CELEX: 62020CJ0413
Language: en
Date: 2021-11-18
Title: Judgment of the Court (Ninth Chamber) of 18 November 2021.#État belge v LO and Others.#Request for a preliminary ruling from the Tribunal de première instance francophone de Bruxelles.#Reference for a preliminary ruling – Air transport – Regulation (EU) No 1178/2011 – Technical requirements and administrative procedures related to civil aviation aircrew – Points 9 and 10 of Subpart A of Appendix 3 to Annex I – Training course for the issue of a commercial pilot licence – Flying training – Instrument ground time – Calculation – Simulator training – Skill test – Principle of legal certainty – Temporal limitation of the effects of a preliminary ruling.#Case C-413/20.

JUDGMENT OF THE COURT (Ninth Chamber)
   18 November 2021 (
         *1
      )
   (Reference for a preliminary ruling – Air transport – Regulation (EU) No 1178/2011 – Technical requirements and administrative procedures related to civil aviation aircrew – Points 9 and 10 of Subpart A of Appendix 3 to Annex I – Training course for the issue of a commercial pilot licence – Flying training – Instrument ground time – Calculation – Simulator training – Skill test – Principle of legal certainty – Temporal limitation of the effects of a preliminary ruling)
   In Case C‑413/20,
   REQUEST for a preliminary ruling under Article 267 TFEU from the tribunal de première instance francophone de Bruxelles (Brussels Court of First Instance (French-speaking), Belgium), made by decision of 12 February 2020, received at the Court on 2 September 2020, in the proceedings
   
      État belge
   
   v
   
      LO,
   
   
      OG,
   
   
      SH,
   
   
      MB,
   
   
      JD,
   
   
      OP,
   
   
      Bluetail Flight School SA (BFS),
   
   THE COURT (Ninth Chamber),
   composed of K. Jürimäe (Rapporteur), President of the Third Chamber, acting as President of the Ninth Chamber, S. Rodin and N. Piçarra, Judges,
   Advocate General: A. Rantos,
   Registrar: A. Calot Escobar,
   having regard to the written procedure,
   after considering the observations submitted on behalf of:
   
            –
         
         
            LO, OG, SH, MB, JD and OP, by S. Golinvaux, T. Godener and P. Frühling, avocats,
         
      
            –
         
         
            Bluetail Flight School SA (BFS), by J. d’Oultremont, avocat,
         
      
            –
         
         
            the Belgian Government, by M. Van Regemorter, L. Van den Broeck and C. Pochet, acting as Agents, and by L. Delmotte and B. Van Hyfte, advocaten,
         
      
            –
         
         
            the Austrian Government, by J. Schmoll and G. Kunnert, acting as Agents,
         
      
            –
         
         
            the European Commission, by B. Sasinowska, C. Vrignon and W. Mölls, acting as Agents,
         
      having decided, after hearing the Advocate General, to proceed to judgment without an Opinion,
   gives the following
   
      Judgment
   
   
            1
         
         
            This request for a preliminary ruling concerns the interpretation of points 9 and 10 of Subpart A of Appendix 3 to Annex I to Commission Regulation (EU) No 1178/2011 of 3 November 2011 laying down technical requirements and administrative procedures related to civil aviation aircrew pursuant to Regulation (EC) No 216/2008 of the European Parliament and of the Council (OJ 2011 L 311, p. 1), as amended by Commission Regulation (EU) 2018/1119 of 31 July 2018 (OJ 2018 L 204, p. 13), (‘Regulation No 1178/2011’), and of the principle of legal certainty.
         
      
            2
         
         
            The request has been made in proceedings between État belge (the Belgian State), on the one hand, and LO, OG, SH, MB, JD and OP (‘the former students’) and Bluetail Flight School SA (‘BFS’), on the other, concerning the former students’ right to be issued with a commercial pilot licence.
         
