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Harmonising and standardising military airworthiness in Europe: a review of key aspects and achievements

Published online by Cambridge University Press:  26 September 2023

M. Pittini
Affiliation:
Independent Researcher
K.I. Kourousis*
Affiliation:
School of Engineering, University of Limerick, Limerick, Ireland
*
Corresponding author: K.I. Kourousis; Email: [email protected]
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Abstract

The distinct operational characteristics of military aircraft, relative to civil aircraft, have impeded the standardisation of airworthiness management practice across Europe. Standardisation has been further deterred by the intertwined certification and qualification activities specific to military aircraft. The management of airworthiness in European military aviation has undergone significant changes over the past 15 years, with the progress made attributed to the harmonisation efforts driven by the European Defence Agency (EDA). The creation of a Military Airworthiness Authorities Forum and the development of the European Military Airworthiness Requirements (EMAR) have been instrumental in creating a more homogenous regulatory landscape. The examples of five main players of the European aerospace sector, namely France, Italy, Germany, Spain and the United Kingdom, are examined from the point of view of adoption and implementation of an EMARs-based system. Their regulatory structures have revealed similarities and primary differences. The EMAR’s framework has enabled a gradual build-up of technical knowhow within the European countries who embraced this, civil-based, framework. All five countries have adopted EMARs, though through a variety of regulatory constructs. Their regulatory structures exhibit diverse practices, especially in how initial and continuing airworthiness is managed. Some countries have also elected to have more than one authority overseeing/been responsible for airworthiness. Closer collaboration between national Military Aviation Authorities (MAAs) can be achieved through standardisation at regulatory structure level. The establishment of a joint MAAs may be the next logical step in the harmonisation process, in line with EDA objective’ for a EU-wide authority with greater powers.

Type
Survey Paper
Creative Commons
Creative Common License - CCCreative Common License - BY
This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited.
Copyright
© The Author(s), 2023. Published by Cambridge University Press on behalf of Royal Aeronautical Society

Nomenclature

AAD

Autoridad de Aeronavegabilidad de la Defensa

ABDR

aircraft battle damage repair

AMC

acceptable means of compliance

BEAD

Bureau Enquêtes Accident Défense

BFD

basic framework document

CAMO

continuing airworthiness management organisation

CMA

continuous monitoring approach

CONOPS

concept of operations

CS

certification specifications

DAAA

Direzione degli Armamenti Aeronautici e per l’Aeronavigabilità

DGA

Direction Générale de l’Armement

DE&S

Defence Equipment And Support

DiGAM

Director General de Armamento y Material

DSAE

Direction de la Sécurité Aéronautique d’État

EASA

European Aviation Safety Agency

EDA

European Defence Agency

EMAR

European Military Airworthiness Requirements

EC

European Commission

EMJAO

European Military Joint Airworthiness Organisation

EU

European Union

FAA

Federal Aviation Administration

GM

guidance material

ICAO

International Civil Aviation Organisation

INTA

Instituto Nacional de Tecnica Aeroespecial

JAA

Joint Aviation Authorities

MAA

Military Aviation Authority

MACP

Military Air System Certification Process

MAWA

Military Airworthiness Authorities (Forum)

MIL-STD

military standards

MRP

Military Aviation Authority Regulatory Publications

MTC

military-type certificate

NAE NATO

airworthiness executive

NATO

North Atlantic Treaty Organisation

NMAA

National Military Aviation Authority

OCCAR

Organisation Conjointe de Cooperation en matiere d’ARmement/Organisation for Joint Armament Co-operation

PeSCo

permanent structured cooperation

RAD

Reglamento de Aeronavegabilidad de la Defensa

SARP

Standards and Recommended Practices

SMS

Safety Management System

STANAG

Standardisation Agreement

TAA

Technical Airworthiness Authority

UK

United Kingdom

US

United States (of America)

