The Agency drafts regulatory material as Implementing Rules, Acceptable Means of Compliance, Guidance Material and Certification Specifications. These are available for consultation (as Terms of Reference, Notices of Proposed Amendment and Comment Response Documents). After consultation, the Implementing Rules are sent to the European Commission as Opinions.
Following publication of the Opinions, responsibility for completing the decision-making process prior to the Regulation’s publication in the Official Journal of the European Union passes onto the European Commission. The Opinions’ progress can be followed via the European Commission’s comitology website. It is advisable to search by year and for the committee dealing with these Opinions: Committee for the application of common safety rules in the field of civil aviation. As several Opinions may be negotiated in one such committee meeting, it is difficult to search by rule or title.
Once the committee has adopted the draft regulation, it is passed on to the European Parliament and Council for scrutiny. Further information and links to the documents under scrutiny can be found via the European Parliament’s Register of Documents.
The Agency is responsible for finalising the associated Acceptable Means of Compliance (AMC), Guidance Material (GM) and Certification Specifications. As these need to take into account any changes made to the Cover Regulation and Implementing Rules by the EASA Committee, European Parliament and Council, the Decisions are published on the Agency website shortly after the date when their corresponding regulation has been published in the Official Journal.
This whole sequence is illustrated in the diagram below.
The Agency also publishes a rulemaking programme, listing the tasks that are ongoing and advance planning. It is available here.
Under the Treaty the European Commission is responsible for the required implementation of Community legislation in many areas. When exercising these delegated powers it is often obliged to work with national civil servants appointed by Member States in different committees. These committees, which are a forum for discussions and the voicing of opinions, are chaired by the European Commission.
For the implementation of Regulation (EC) No 216/2008 (the Basic Regulation, BR) the European Commission is assisted by the EASA committee and the Single European Sky committee. Another committee of importance as regards aviation safety is the Air Safety committee, which is best known for being the guardian of the so called ‘Safety list’ as provided by Directive 2004/36/CE of the European Parliament and of the Council of 21 April 2004 on the safety of third-country aircraft using Community airports.
The procedures which govern the work of these committees follow the standard procedures established in Regulation (EU) 182/2011 of the European Parliament and of the Council of 16 February 2011 laying down the rules and general principles concerning mechanisms for control by Member States of the Commission’s exercise of implementing powers. It replaces Decision 1999/468/EC. This Regulation introduces a new ‘comitology’ procedure, which gives somewhat amended rights to Member States to control the way the Commission uses its delegated powers. The powers conferred to the European Parliament have been reduced slightly by the new Regulation and an Appeals Committee has been introduced in case no agreement can be reached in the committee. The latest comitology regulation can be consulted using the following link.
In principle the new comitology works as follows:
For the adoption of detailed implementing rules, the basic act may provide for the application of the examination procedure or the advisory procedure, taking into account the nature or the impact of the implementing act required.
The examination procedure applies, in particular, for the adoption of:
- Implementing acts of general scope;
- Other implementing acts relating to:
- programmes with substantial implications;
- the common agricultural and common fisheries policies;
- the environment, security and safety, or protection of the health or safety, of humans, animals or plants;
- the common commercial policy;
The advisory procedure applies, as a general rule, for the adoption of implementing acts not falling within the ambit of the aforementioned areas. However, the advisory procedure may apply for the adoption of the implementing acts referred to there in duly justified cases.
For the adoption of EASA implementing measures in the field of ATM/ANS and aerodromes only one procedure is relevant: the examination procedure.
However, to understand comitology in conjunction with the ATM and aerodromes regulatory processes it should be taken into account that the BR still refers to the old comitology process. In particular Articles 8a (Aerodromes) and 8c (Air Traffic Controllers) refer to Article 65(4) of the BR, which reads as follows:
Where reference is made to this paragraph, Article 5a (1) to (4), and Article 7 of Decision 1999/468/EC shall apply, having regard to the provisions of Article 8 thereof.
Under the old regime this was dealt with by Single Sky and EASA committees using the Regulatory Procedure with Scrutiny.
Article 8b of the BR, however, refers to Article 5(3) of Regulation (EC) No 549/2004, which reads as follows:
Where reference is made to this paragraph, Articles 5 and 7 of Decision 1999/468/EC shall apply, having regard to the provisions of Article 8 thereof.