      
      Legal context
   
   
      
         European Union law
      
   
   
            3
         
         
            Recital 1 of Regulation No 1178/2011 states:
            ‘Regulation (EC) No 216/2008 [of the European Parliament and of the Council of 20 February 2008 on common rules in the field of civil aviation and establishing a European Aviation Safety Agency, and repealing Council Directive 91/670/EEC, Regulation (EC) No 1592/2002 and Directive 2004/36/EC (OJ 2008 L 79, p. 1)] aims at establishing and maintaining a high uniform level of civil aviation safety in Europe. That Regulation provides for the means of achieving that objective and other objectives in the field of civil aviation safety.’
         
      
            4
         
         
            As set out in Article 1 of Regulation No 1178/2011:
            ‘This Regulation lays down detailed rules for:
            
                     (1)
                  
                  
                     different ratings for pilots’ licences, the conditions for issuing, maintaining, amending, limiting, suspending or revoking licences …;
                  
               …’
         
      
            5
         
         
            Article 2 of that regulation, headed ‘Definitions’, is worded as follows:
            ‘For the purposes of this Regulation, the following definitions shall apply:
            
                     (1)
                  
                  
                     “Part-FCL licence” means a flight crew licence which complies with the requirements of Annex I;
                  
               …
            
                     (16)
                  
                  
                     “Approved training organisation (ATO)” means an organisation which is entitled to provide training to pilots on the basis of an approval issued in accordance with the first subparagraph of Article 10a(1);
                  
               …’
         
      
            6
         
         
            Article 3(1) of that regulation provides:
            ‘Without prejudice to Article 8 of this Regulation, pilots of aircraft referred to in Article 4(1)(b) and (c) and Article 4(5) of Regulation (EC) No 216/2008 shall comply with the technical requirements and administrative procedures laid down in Annex I and Annex IV to this Regulation.’
         
      
            7
         
         
            Annex I to Regulation No 1178/2011, headed ‘Part-FCL’, contains, inter alia, Part A, headed ‘General requirements’, which comprises points FCL.001 to FCL.070.
         
      
            8
         
         
            Under the heading ‘Scope’, point FCL.005 of that annex states:
            ‘This Part establishes the requirements for the issue of pilot licences and associated ratings and certificates and the conditions of their validity and use.’
         
      
            9
         
         
            Point FCL.010 of that annex, headed ‘Definitions’, provides:
            ‘For the purposes of this Annex (Part-FCL), the following definitions shall apply:
            …
            “Full Flight Simulator” (FFS) means a full size replica of a specific type or make, model and series aircraft flight deck, including the assemblage of all equipment and computer programmes necessary to represent the aircraft in ground and flight operations, a visual system providing an out-of-the-flight deck view, and a force cueing motion system.
            …
            “Flight Training Device” (FTD) means a full size replica of a specific aircraft type’s instruments, equipment, panels and controls in an open flight deck area or an enclosed aircraft flight deck, including the assemblage of equipment and computer software programmes necessary to represent the aircraft in ground and flight conditions to the extent of the systems installed in the device. It does not require a force cueing motion or visual system, except in the case of helicopter FTD levels 2 and 3, where visual systems are required.
            “Flight and Navigation Procedures Trainer” (FNPT) means a training device which represents the flight deck or cockpit environment, including the assemblage of equipment and computer programmes necessary to represent an aircraft type or class in flight operations to the extent that the systems appear to function as in an aircraft.
            …
            “Instrument flight time” means the time during which a pilot is controlling an aircraft in flight solely by reference to instruments.
            “Instrument ground time” means the time during which a pilot is receiving instruction in simulated instrument flight, in flight simulation training devices (FSTD).
            “Instrument time” means instrument flight time or instrument ground time.
            …
            “Multi-crew cooperation” (MCC) means the functioning of the flight crew as a team of cooperating members led by the pilot-in-command.
            …
            “Pilot-in-command” (PIC) means the pilot designated as being in command and charged with the safe conduct of the flight.
            …
            “Skill test” means the demonstration of skill for a licence or rating issue, including such oral examination as may be required.
            …
            “Student pilot-in-command” (SPIC) means a student pilot acting as pilot-in-command on a flight with an instructor where the latter will only observe the student pilot and shall not influence or control the flight of the aircraft.
            …’
         
      
            10
         
         
            Point FCL.030 of that annex, headed ‘Practical skill test’, reads as follows:
            
                     ‘(a)
                  
                  
                     Before a skill test for the issue of a licence, rating or certificate is taken, the applicant shall have passed the required theoretical knowledge examination, except in the case of applicants undergoing a course of integrated flying training.
                     In any case, the theoretical knowledge instruction shall always have been completed before the skill tests are taken.
                  