USOAP

Universal Safety Oversight Audit Program

1.0 Background

An overview of the distinct characteristics of military aviation, relative to civil aviation, is offered as a preamble of the review of the military airworthiness management in Europe. A focused discussion on the qualification and certification activity in military aviation is provided, as both are closely connected with how airworthiness is/should be managed for military aircraft. The management of airworthiness in European military aviation has undergone significant changes over the past 15 years, with the progress made attributed to the harmonisation efforts driven by the European Defence Agency (EDA). The creation of a Military Airworthiness Authorities Forum and the development of the European Military Airworthiness Requirements (EMAR) have been instrumental in creating a more homogenous regulatory landscape. Also, the need for standardisation is explained briefly, from the point of view of the national interests of the European countries, especially those who have major activity in complex industrial programs. The examples of five main players of the European aerospace sector, namely France, Italy, Germany, Spain and the United Kingdom, are examined from the point of view of adoption and implementation of an EMARs-based system. Overall, this review paper offers a critical appraisal of the military airworthiness systems in these European countries, in relation to the EMAR adoption.

1.1 Civil versus military aviation

The purpose of both civil and military aviation is to deliver a defined service (for the owner, companies, governments, etc.) using resources in a cost-effective way. From this perspective, safety, and therefore airworthiness, is a key enabler for the effectiveness of the entire process. Accidents in civil aviation can cause enormous economic losses (compensation to families of fatalities, insurance costs, reputation, etc.), while in the military aviation they lead to mission failure, collateral effects and significant economic loss (on the latter aspect it has to be considered the value of the single asset loss in relation to the fleet size). Moreover, for a civil aircraft the mission (apart from few exceptions) is identified with the flight itself (from one point to another carrying passengers or cargo), while for military assets it is the successful completion of the assigned tasks [Reference Şenol1]. In Table 1 a high-level comparison of the primary characteristics of civil and military aviation is provided. The difference between what is considered or expected as acceptable level of safety in civil and military aviation is of note (in relation to the focus of this paper, which is airworthiness). During military activities, for particular operational needs, the airworthiness risks (generated for example by aircraft limitations or by maintenance not executed) could be accepted by the crew/operator while, in the civil environment, a non-airworthy aircraft will never be intentionally operated.

Table 1. Comparison of primary characteristics of civil and military aviation

1.2 Qualification and certification in military aviation

An important difference between a civil and a military aircraft is represented by the purpose of the military aircraft, which is stipulated by the concept of operations (CONOPS) [2]. Under a defined CONOPS, the aircraft needs to satisfy specific operational, mission and performance requirements (military capabilities), which can be as important as airworthiness. The main objective for a civil airworthiness body is to ensure the safe flight of an aircraft while a military airworthiness body is responsible both for the safe and successful mission accomplishment. Thus, the management of airworthiness in military aviation can be similar, yet with distinct differences from how this is conducted in civil aviation.

The required military capabilities are related to a large number of operational environments (sometimes hostile or extremely hazardous) and mission profiles/roles (for example close air support, air-to-air refuelling, search and rescue, medical evacuation, offensive counter-air, suppression of enemy air defence, aerial delivery of paratroopers and loads, etc.). On the other hand, for civil aircraft the array of capabilities is limited and essentially the same for transport aircraft (which constitute the vast majority of fleets in commercial civil aviation). The military aircraft performance and operational requirements include some unique elements such as:

  • Specific missions, tasks and capabilities, with differing risk and acceptable levels of safety during peace and wartime

  • Various operational environments (different hazards, etc.)

  • Aircraft handling qualities

  • Weapons, ammunition stores and self-defence systems

Military aviation utilises the concept that the initial acceptable levels of safety may decrease during specific mission profiles [Reference Knight, Strunk and Sullivan3, Reference Isci4]. This triggers, as a side effect, a variation in the management of continuing airworthiness (i.e. maintenance activities), through, for example, the aircraft battle damage repair (ABDR) techniques or contingency maintenance (where in combat or under particular operational conditions, maintenance requirements can be relaxed or even waived).