This was dealt with by the Single Sky Committee under the Regulatory Procedure (without scrutiny).
As said before, the new Regulation 182/2011 repeals the old comitology Decision, however, its Article 12 indicates that:
- The effects of Article 5a of Decision 1999/468/EC shall be maintained for the purposes of existing basic acts making reference thereto.
So the regulatory procedure with scrutiny stays.
Article 13 indicates:
c. where the basic act makes reference to Article 5 of Decision 1999/468/EC, the examination procedure referred to in Article 5 of this Regulation shall apply ….
This means that the examination procedure replaces the old regulatory procedure. However, the examination procedure does not differ very much from the regulatory procedure. The whole procedure stays with the Single Sky committee and the EASA committee, even if no agreement is reached. It may in that case go to an appeal committee. In exceptional cases there may even be a consultation round by the Commission amongst the Member States. The Council is no longer involved. Parliament is involved only at a distance.
Procedures applicable to aerodromes rules and ATCO licensing will hardly change.
Procedures applicable to ATM/ANS rulemaking will stay within the SSC, with possibility of appeals committee; there is no Council involvement; Parliament’s involvement only on distance.
Implementing rules are Commission Regulations. They are usually composed of a short introductory regulation, colloquially known as ‘cover regulation’, and Annexes thereto, containing the technical requirements for implementation. In the EASA system, these Annexes are usually called Parts (e.g. Part-21 is an Annex to Regulation 1702/2003).
The ‘cover’ regulation is usually short (3-4 pages) and it includes:
- Considering clauses (“whereas”), explaining the principles and considerations that lead the legislator when adopting the Regulation;
- A description of the objective and scope of the regulation;
- Definitions that are used throughout the Regulation and its Annexes;
- the establishment of the applicability of its annex(es)
- Conversion and transition measures
This question relates to the English writing standards used in Community legislation. The following link gives access to the English Style Guide prepared by the European Commission’s Directorate-General for Translation. Guidance concerning the use of verbs in legislation can be found in paragraphs 6.14-6.22, as well as an explanation of the distinction between the verbs used in enacting or non-enacting terms. For more information click here . The Joint Practical Guide of the European Parliament, the Council and the Commission also gives guidance on the principles of drafting Community legislation, for more information click here
The Lisbon Treaty, the latest primary treaty at EU level, was signed on 13 December 2007 and entered into force on 1 December 2009.
The European Union has been given a single legal personality under this Treaty.
Previously, the European Community and the European Union had different statutes and did not operate the same decision-making rules. The Lisbon Treaty ended this dual system.
On practical terms, all EU legislation has the reference to the EU since 1 December 2009. Up till then, the reference was made to the European Community (EC) as only this body had legal personality.
EASA is committed to facilitating the production of good quality translations. To ensure this and, where necessary, to improve, EASA has set up a Translation Working Group in 2008. This Working Group is made up of members of the National Aviation Authorities (NAAs), the Translation Centre of the EU Bodies (CdT), as well as EASA staff members. Also, EASA in cooperation with NAAs and CdT, is developing glossaries in the different aviation domains, such as Air Operations or Air Traffic Management, to enhance the quality of translations. The Member States also contribute to this project in order to capitalise on existing material and experience.
The final responsibility for translations lies with the EU Commission. The correction of translation mistakes of the Implementing Rules follows the same formal procedure as for their adoption: 1. preparation of the proposal, 2. interservice consultation, 3. committee, 4. scrutiny of European Parliament and of European Council, and 5. adoption. For minor mistakes, the procedure may be shorter. In any case, the linguistic changes will have to be agreed by the Commission’s translation services. These linguistic services will check that no substantial change is introduced, that the term used is acceptable according to an internal translation code or that the same change is included in all linguistic versions.
Implementing Rules (IR) are binding in their entirety and used to specify a high and uniform level of safety and uniform conformity and compliance. The IRs are adopted by the European Commission in the form of Regulations.
Acceptable Means of Compliance (AMC) are non-binding. The AMC serves as a means by which the requirements contained in the Basic Regulation, and the IR, can be met. However, applicants may decide to show compliance with the requirements using other means. Both NAAs and organisations may propose alternative means of compliance. ‘Alternative Means of Compliance’ are those that propose an alternative to an existing AMC. Those Alternative Means of Compliance proposals must be accompanied by evidence of their ability to meet the intent of the IR. Use of an existing AMC gives the user the benefit of compliance with the IR.