               
                     (b)
                  
                  
                     Except for the issue of an airline transport pilot licence, the applicant for a skill test shall be recommended for the test by the organisation/person responsible for the training, once the training is completed. The training records shall be made available to the examiner.’
                  
               
      
            11
         
         
            Appendix 3 to Annex I to Regulation No 1178/2011 describes, as stated in point 1 thereof, ‘the requirements for the different types of training courses for the issue of a CPL and an ATPL [airline transport pilot licence], with and without an IR [instrument rating]’.
         
      
            12
         
         
            Subpart A of that appendix, headed ‘ATP integrated courses – Aeroplanes’, contains the following passage:
            ‘GENERAL
            …
            
                     4.
                  
                  
                     The course shall comprise:
                     
                              (a)
                           
                           
                              theoretical knowledge instruction to ATPL(A) knowledge level;
                           
                        
                              (b)
                           
                           
                              visual and instrument flying training; and
                           
                        
                              (c)
                           
                           
                              training in MCC for the operation of multi-pilot aeroplanes.
                           
                        …
                     FLYING TRAINING
                  
               
                     9.
                  
                  
                     The flying training, not including type rating training, shall comprise a total of at least 195 hours, to include all progress tests, of which up to 55 hours for the entire course may be instrument ground time. Within the total of 195 hours, applicants shall complete at least:
                     
                              (a)
                           
                           
                              95 hours of dual instruction, of which up to 55 hours may be instrument ground time;
                           
                        
                              (b)
                           
                           
                              70 hours as PIC, including VFR [Visual Flight Rules] flight and instrument flight time as student pilot-in-command (SPIC). The instrument flight time as SPIC shall only be counted as PIC flight time up to a maximum of 20 hours;
                           
                        
                              (c)
                           
                           
                              50 hours of cross-country flight as PIC, including a VFR cross-country flight of at least 540 km (300 NM), in the course of which full stop landings at two aerodromes different from the aerodrome of departure shall be made;
                           
                        
                              (d)
                           
                           
                              5 hours flight time shall be completed at night, comprising 3 hours of dual instruction, which will include at least 1 hour of cross-country navigation and 5 solo take-offs and 5 solo full stop landings; and
                           
                        
                              (e)
                           
                           
                              115 hours of instrument time comprising, at least:
                              
                                       (1)
                                    
                                    
                                       20 hours as SPIC;
                                    
                                 
                                       (2)
                                    
                                    
                                       15 hours MCC, for which an FFS or FNPT II may be used;
                                    
                                 
                                       (3)
                                    
                                    
                                       50 hours of instrument flight instruction, of which up to:
                                       
                                                (i)
                                             
                                             
                                                25 hours may be instrument ground time in a FNPT I; or
                                             
                                          
                                                (ii)
                                             
                                             
                                                40 hours may be instrument ground time in a FNPT II, FTD 2 or FFS, of which up to 10 hours may be conducted in an FNPT I.
                                             
                                          An applicant holding a course completion certificate for the Basic Instrument Flight Module shall be credited with up to 10 hours towards the required instrument instruction time. Hours done in a BITD [Basic Instrument Training Device] shall not be credited.
                                    
                                 
                        
                              (f)
                           
                           
                              5 hours to be carried out in an aeroplane certificated for the carriage of at least 4 persons that has a variable pitch propeller and retractable landing gear.
                           
                        SKILL TEST
                  
               
                     10.
                  
                  
                     Upon completion of the related flying training, the applicant shall take the CPL(A) skill test on either a single-engine or a multi-engine aeroplane and the IR skill test on a multi-engine aeroplane.’
                  