Typically, military aircraft characteristics are designed, developed and demonstrated through qualification, which is the process used to verify and declare conformance with each operational requirement at all levels (usually specified in the procurement contract) [Reference Purton and Kourousis5Reference Jilian, Kangming and Lintong7]. In other words, qualification is the demonstration that the product is fit for purpose. In the qualification process the entire aircraft is assessed holistically, considering the design characteristics and operational use of all systems (structure, propulsion, flight controls, electrical system, hydraulics, armament, etc.). On the other hand, certification is the process employed to verify the airworthiness of a product. Qualification and certification shall be understood as mutually entwined processes overlapped in time. It is the aircraft specification that binds certification and qualification together. Those requirements that require demonstration of a minimum level of safety can be considered as certification, i.e. it shall be possible to perform the role of air-to-air refuelling tanker. Those requirements that require demonstration of the aircraft’s performance may be considered as qualification, i.e. in the air-to-air refuelling tanker role fuel is to be delivered at a rate of at least 100 litres per minute. It is often cost-effective to conduct the qualification and certification process in parallel [Reference Plankl8], ensuring also that way that the qualification characteristics will not affect the fitness for flight, namely airworthiness. The qualification activities shall result in the necessary evidence to allow judgement regarding the fulfilment of both types of requirements (military capabilities/performance and airworthiness). This, combined, process results in the production and acceptance of the Declaration of Design and Performance or a Certificate of Design, which could be considered equivalent to the Type Certificate [Reference Purton and Kourousis5]. Table 2 offers some examples which illustrate the relation between qualification and certification in military aircraft systems.

Table 2. Examples of qualification and certification processes of operational capabilities for military aircraft

It can be argued that qualification is still applicable to the civil environment; this is true for a limited number of cases (for example aircraft used for certain types of aerial work). However, this would be inconsiderable if compared to the military mission profiles or to the number of flight hours accrued by these services in relation to the total amount of the entire commercial air transport activity.

1.3 The need to regulate military airworthiness regulation in Europe

As discussed, there are some common aspects between the civil and military aviation; establishing a certain level of collaboration is therefore possible. Over the past years military aviation regulation globally has moved closer to the principles (and structure) of civil regulation [Reference Purton and Kourousis5, Reference Orío9–-Reference Hood, Sinha and Marzocca11]. This trend can be attributed to the actual (or perceived) benefits which may be gained from a civil-based approach, both in terms of safety performance, standardisation and harmonisation. For example, UK’s Defence Standard 00-970 ‘Design and Airworthiness Requirements for Service Aircraft’ Part 5 ‘Large Type Aeroplanes’ has adopted many of the EASA Certification Specifications (CS) 25 [12] requirements and Acceptable Means of Compliance [13]. Defence Standard 00-970 is a continuing evolving regulatory code whose origin can be traced back to the ‘Handbook of Strength Calculations’ introduced in 1916 [13]. A military – civil alignment is particularly important in multinational programmes, where different stakeholders, from various countries, have to work on the development, certification and production of aircraft/aeronautical products. Streamlining the process and saving time and resources can be achieved via standardisation/harmonisation of the regulatory requirements. Multinational programmes are characterised by being self-contained, i.e. ad-hoc working frameworks and agreements have to be set up between the different countries (governments) and the companies (industry). This requires a substantial investment in time, while any changes (eventually happening over the span of these multiyear projects) are creating an additional burden.

Examples from Europe include the Eurofighter programme [Reference Herrmann14Reference Heinrich17] (a large-scale industrial project), the Airbus A400M programme under the Organisation for Joint Armament Co-operation (Organisation Conjointe de Coopération en matière d’Armement, OCCAR) [18Reference Giry and Smith21] and the arrangement between the European Aviation Safety Agency (EASA) and the EDA on ‘Civil-Military Cooperation in Aviation Safety’ [22]. Also, in the United States (US), the Federal Aviation Administration (FAA) and the US Department of Defense have reached a collaboration agreement that allowed the creation of the FAA Military Certification Office [23, Reference Berlowitz24]. This was actioned through the FAA Order 8110.101 ‘Type Certification Procedures for Military Commercial Derivative Aircraft’ [25] and complemented by the Advisory Circular 20-169 ‘Guidance for Certification of Military and Special Mission Modifications and Equipment for Commercial Derivative Aircraft’ [26].

Nevertheless, it has to be recognised that the certification and, particularly, the qualification processes require access to information and data that could be classified, i.e. that cannot be disclosed. Therefore, special security clearances are typically requested in that case. This could impede or deter civil certification, making collaboration arrangements necessary for the completion of a civil-military project. In the case of the Airbus A400M certification by EASA, the type of aircraft (no weapons installed) did not raise the issue of security clearances and the few cases were be managed through ad-hoc actions but, if it had been a fighter aircraft, then the situation would be completely different. Nevertheless, certification also included consideration of additional military flight phases (aerial delivery, air-to-air refuelling) for safety assessments and structural load cases.