Certification Specifications (CS) are non-binding technical standards adopted by the EASA to meet the essential requirements of the Basic Regulation. CSs are used to establish the certification basis (CB) as described below. Should an aerodrome operator not meet the recommendation of the CS, they may propose an Equivalent Level of Safety (ELOS) that demonstrates how they meet the intent of the CS. As part of an agreed CB, the CS become binding on an individual basis to the applicant.
Special Conditions (SC) are non-binding special detailed technical specifications determined by the NAA for an aerodrome if the certification specifications established by the EASA are not adequate or are inappropriate to ensure conformity of the aerodrome with the essential requirements of Annex Va to the Basic Regulation. Such inadequacy or inappropriateness may be due to:
- the design features of the aerodrome; or
- where experience in the operation of that or other aerodromes, having similar design features, has shown that safety may be compromised.
SCs, like CSs, become binding on an individual basis to the applicant as part of an agreed CB.
Guidance Material (GM) is non-binding explanatory and interpretation material on how to achieve the requirements contained in the Basic Regulation, the IRs, the AMCs and the CSs. It contains information, including examples, to assist the user in the interpretation and application of the Basic Regulation, its IRs, AMCs and the CSs.
The implementation of the Basic Regulation and its implementing regulations by Member States is subject to the European Union oversight.
According to Article 54 of the Basic Regulation - Inspections of Member States - the Agency shall assist the Commission in monitoring such implementation by conducting standardisation inspections. Upon the standardisation inspection the Agency establishes an inspection report where it addresses findings identified during the inspection and which will be sent to the Member State concerned and to the Commission. In cases of non-compliance, the Commission may initiate an infringement procedure.
Additionally, in accordance with Article 11 (2), the Commission, on its own initiative or at the request of a Member State or the Agency, may initiate a comitology procedure to decide whether a certificate issued in accordance with the Basic Regulation and its implementing regulations effectively complies with them. In case of non-compliance, the Commission shall require the issuer of a certificate to take appropriate corrective action, such as limitation or suspension of that certificate. Moreover, once the Commission issues such a decision, the obligation of mutual recognition of certificates ceases to apply to the other Member States. Once the Commission has sufficient evidence that appropriate corrective action has been taken, it will decide that mutual recognition shall be restored.
Until now no such measure has been undertaken.
The implementing rule will be available in all official languages of the European Union. They will be published in the Official Journal of the European Union and can also be searched electronically in the database EUR-LEX. And later on also on the EASA web site.
AMC, GM and CS will be available on the website of EASA in English only.
Regulation (EC) No 1592/2002 of 15 July 2002 gave responsibility to the Agency for the airworthiness and environmental certification of all aeronautical products, parts, and appliances designed, manufactured, maintained or used by persons under the regulatory oversight of EU Member States. This includes all post-certification activities, such as the approval of changes to, and repairs of, aeronautical products and their components, as well as the issuing of airworthiness directives to correct any potentially unsafe situation. Furthermore, the Agency is in charge of the oversight of EU organisations involved in the design of aeronautical products, parts and appliances as well as of non-EU organisations involved in the manufacture or maintenance of such products. In these domains the Agency has taken over the certification tasks that were under the responsibility of Member States.
Regulation (EC) No 216/2008 of the European Parliament and of the Council of 20 February 2008 that extended the scope of Community competence to air operations, flight crew licences and aircraft used by third country operators into, within or out of the Community gave the Agency additional operational responsibilities. In the field of flight crew licensing, the Agency is responsible for the approval and oversight of pilot training organisations and aero-medical centres located outside the territory of the Community; the certification of flight simulation training devices used by the training organisations it certifies, or located outside the territory of the Community, or located in the Community territory, if the member State concerned so requests. In the field of operations, the Agency was given the power to determine corrective actions and disseminate information to react without undue delay to a problem affecting the safety of air operations. Regarding third country operators, the Agency is competent for the authorisation and oversight of commercial operators; for the oversight of non-commercial operators, when they need to declare their activities; and for the authorisation of third country aircraft when they or their crews do not comply with ICAO Standards.