               
      
      
         Belgian law
      
   
   
            13
         
         
            Article 1 of the Royal Decree of 25 October 2013 implementing [Regulation No 1178/2011] (Moniteur belge of 16 December 2013, p. 98879) states:
            ‘For the purposes of this decree, the following definitions shall apply:
            …
            12° DGTA: Directorate-General for Air Transport of the [FPS (Federal Public Service) Mobility and Transport];
            …’
         
      
            14
         
         
            As set out in Article 4 of that royal decree:
            ‘The DGTA is designated as the competent authority as referred to in Article 11b of [Regulation No 1178/2011].’
         
      
            15
         
         
            Article 5 of that royal decree provides:
            ‘The DGTA is designated as the competent authority as referred to in FCL.001 of Annex I to [Regulation No 1178/2011].’
         
      
            16
         
         
            According to the explanations provided by the referring court in the request for a preliminary ruling, the DGTA has no legal personality separate from the Belgian State.
         
      
      The dispute in the main proceedings and the questions referred for a preliminary ruling
   
   
            17
         
         
            On an unspecified date, the former students began flying training with the BFS, a training body that is authorised by the DGTA and whose 2014 and 2016 training programmes were approved by the DGTA. That training was designed to enable the former students to obtain a commercial pilot licence for aeroplanes, known as the CPL(A).
         
      
            18
         
         
            At the end of 2018, after passing the skill test referred to in point 10 of Subpart A of Appendix 3 to Annex I to Regulation No 1178/2011, the former students, with the exception of OP, applied to the DGTA for a CPL(A) licence.
         
      
            19
         
         
            By decisions of 15 January 2019, the DGTA refused to issue the former students with the licence applied for. After the Conseil d’État (Council of State, Belgium) had issued an interim order suspending those decisions and they were withdrawn by the DGTA, the latter, on 22 February 2019, issued the former students, with the exception of OP, with new refusal decisions.
         
      
            20
         
         
            In the decisions of 22 February 2019, the DGTA states that the number of hours of instrument time completed by each of the former students was less than the 115 hours required by point 9(e) of Subpart A of Appendix 3 to Annex I to Regulation No 1178/2011. According to the DGTA, hours completed on a FNPT II in excess of the maximum number of 55 hours referred to in the first sentence of point 9 cannot be taken into consideration in the calculation of the minimum 115 hours of instrument time required by point 9(e).
         
      
            21
         
         
            Hearing an application for interim measures brought by the former students, with the exception of OP, the President of the tribunal de première instance francophone de Bruxelles (Brussels Court of First Instance (French-Speaking), Belgium) ordered the DGTA, on 18 April 2019, to issue them with a CPL(A) licence. That order, which was complied with by the DGTA, was upheld on 8 August 2019 by the cour d’appel de Bruxelles (Court of Appeal, Brussels, Belgium), which found, inter alia, that the DGTA had relied on a new, fluctuating interpretation of the legislation at issue.
         
      
            22
         
         
            In the meantime, on 31 May 2019, the Belgian State brought proceedings against the former students, with the exception of OP, and the BFS before the tribunal de première instance francophone de Bruxelles (Brussels Court of First Instance (French-Speaking)), the referring court, inter alia for an order that they return the CPL(A) licences that had been issued to them pursuant to the order of 18 April 2019. The DGTA subsequently issued OP with a provisional CPL(A) licence and OP was therefore also summoned to appear before that court for the same purposes by way of summons dated 20 December 2019.
         
      
            23
         
         
            According to the Belgian State, the former students must complete their training by undergoing hours of instrument instruction in an aircraft before sitting the skill test again. The former students and the BFS take the opposite view.
         