This paper reviews and discusses the harmonisation approach and progress made within Europe in the field of military airworthiness. It also attempts to map and critically comment on the main aspects of the military airworthiness frameworks established and currently operating in five European countries which have substantial activity in industrial projects, namely, France, Italy, Germany, Spain and the United Kingdom (UK).

2.0 Military airworthiness standardisation and harmonisation in Europe

In this section, the EDA military airworthiness harmonisation project is discussed, in conjunction with an overview of the management structures for military airworthiness in France, Italy, Germany, Spain and the UK.

2.1 The EDA military airworthiness harmonisation programme

From their experience running multinational programmes (TIGER helicopter, EF2000 fighter, etc.), European Union (EU) member states recognised that there were issues affecting the management of military airworthiness that had negative impact on the allocated budgets. Therefore, in 2008 the European National Armaments Steering Board tasked EDA to create a suitable forum for the Military Airworthiness Authorities (MAWA) [27] in order to address problems and/or avail of opportunities such as:

  • The lack of a common EU-wide approach to military airworthiness

  • The duplication of efforts and activities in the multinational programmes (especially in the field of military airworthiness)

  • The implementation of the EU Regulation 216/2008 (Ref. [28]), amended by the EU Regulation 2018/1139 [29], applicable to civil aviation, which required EU member states to ensure that military aircraft operation does not affect or decrease the safety of civil aviation and consequently the aircraft shall, at least, meet the same airworthiness characteristics

  • The enhancement of overall military aviation safety

  • The potential savings in terms of resources (time, funding, effort, etc.) from the application of common airworthiness management in multinational programmes

  • The benefits from a commonly shared military airworthiness approach and focal point enabling military and civil cooperation

  • The benefits for having a consistent and unique approach to airworthiness for industry

In order to accomplish these targets, it was decided to develop a common set of harmonised EMARs and related Acceptable Means of Compliance (AMC) and Guidance Material (GM) that could be used by the EU member states to create a common and standardised baseline. EDA also established that EMARs should be based on EU Regulation 216/2008 (Ref. [28]) taking, however, into account specific military aspects. This is described in the Basic Framework Document (BFD) [Reference Forum30], covering:

  • The role and functions of MAWA Forum

  • The commitments of the national military aviation authorities (NMAAs) and other stakeholders

  • The essential airworthiness requirements applicable to military aircraft and organisations covering all aspects of airworthiness

  • The creation of a European Military Joint Airworthiness Organisation (EMJAO).

It is of note that the BFD is not equivalent to the EASA Basic Regulation (EU Regulation 2018/1139 [29]). The EMARs and the MAWA-approved associated documents are requirements/guidelines and do not represent regulations. Therefore, the MAWA Forum has no authority on the airworthiness management of the EU member states. The decision on the implementation of the EMARs/MAWA Forum document remains a choice of the EU member state. Each state could opt for a full or a partial adoption or retain their own airworthiness management structure, demonstrating full or partial compliance with the EMARs/MAWA documents.

The EMAR documents follow the taxonomy of the EASA regulatory structure, as following [31]:

  • EMAR 21 ‘Certification of Military Aircraft and related Products, Parts and Appliances, and Design and Production Organisations’, covering the initial airworthiness of military aircraft

  • European Military Airworthiness Certification Criteria (EMACC), providing harmonised criteria for the certification of military aircraft

  • EMAR M ‘Continuing Airworthiness Requirements’, describing the requirements for ensuring the preservation of airworthiness, i.e. the requisites of organisations, materiel and personnel involved in the continuing airworthiness management

  • EMAR ‘Continuing Airworthiness Management Organisation (CAMO)’, defining the requisites of organisations and personnel involved in the continuing airworthiness management

  • EMAR 145 ‘Requirements for Maintenance Organisations’, establishing the requirements to be met by an organisation qualifying for the issuance or continuation of an approval for the maintenance of aircraft and components

  • EMAR 66 ‘Military Aircraft Maintenance Licensing’, stipulating the training requirements for aircraft maintenance personnel

  • EMAR 147 ‘Aircraft Maintenance Training Organisations’, covering the requirements to be met by organisations seeking approval to conduct aircraft maintenance training and examinations