The Agency’ responsibilities were further extended by Regulation (EC) No 1108/2009 of the European Parliament and of the Council of 21 October 2009. The provisions of the Regulation ensure precise, uniform and binding rules for aerodrome operations and operators, air traffic management and air navigation service provision. Moreover, based on the new ATM/ANS rules the Agency will commence its standardisation inspections in ATM/ANS from 2012 onwards aiming at ensuring a uniform implementation of the common rules but also at reinforcing the national competent authorities in their important oversight role.. With the extension to ATM/ANS, the Agency is empowered to take the necessary measures related to certification and oversight of Pan-European and third country ATM/ANS organisations, as well as for the air traffic controllers’ training organisations located outside the territory of the Community.
These new competences taken on by the EASA system allow a more comprehensive and uniform approach to safety regulation across all fields of aviation and ensure that common safety rules are applied in all phases of flight, starting from the tarmac.
Regulation (EC) No 216/2008 of the European Parliament and of the Council of 20 February 2008 that extended the scope of Community competence to air operations, flight crew licences and aircraft used by third country operators into, within or out of the Community gave the Agency additional operational responsibilities. Regarding third country operators, the Agency is competent for the authorisation and oversight of commercial operators; for the oversight of non-commercial operators, when they need to declare their activities; and for the authorisation of third country aircraft when they or their crews do not comply with ICAO Standards.
With regard to third country operators the Basic Regulation specifically requires that:
- all third country operators (their aircraft, the crews and the operations) comply with the ICAO Standards. To the extent that there are no such standards, these aircraft and their operations shall comply with the Essential Requirements for airworthiness, pilot licensing and air operations as laid down in Annexes I, III and IV of the Basic Regulation, provided these requirements are not in conflict with the rights of third countries under international conventions (article 9(1));
- third country operators engaged in commercial operations receive an authorization issued by the Agency (article 9(2)); and
- third country operators engaged in non-commercial operations of complex motor-powered aircraft may be required to submit a declaration to the Agency (article 9(3)).
The detailed provisions on how to meet the above requirements of the Basic Regulation will be contained in Implementing Rules and relevant Operations Specifications and guidance material. These provisions will address the conditions, privileges and responsibilities associated with the relevant provisions of the Basic Regulation (of articles 9(1), 9(2) and 9(3)) as outlined in the above bullet points above; as well as aircraft or crew which do not hold a standard ICAO certificate of airworthiness or licence. These provisions will make use of ICAO Standards and Recommended Practices (SARPs); will not exceed any requirements for Community operators; and will contain a simple, proportionate, cost-effective and efficient process for authorizations of commercial operations. The authorization process will take account of results of the ICAO Universal Safety Oversight Audit Programme (USOAP), information from ramp inspections and other recognised information on safety aspects with regard to the operator concerned (article 9(4)). The Implementing Rules will address the process for the authorization of a commercial operator, including any conditions that would necessitate an audit.
Third country aircraft operating within the EU are subject to oversight by the Member States in accordance with Directive 2004/36/EC of the Parliament and of the Council of 21 April 2004 on the safety of third-country aircraft using Community airports, the so-called SAFA Directive. This Directive establishes a harmonised approach for the exchange of information, the execution of ramp inspections and the grounding of third-country aircraft landing at airports located in the Member States. The new Implementing Rules will incorporate the SAFA Directive while maintaining the same principles and competencies of oversight by Member States.
The Implementing Rules and supplemental material associated to third country operators are currently being developed by the Agency. These will be published for consultation in due course and will subsequently be transmitted to the European Commission as an Opinion for consideration when adopting these Implementing Rules.
The provisions for third country operators as outlined above will then become applicable from the date specified in the relevant Implementing Rules during their adoption, but not later than 8 April 2012 (article 70). Until then, the SAFA Directive and national rules of Member States continue to apply.
[3a of amending Regulation (EC) No 1108/2009] Aerodromes, including equipment, located in the territory subject to the provisions of the treaty, open to public use and which serve commercial air transport and where operations using instrument approach or departure procedures are provided, and:
- have a paved runway of 800 metres or above; or
- exclusively serve helicopters;
shall comply with this Regulation. Personnel and organisations involved in the operation of these aerodromes shall comply with this Regulation.