      
            24
         
         
            In those circumstances the tribunal de première instance francophone de Bruxelles (Brussels Court of First Instance (French-Speaking)) decided to stay the proceedings and to refer the following questions to the Court of Justice for a preliminary ruling:
            
                     ‘(1)
                  
                  
                     Does point 9 of Subpart A of Appendix 3 to Annex I to [Regulation No 1178/2011] allow hours of training completed on an FNPT II flight simulator (instrument ground time) in excess of the number of 15 hours of MCC referred to in point 9(e)(2) and in excess of the maximum of 40 hours of instrument flight instruction in an FNPT II, referred to in point 9(e)(3)(ii), that is to say, more than 55 hours of instrument ground time, to be taken into account for the purpose of calculating the 115 hours of instrument time referred to in point 9(e)?
                  
               
                     (2)
                  
                  
                     Does the answer to the first question vary depending on whether the hours completed in excess of the 15 hours and 40 hours referred to above consist of hours of MCC or of a different type of simulator training?
                  
               
                     (3)
                  
                  
                     If the answer to the two preceding questions is in the negative, does point 10 of [Subpart A of] Appendix 3 to Annex I to that regulation permit the CPL(A) licence to be granted after the candidate pilots have completed their training by a sufficient number of hours in an aircraft, without the skill test relating to instrument flight being retaken?
                  
               
                     (4)
                  
                  
                     If the answer to the three preceding questions is in the negative, does the general principle of legal certainty require that the interpretation of the legal rule in question provided by the Court of Justice be limited in time, so that, for example, it will apply only to candidate pilots who request the grant of a CPL(A) licence, or even to those who have commenced their training in order to obtain such a licence, after the date of the judgment of the Court of Justice?’
                  
               
      
      Consideration of the questions referred
   
   
      
         The first and second questions
      
   
   
            25
         
         
            By its first and second questions, which it is appropriate to examine together, the referring court seeks, in essence, to ascertain whether point 9(e) of Subpart A of Appendix 3 to Annex I to Regulation No 1178/2011 must be interpreted as meaning that, in respect of the 115 hours of instrument time referred to in that provision, it is possible to count more than 55 hours of instrument ground time, in excess of the 40 hours of instrument flight instruction and 15 hours of MCC that may be completed on the ground.
         
      
            26
         
         
            For the purpose of interpreting a provision of EU law, it is necessary to consider not only its wording but also the context in which it occurs and the objectives pursued by the rules of which it is part (judgment of 12 October 2017, Tigers, C‑156/16, EU:C:2017:754, paragraph 21 and the case-law cited).
         
      
            27
         
         
            Subpart A of Appendix 3 to Annex I to Regulation No 1178/2011 sets out the list of training courses necessary for the issue of a CPL(A) licence and an IR. Pursuant to point 4 of Subpart A of Appendix 3 to Annex I to that regulation, those courses are to comprise theoretical knowledge instruction and practical training, referred to as ‘flying training’.
         
      
            28
         
         
            The content of the flying training is governed by point 9 of Subpart A of Appendix 3 to Annex I to that regulation.
         
      
            29
         
         
            Pursuant to that provision, the flying training is to comprise ‘a total of at least 195 hours, including all progress tests, of which up to 55 hours for the entire course may be instrument ground time’. That provision then lists, under (a) to (f), the duration and nature of the courses which applicants must complete as a minimum (‘at least’) within those 195 hours.
         
      
            30
         
         
            In that connection, letter (e) contains a requirement to complete at least ‘115 hours of instrument time’.
         
      
            31
         
         
            In accordance with point 9(e)(1)-(3) of Subpart A of Appendix 3 to Annex I to Regulation No 1178/2011, those 115 hours of instrument time are to comprise, in turn, ‘at least’, first, 20 hours as a student pilot-in-command, secondly, 15 hours of multi-crew cooperation, for which a FFS or FNPT II may be used, and, thirdly, 50 hours of instrument flight instruction, of which up to 25 hours may be instrument ground time in a FNPT I or 40 hours may be instrument ground time in a FNPT II, FTD 2 or FFS (of which up to 10 hours may be conducted in a FNPT I).
         
