International Civil Aviation.

56 The Belgian Government further submits that the scope of the Royal Decree of 14 April 2002 is general and covers all the national territory, whereas Brussels National Airport, which on account of the volume of traffic is the only airport covered by the Directive, was already subject to operating restrictions. Those restrictions were established by the Ministerial Decree of 26 October 2000 approving the regulation adopted on 15 June 2000 by the Board of Directors of BIAC SA, a company governed by public law, on the introduction of an acoustic quota system during the night and determining the maximum amount of noise authorised at night at Brussels National Airport (Moniteur belge of 17 November 2000, p. 38194). Thus, that ministerial decree prohibited all takeoffs by civil subsonic jet aeroplanes departing from Brussels National Airport, and the provisions of the Royal Decree of 14 April 2002 were superimposed onto already existing rules.

57 That point of view cannot be accepted.

58 Even if the only airport in Belgium directly covered by the Directive was already subject to operating restrictions established in 2000 and imposed by a specific ministerial decree, it still does not follow that the Kingdom of Belgium, when it adopted the Royal Decree of 14 April 2002 applicable to all the airports situated in its territory regardless of the volume of traffic, could ignore the approach dictated for the establishment of noise-related operating restrictions by the Directive, which was already in force.

59 In that connection, it must be observed that, according to settled case-law, the fact that an activity referred to in a directive does not yet exist in a Member State cannot release that State from its obligation to adopt laws or regulations in order to ensure that all the provisions of the directive are properly transposed (Case C-339-87 Commission v Netherlands [1990] ECR I-851, paragraph 22; Case C-214-98 Commission v Greece [2000] ECR I-9601, paragraph 22; Case C-372-00 Commission v Ireland [2001] ECR I-10303, paragraph 11; and Case C-441-00 Commission v United Kingdom [2002] ECR I-4699, paragraph 15).

60 It follows that the Royal Decree of 14 April 2002 cannot be regarded as forming part of the Community legislature's objective.

The Royal Decree of 14 April 2002 does not seriously compromise the result prescribed by the Directive

61 In the further alternative, the Belgian Government submits that the adoption of the Royal Decree of 14 April 2002 during the period allowed to Member States for transposing the Directive not only does not seriously compromise the result which the Directive prescribes but is also likely to facilitate its implementation because it obliged airline companies to make the necessary investments to replace their fleets.

62 It must be recalled in that regard that, according to the case-law of the Court, although the Member States are not obliged to adopt measures to transpose a directive before the end of the period prescribed for transposition, it follows from the second paragraph of Article 10 EC in conjunction with the third paragraph of Article 249 EC and from that directive itself that during that period they must refrain from taking any measures liable seriously to compromise the result prescribed by that directive (see, inter alia, Case C-129-96 Inter-Environnement Wallonie [1997] ECR I-7411, paragraph 45, and Case C-138-05 Stichting Zuid-HollandseMilieufederatie [2006] ECR I-8339, paragraph 42).

63 Therefore, Member States cannot, without seriously compromising the result prescribed by the Directive, adopt measures during the period prescribed for its transposition which, while pursing the same objective, namely the reduction in the number of persons suffering from the harmful effects of aircraft noise, hinder the introduction of uniform operating restrictions throughout the Community.

64 It is common ground that, during the period prescribed for transposing the Directive, the Belgian Government adopted and published the Royal Decree of 14 April 2002. That decree was not intended to transpose the Directive, but to establish a regulatory framework harmonised at national level to reduce noise impact caused by aircraft based on the approach laid down in Regulation No 925-1999, that is, the establishment of operating restrictions on the basis of the engine by-pass ratio designed to prohibit definitively the operation of recertificated civil subsonic jet aeroplanes.

65 It follows that the adoption of the Royal Decree of 14 April 2002, which entered into force on 1 July 2003, that is, less than three months before the expiry date of the period prescribed for transposing the Directive, gave rise to unduly unfavourable treatment for certain categories of aeroplanes and had a lasting impact on the conditions of transposition and implementation of the Directive in the Community. By reason of the ban on the operation of various aeroplanes resulting from the application of that decree, the assessment of the noise impact provided for in the Directive cannot take into account the noise produced by all aeroplanes in accordance with the rules defined in Volume 1, Part II, Chapter 3 of Annex 16 to the Convention on International Civil Aviation and, therefore, the optimum improvement in noise management cannot be achieved in accordance with the provisions set out in the Directive.

66 The Belgian Government further submits that the Commission has not shown that the Royal Decree of 14 April 2002 is capable of producing such a negative result since, if it had been adopted in March 2002, the restrictions it imposes would have been accepted as existing measures when the Directive was published, covered by the derogating arrangements in Article 7. Therefore, it is unreasonable to argue that, since it was adopted one month later, the Royal Decree produces harmful effects, even though the period granted for transposing the Directive had not expired.

67 In that regard, suffice it to state, as the Commission emphasised in its reply, that that argument is entirely hypothetical and that in infringement proceedings the Court must give a ruling by taking account only of the facts of the case, excluding any suppositions. Moreover, it must be observed that the Belgian Government is presenting a hypothesis in which the Royal Decree was adopted prior to the adoption of the Directive.

68 It follows that the Royal Decree of 14 April 2002, adopted by the Kingdom of Belgium during the period prescribed for the transposition of the Directive, is liable seriously to compromise the result prescribed by the Directive.

69 In those circumstances, it must be held that the action brought by the Commission is well founded.

70 Accordingly, it must be held that, by adopting the Royal Decree of 14 April 2002, the Kingdom of Belgium has failed to fulfil its obligations under the Directive and under the second paragraph of Article 10 EC, read in conjunction with the third paragraph of Article 249 EC.

Costs

71 Under Article 69(2) of the Rules of Procedure, the unsuccessful party is to be ordered to pay the costs if they have been applied for in the successful party's pleadings. Since the Commission has applied for costs and the Kingdom of Belgium has been unsuccessful, the latter must be ordered to pay the costs.

On those grounds, the Court (Third Chamber) hereby:

1. Declares that, by adopting the Royal Decree of 14 April 2002 regulating night flights of certain types of civil subsonic jet aeroplanes, the Kingdom of Belgium has failed to fulfil its obligations under Directive 2002-30-EC of the European Parliament and of the Council of 26 March 2002 on the establishment of rules and procedures with regard to the introduction of noise-related operating restrictions at Community airports and under the second paragraph of Article 10 EC, read in conjunction with the third paragraph of Article 249 EC;

2. Orders the Kingdom of Belgium to pay the costs.