In addition to the EMARs a set of explanatory documents explanatory documents was also developed:

  • EMAD 1 ‘Definitions and Acronyms Document’

  • EMAD R ‘Recognition’, describing the process employed for mutual recognition between two or more NMAAs, leading to the acceptance of the airworthiness activities carried out by the other NMAA

2.2 France

The French military airworthiness system has been originally controlled by the Directorate General of Armaments (DGA) (Direction Générale de l’Armement) [Reference l’armement32] and the services/other state operators Operators/Armed Forces (Air Force, Army, Navy, DGA Flight Testing, Gendarmerie, Civil Security and Customs). The DGA was mainly responsible for the initial airworthiness and procurement, while the continuing airworthiness management was under the responsibility of each service/state operator. The French Decree No 2006-1551 [33], amended by the French Decree No 2013-367 [34], expanded the airworthiness principles of the International Civil Aviation Organisation (ICAO) to military aircraft.

Following a study of the ‘Mission for Aviation In-Service Support Modernisation’ (Mission de modernisation du MCO aéronautique, MMAé), in 2008 [35] it was decided to establish an additional agency; the Directorate of State Aviation Safety (Direction de la Sécurité Aéronautique d’État, DSAE). This decision was reached due to the downsides of the previous system, for example dispersions and duplication of responsibilities between the DGA and the operators, and the need for coherence with the civil aviation structure. After a period of provisional operation, DSAE was formally instituted in 2013 with the French Decree No 2013-367 [34]. DSAE is the French NMAA and is responsible for:

  • Aircraft airworthiness

  • Air traffic, airspace and airport management

  • Aircrew training and aircraft operating rules

It is noted that DSAE is not a pure airworthiness authority since it is also responsibility over operational matters (air traffic management, aircrew, etc.). In particular, in the field of airworthiness, DSAE is responsible for the regulation and oversight of continuing airworthiness, while DGA remained competent for initial certification programme management and armaments procurement. Subsequently, two ministerial orders (in 2013) defined the duties of DSAE, DGA and of the aviation operating authorities (services/state operators) in relation to the use, airworthiness and registration of military aircraft and state-owned aircraft. The French regulation structure (FRA) is tailored to the EASA/EMAR systems, summarised as following:

  • Initial airworthiness [36]:

    • FRA 21J/EMAR 21J(FR) ‘Design’

    • FRA 21G/EMAR 21G(FR) ‘Production’

  • Continuing airworthiness [37]:

    • FRA M/EMAR(FR) M ‘Continuing Airworthiness Management’

    • FRA 145/EMAR(FR) 145 ‘Approved Maintenance Organisations’

    • FRA 147/EMAR(FR) 147 ‘Approed Maintenance Training Organisations’

    • FRA 66/EMAR(FR) 66 ‘Aircraft Maintenane Licencing’

Accident and incident investigation activities are under the responsibility of the Defence Accident Investigation Office (Bureau Enquêtes Accident Défense–air, BEAD-air) [38], which is an independent organisation under the Ministry of Defence. At the end of the investigation process, the BEAD-air produces safety recommendations for the agencies and for the services/state operators.

2.3 Germany

In accordance with the German Air Navigation Act (Luftverkehrsgesetz, LuftVG) [Reference Justiz39], the Federal Ministry of Defence (Bundeswehr) is the competent authority for the regulation of military aviation [40]. In the last decade, the Federal Ministry of Defence was involved in a re-organisation of the military airworthiness system and this process led to establishing (in 2014) the German Military Aviation Authority (MAA) (Luftfahrtamt der Bundeswehr) [41]. The rationale behind the established of a single NMAA in Germany was to concentrate all responsibilities in one body, namely for initial and continuing airworthiness. In the past, in accordance with the Bundeswehr Joint Service Regulation ZDv A-1525, the Bundeswehr Technical and Airworthiness Centre for Aircraft was the competent organisation for the initial airworthiness certification process [42], while the services were in charge for the continuing airworthiness issues. Certain activities, mainly related to industry certification, were under the responsibility of the Federal Office of Defence Technology & Procurement and Bundeswehr Quality Assurance Authority. In the previous structure there was a split of responsibilities, and this was the source of delays, hindering, in turn, international armaments’ projects.