      
            32
         
         
            In the first place, as regards the literal interpretation of point 9(e) of Subpart A of Appendix 3 to Annex I to Regulation No 1178/2011, it should be pointed out that the use of the expression ‘at least’ indicates that both the 115 hours of instrument time, on the one hand, and the 20 hours as a student pilot-in-command, the 15 hours of multi-crew cooperation and the 50 hours of instrument flight instruction, on the other, constitute minimum requirements. The fact that the sum of those 20, 15 and 50 hours is less than the required 115 hours of instrument time supports the view that those 20, 15 and 50 hours reflect minimum requirements, which means that they must be supplemented by additional training hours in order to reach the required 115 hours of instrument time.
         
      
            33
         
         
            It is also apparent from the wording of that provision, read in the light of the definition of the concept of ‘instrument time’ in point FCL.010 of Annex I to Regulation No 1178/2011, that the required 115 hours of instrument time may comprise both ‘instrument flight time’, during which a pilot is controlling an aircraft in flight solely by reference to instruments, and ‘instrument ground time’, during which a pilot is receiving instruction in simulated instrument flight, in a flight simulation training device, whether it be a FFS, FNPT or FTD.
         
      
            34
         
         
            In that connection, it follows from the actual wording of point 9(e)(2) of Subpart A of Appendix 3 to Annex I to Regulation No 1178/2011 that the 15 hours of multi-crew cooperation may be completed entirely on the ground in an FFS or FNPT II. In the light of that wording, the considerations in paragraph 32 above and the absence of any contrary indication in that provision or in that regulation, it should be held that not only may an applicant complete more than 15 hours of multi-crew cooperation, but he or she may also, in principle, complete the excess hours on the ground. It is therefore possible, in principle, to count more than 15 hours of instrument ground time.
         
      
            35
         
         
            By contrast, as regards instrument flight instruction, it is clear from the wording of point 9(e)(3) of Subpart A of Appendix 3 to Annex I to Regulation No 1178/2011 and, more specifically, from the use of the words ‘up to’, that, while applicants must complete at least 50 hours of instrument flight instruction, they cannot complete more than 40 of those hours on the ground in a FNPT II, FTD 2 or FFS. It follows that hours of instrument flight instruction completed on the ground in excess of those 40 hours cannot be taken into account for the purpose of calculating the required training hours.
         
      
            36
         
         
            In the second place, as regards the context of the provision at point 9(e)(2) and (3) of Subpart A of Appendix 3 to Annex I to Regulation No 1178/2011, it should be borne in mind that, as pointed out in paragraph 29 above, point 9, of which that provision forms part, states that flying training is to comprise ‘a total of at least 195 hours … of which up to 55 hours for the entire course may be instrument ground time’.
         
      
            37
         
         
            It follows clearly that an applicant cannot count more than 55 hours of instrument ground time for the purpose of completing his or her flying training, taking all training hours together. In other words, any hours of instrument ground time completed in addition to those 55 hours cannot be taken into account in calculating the training hours completed in order to reach the required total of 195 hours.
         
      
            38
         
         
            Thus, point 9(e)(2) and (3) of Subpart A of Appendix 3 to Annex I to Regulation No 1178/2011 cannot, without disregarding the scheme and intrinsic coherence of point 9, be interpreted as allowing any hours of instrument ground time in excess of 55 hours to be taken into account.
         
      
            39
         
         
            Consequently, where applicants have completed 40 hours of instrument ground time, as point 9(e)(3)(ii) of Subpart A of Appendix 3 to Annex I to Regulation No 1178/2011 allows them to do, they can count, at most, only 15 hours of multi-crew cooperation completed on the ground under point 9(e)(2).
         
      
            40
         
         
            By contrast, an applicant who has completed fewer than 40 hours of instrument ground time may claim more than 15 hours of multi-crew cooperation completed on the ground provided that his or her training respects, in particular, the maximum limit of 55 hours of instrument ground time for the entire course.
         
      
            41
         
         
            Contrary to the arguments put forward by the former students and by the BFS in their written observations, this interpretation of point 9(e)(2) of Subpart A of Appendix 3 to Annex I to Regulation No 1178/2011 is not such as to transform the minimum requirement set out therein into a maximum limit.
         