The Agency has concluded after a thorough review that the current Basic Regulation and Part 21 do not provide for the approval of manufacturers of raw materials. Only organisations responsible for the manufacturing and subsequent release of a 'product' and 'parts and appliances' as defined in the Basic Regulation Article 3 (c) and (d) are required to hold a POA and are therefore eligible to apply for such an approval. ED Decision 2007/012/R introduced an amendment to AMC/GM to Part-21 bringing all AMC and GM to Part 21 back into line with the EC Regulations regarding this issue and thus removing any ambiguity.
Because Agency ED Decision 2004/04/CF automatically approves minor changes and major level 2 changes to FAA STCs when made by the STC holder on his own STC, the scope of the EASA STC is considered to be the same as the scope of the original FAA STC. Therefore there is no need for an application and the STC can be applied to all models listed on the FAA STC.
A Part 145 approved organisation can only fabricate parts for its own use in accordance with approved design data (145.A.42(c)). If that data comes from the Type Certificate holder; 21A.804(a)(3) would not be applicable and those parts will not need EPA marking. If the data comes from a Supplemental Type Certificate holder, minor change approval holder or repair approval holder, the parts will have to be marked as prescribed in the applicable data which should include an EPA marking since 28/3/2004.
Article 6 of the Basic Regulation transposes into Community law the International standards of the International Civil Aviation Organisation (ICAO) related to the environmental certification of aeronautical products. The Agency is involved, together with the Commission, in the further development of such standards to ensure that they do take into account Community objectives in this field. Another important task of the Agency is to verify that the design of products comply with environmental requirements. The Agency shall therefore establish and notify the appropriate environmental requirements for each product for which environmental certification is required and issue the appropriate environmental certificates.
Such powers are established by articles 20(d) and (h) respectively of the Basic Regulation and further detailed in Part 21.A.18 "Designation of applicable environmental protection requirements and certification specifications" of Commission Regulation (EC) No 1702/2003
First of all it should be clear that the definition of "parts and appliances" (Refer to article 3 of the Basic Regulation) includes software. This is software that is installed in an aircraft and used in operating or controlling that aircraft. The rest of this response only refers to this type of software.
Secondly, "Subpart K - Parts and appliances" from Part-21 addressing installation, approval and release is applicable to this software and therefore:
- this software must be part of the design data; and
- the installation of this software in a type-certified aircraft is only accepted when it is accompanied by an EASA Form 1 and properly marked; and
- the installation is approved. (Refer to 21A.303).
In order to achieve 1) and 2), the organisation that manufactures and releases the software must meet the requirements of Subpart F or G from Part-21. This means in particular that the software must be part of the scope of that production organisation and there must be a link between the design organisation and the production organisation.
The conclusion for Field Loadable Software is therefore that this software can be delivered with an EASA Form 1 when:
- it is part of design data for which approval has been applied or granted; and.
- it is produced by, and within the scope of a production organisation that meets the requirements of Subpart F or G.
Marking of this Field Loadable Software must be in accordance with Subpart Q of Part-21. For practical reasons the marking could be on the software "container" (e.g. the CD carrying the software).
The term "critical part" or "critical component" is used in various EASA requirements, certification specifications and also in the EU-US bilateral, however it is not always defined.
A general definition does not exist. There are currently basically three different definitions:
- for rotorcraft:
CS 27-29-VLR.602(a): A critical part is a part, the failure of which could have a catastrophic effect upon the rotorcraft, and for which critical characteristics have been identified which must be controlled to ensure the required level of integrity.
- for engines, propellers and APUs:
CS-E.510(c) It is recognised that the probability of Primary Failures of certain single elements cannot be sensibly estimated in numerical terms. If the Failure of such elements is likely to result in Hazardous Engine Effects, reliance must be placed on meeting the prescribed integrity specifications of CS-E 515 (Engine critical parts) in order to support the objective of an Extremely Remote probability of Failure.
(similar for CS-P.150(c) and CS-P.160 and also for CS-APU.210(c) and CS-APU.150)
- in the EU-US bilateral:
A "Critical component" means a part identified as critical by the design approval holder during the product type validation process, or otherwise by the exporting authority. Typically, such components include parts for which a replacement time, inspection interval, or related procedure is specified in the Airworthiness Limitations section or certification maintenance requirements of the manufacturer's maintenance manual or Instructions for Continued Airworthiness.