      
            42
         
         
            In the third place, the interpretation that an applicant cannot count more than 55 hours of instrument ground time under point 9(e) of Subpart A of Appendix 3 to Annex I to Regulation No 1178/2011 is supported by the objective pursued by that regulation.
         
      
            43
         
         
            That regulation, as is apparent from recital 1 thereof, forms part of a body of rules aimed at ensuring civil aviation safety.
         
      
            44
         
         
            That objective dictates that every applicant should gain real flying experience by completing a significant number of training hours under real conditions in an aircraft. While ground training is supplementary to flying training, it cannot replace it.
         
      
            45
         
         
            In the light of all of the foregoing considerations, the answer to the first and second questions is that point 9(e) of Subpart A of Appendix 3 to Annex I to Regulation No 1178/2011 must be interpreted as meaning that, in calculating the 115 hours of instrument time referred to in that provision, it is not possible to count more than 55 hours of instrument ground time.
         
      
      
         The third question
      
   
   
            46
         
         
            By its third question, the referring court seeks, in essence, to ascertain whether point 10 of Subpart A of Appendix 3 to Annex I to Regulation No 1178/2011 must be interpreted as meaning that, where an applicant has sat the skill test before completing all of the required training hours, the CPL(A) licence may be granted to the applicant once he or she has completed his or her training without the applicant having to sit the related skill test again.
         
      
            47
         
         
            As set out in point 10 of Subpart A of Appendix 3 to Annex I to Regulation No 1178/2011, ‘upon completion of the related flying training, the applicant shall take the … skill test …’.
         
      
            48
         
         
            The wording of that provision, whether in the German (‘nach Abschluss’), Spanish (‘tras la finalizacion’), French (‘à l’issue’), Italian (‘in seguito al
               completamento’) or English (‘upon completion’) versions, thus expressly provides that it is only after completing the flying training that an applicant may take the skill test.
         
      
            49
         
         
            No different interpretation can be inferred from the definition of skill test, as set out in point FCL.010 of Annex I to Regulation No 1178/2011, or from the general requirements relating to that test, as set out in point FCL.030 of that annex, which do not contain any indication from which it could clearly be inferred that the skill test may take place before all hours of flying training have been completed.
         
      
            50
         
         
            It follows that an applicant who has sat the skill test before completing the required number of training hours must not only complete his or her training but also retake the related skill test at the end of the completed training.
         
      
            51
         
         
            In the light of all of the foregoing considerations, the answer to the third question is that point 10 of Subpart A of Appendix 3 to Annex I to Regulation No 1178/2011 must be interpreted as meaning that, where an applicant has sat the skill test before completing all of the required training hours, the CPL(A) licence may be granted to him or her only once he or she has completed the training and sat the related skill test again.
         
      
      Limitation of the temporal effects of the present judgment
   
   
            52
         
         
            In view of the answers given to the first, second and third questions, it is necessary to rule on the issues raised by the referring court in its fourth question as to the possibility of limiting the temporal effects of the present judgment.
         
      
            53
         
         
            It should be recalled in this connection that, in accordance with settled case-law, the interpretation which, in the exercise of the jurisdiction conferred upon it by Article 267 TFEU, the Court gives to a rule of EU law clarifies and defines the meaning and scope of that rule as it must be, or ought to have been, understood and applied from the time at which it entered into force. It follows that the rule as thus interpreted may and must be applied by the courts to legal relationships arising and established before the delivery of the judgment ruling on the request for interpretation, provided that in other respects the conditions for bringing before the courts having jurisdiction an action relating to the application of that rule are satisfied (judgment of 24 November 2020, Openbaar Ministerie (Forgery of documents), C‑510/19, EU:C:2020:953, paragraph 73 and the case-law cited).
         
      
            54
         
         
            It is only quite exceptionally that the Court may, in application of the general principle of legal certainty inherent in the EU legal order, be moved to restrict the opportunity, open to any person concerned, of relying on a provision which it has interpreted with a view to calling into question legal relationships established in good faith. Two essential criteria must be fulfilled before such a limitation can be imposed: those concerned must have acted in good faith and there must be a risk of serious difficulties (judgment of 24 November 2020, Openbaar Ministerie (Forgery of documents), C‑510/19, EU:C:2020:953, paragraph 74 and the case-law cited).
         
      
            55
         
         
            In the present case, it should be noted that neither the request for a preliminary ruling nor the observations lodged before the Court contain anything to indicate that the interpretation adopted by the Court in the present judgment would give rise to a risk of serious difficulties, since no specific indication has been given of the number of legal relationships established in good faith that may be affected by that interpretation.
         
      
            56
         
         
            That assessment is not called into question by the argument put forward by the former students and the BFS in their written observations to the effect that the answers to the first, second and third questions will necessarily and automatically lead to the retroactive revocation of all CPL(A) licences granted in all Member States following deficient training.
         
      
            57
         
         
            Although that argument appears to be based on the premiss that CPL(A) licences granted by decisions that have become final will have to be revoked, it should be borne in mind, without prejudice to the case-law cited in paragraph 53 above, that, in accordance with the principle of legal certainty, EU law does not require that administrative bodies be placed under an obligation, in principle, to reopen an administrative decision which has become final upon expiry of reasonable periods for legal remedies or by the exhaustion of remedies. Compliance with that principle prevents administrative acts which produce legal effects from being called into question indefinitely (see, to that effect, judgments of 13 January 2004, Kühne & Heitz, C‑453/00, EU:C:2004:17, paragraphs 22 and 24, and of 14 May 2020, Országos Idegenrendézeti Főigazgatóság Dél-alföldi Regionális Igazgatóság, C‑924/19 PPU and C‑925/19 PPU, EU:C:2020:367, paragraph 186 and the case-law cited).
         
      
            58
         
         
            In those circumstances, there is nothing in the present case to give grounds for derogating from the principle that a ruling on interpretation produces its effects on the date on which the rule interpreted entered into force.
         
      
            59
         
         
            In the light of all of the above considerations, it is not appropriate to limit the temporal effects of the present judgment.
         
      
            60
         
         
            Furthermore, in order to give the referring court a full answer, it is necessary to add that the full effectiveness of EU law and effective protection of the rights which individuals derive from it may, where appropriate, be ensured by the principle of State liability for loss or damage caused to individuals as a result of breaches of EU law for which the State can be held responsible, as that principle is inherent in the system of the Treaties on which the European Union is based (see, to that effect, judgments of 5 March 1996, Brasserie du Pêcheur and Factortame, C‑46/93 and C‑48/93, EU:C:1996:79, paragraphs 20, 39 and 52, and of 19 December 2019, Deutsche Umwelthilfe, C‑752/18, EU:C:2019:1114, paragraph 54).
         
      
      Costs
   
   
            61
         
         
            Since these proceedings are, for the parties to the main proceedings, a step in the action pending before the national court, the decision on costs is a matter for that court. Costs incurred in submitting observations to the Court, other than the costs of those parties, are not recoverable.
         
       
         
            On those grounds, the Court (Ninth Chamber) hereby rules:
         
       
         
            
                     
                        1.
                     
                  
                  
                     
                        Point 9(e) of Subpart A of Appendix 3 to Annex I to Commission Regulation (EU) No 1178/2011 of 3 November 2011 laying down technical requirements and administrative procedures related to civil aviation aircrew pursuant to Regulation (EC) No 216/2008 of the European Parliament and of the Council, as amended by Commission Regulation (EU) 2018/1119 of 31 July 2018, must be interpreted as meaning that, in calculating the 115 hours of instrument time referred to in that provision, it is not possible to count more than 55 hours of instrument ground time.
                     
                  
               
       
         
            
                     
                        2.
                     
                  
                  
                     
                        Point 10 of Subpart A of Appendix 3 to Annex I to Regulation No 1178/2011, as amended by Regulation 2018/1119, must be interpreted as meaning that, where an applicant has sat the skill test before completing all of the required training hours, the CPL(A) licence may be granted to him or her only once he or she has completed the training and sat the related skill test again.
                     
                  
               
       
            
               
                  [Signatures]
               
            
         (
         *1
      )	Language of the case: French.