Each of the above definitions should be used only within their own context and for their own purpose i.e. the definition of the bilateral is only relevant for the automatic acceptance of PMA parts and repair design from the US. Where the term "critical part" is not defined the dictionary meaning of "critical" should be used i.e. crucial, decisive, important, etc.
For the application of Part 21A.805 critical parts are those identified as such by the design approval holder, which for rotorcraft, engines, propellers and APUs as a minimum should be those using the definitions of the relevant CS.
Part-66 licences are required for:
- certifying the release to service of aircraft after maintenance,
- work in maintenance organisations as support staff.
Aircraft affected are those covered by the Basic Regulation. See the definition in Articles 1 and 4 of the Basic Regulation.
Release to service of piston-engine non-pressurised aircraft of 2000 Kg MTOM and below not involved in CAT do not need a Part-66 licence until 28 September 2014.
Release to service of ELA1 aeroplanes not involved in CAT do not need a Part-66 licence until 28 September 2015.
Release to service of sailplanes, balloons, and airships do not need a Part-66.
Other activities within maintenance organisations do not need Part-66 licences.
In a Part-145 approved organisation, the different categories of Part-66 licences are:
Certifying the release of aircraft after:
|A||Minor scheduled line maintenance and simple defect rectification||Line station|
|B1||Maintenance performed on aircraft structure, powerplant and mechanical and electrical systems, avionic systems requiring simple tests to prove their serviceability and no troubleshooting||Line station|
|B3||Maintenance activities on non-pressurized aeroplanes of 2T MTOM and below.||Line station|
|B2||Maintenance performed on avionic and electrical systems and electric and avionics tasks within powerplant and mechanical systems requiring only simple test and minor scheduled line maintenance and simple defect rectification||Line station|
|C||Base maintenance activities||Base|
|Support staff for:|
No, unless the basic knowledge got outside of the EU is acquired in a Part-147 training organisation approved by EASA, according to 66.B.405.
- there is a bilateral agreement between your country and the EU (the Agency is not aware of any such agreement),
- the national licence was valid within EU before the entry into force of the Regulation.
The holder of a JAR-66 licence may get a Part-66 licence by conversion only when the licence has been issued by a JAA Member State which has successfully completed the JAR-66 Review Board process. If a country is not in the list shown in this EASA document, no conversion can be made.
More details are shown on the Mutual recognition page
The holders of a JAR-66 licence issued from a country not in this list are not eligible to a conversion. They are required to demonstrate compliance with all requirements.
According to Commission Regulation (EU) No 1149/2011 of 21 October 2011 (amending Regulation (EC) No 2042/2003), the basic examinations shall be passed and experience shall be acquired within the ten years preceding the application for an aircraft basic licence.
The new regulation also states that for the purpose of time limits related to basic knowledge examinations, basic experience acquired before the Regulation applies, the origin of time shall be the date by which this Regulation applies, which is 01/08/2012 (which means until 31/07/2022).
Type ratings should be endorsed on the Part-66 licence in accordance with the list of type ratings shown in the ED Decision posted under the Aircraft type ratings for Part-66 aircraft maintenance licence page.
This list does not contain any Annex II aircraft as these are out of the scope of Basic Regulation according to subparagraph 4 of Article 4 on the maintenance field.
However, a Part-66 licence includes a page whose title is: ‘Annex to EASA Form 26’ and this page is dedicated to national privileges. When an aircraft is under the remit of the Member State, then such aircraft may be endorsed under these provisions. This is typically the case of Annex II aircraft.
The requirement of 6 months’ experience within the preceding 2 years is only for the validity of the certification authorisation. The licence itself is valid 5 years from the last renewal. Only the certification privileges are affected by the recency of experience.
To regain your experience, you may:
- either continue to accumulate maintenance experience until you gain the missing time required, or
- meet the provisions for the issue of appropriate privileges, which means:
- going to a type-training course again, including OJT as necessary, or
- when the aircraft does not require a training (aircraft belonging in Group 2 or 3), pass a type-examination, including practical assessment. See GM 66.A.20(b)2.
Neither a short period of job training session nor an aircraft type refresher training are acceptable.
Demonstration of experience should be made on similar aircraft.
Definition of ‘similar’ aircraft is provided by the AMC to 66.A.20(b)2.
No, you lose only your rights to exercise your privileges of certifying staff or support staff. The licence remains valid.