The German MAA is independent from the Federal Office of Procurement and from the services, with the administrative control exercised by the chief of defence force. Also, it acts as a military authority directly subordinated to the Federal Ministry of Defence. The MAA is responsible for:

  • Future-oriented preparation and further development of regulations for military aviation

  • Certification of th German defence force aircraft and aeronautical systems, including supplementary equipment

  • Regulation and standardisation of military flight operations in Germany

  • Certification and recognition of agencies, authorities and institutions

  • Licensing of flying, technical and aeromedical personnel

  • Prevention of incidents and accidents involving military aircraft

The German MAA has fully transferred and translated the EMAR structure into the national law creating the DEMARs (German Military Airworthiness Requirements), with the following structure [40]:

  • DEMAR 21 ‘Certification of Military Aircraft and Related Products, Parts and Appliances, and Design and Production Organisations’

  • DEMAR M ‘Continuing Airworthiness Requirements’

  • DEMAR 145 ‘Requirements for Maintenance Organisations”

  • DEMAR 66 ‘Military Aircraft Maintenance Licensing’

  • DEMAR 147 ‘Aircraft Maintenance Training Organisations’

2.4 Italy

In accordance with the Italian law, the Presidential Decree No 270 [43], ratified by the Minister of Defence Decree 22 June 2011 [44], the Directorate of Air Armaments and Airworthiness (DAAA) (Direzione degli Armamenti Aeronautici e per l’Aeronavigabilità) is responsible for issuing technical regulation/directives for military aircraft airworthiness and related management, thus it operates as the NMAA for Italy. It is placed under the Secretary General of Defence/National Armament Director, which is part of the Italian Ministry of Defence responsible for armament policy, administrative co-ordination, armament procurement and relations with industries and international organisation.

The current Italian military airworthiness regulations is based on the following structure [45]:

  • Initial airworthiness:

    • AER(EP).P-2 ‘Military Aircraft Type Certification and Qualification; Suitability for Installation’

    • AER(EP).P-6 ‘Instructions for the Preparation of Technical Specifications/Certification Plans’

    • AER(EP).P-7 ‘Regulation for Recording and Maintaining the Military Aircraft Register’

    • AER(EP).P-10 ‘Design Organisation Military Approval’

    • AER(EP).P-11 ‘Mutual Recognition between Military Airworthiness Authorities for Delegation of Airworthiness Privileges’

    • AER(EP).P-16 ‘Procedure for Military Type Certification’

    • AER(EP).P-21 ‘Certification of Military Aircraft and related Products, Parts and Appliances, and Design and Production Organisations’

    • AER(EP).P-516 ‘Airworthiness Certification Criteria’

    • AER(EP).0-0-2 ‘DAAA Technical Publications System’

    • AER.0-0-8 ‘Technical Publications Amendment Process’

    • AER(EP).00-01-6 ‘Reporting and Management of Occurrences and Technical Warnings’

    • AER(EP).00-00-5 ‘Configuration Management and Airworthiness Directives’

  • Continuing airworthiness:

    • AER(EP).P-2005 ‘Aircraft Continuing Airworthiness Management’

    • AER(EP).P-145 ‘Requirements for Maintenance Organisations’

    • AER(EP).P-147 ‘Aircraft Maintenance Training Organisations Approval’

    • AER(EP).P-2147 ‘Approval of Organisations providing Training Services for Military Aircraft and/or its Components Maintenance Personnel’

    • AER(EP).P-66 ‘Military Aircraft Maintenance Licensing’

The implementation of the EMARs into the national system is an ongoing process that involves the incorporation of the entire document, for example AER(EP).P-21 and AER(EP).P-145, or the harmonisation and transposition of the EMAR requirement into the national structure. The DAAA framework allows running qualification and certification as two separate flows. However, if the two processes are conducted in parallel (i.e. synchronised), then it is possible to obtain a simultaneous recognition of the results; this procedure is called ‘homologation’. The accident and incident investigation activities are under the responsibility of every single service within the Italian defence force. However, in case of accidents, representatives of the DAAA are entitled to take part to the investigation board.

2.5 Spain

The Spanish Royal Decree 2218/2004 [46] approved the Regulation of Airworthiness of Defence (RAD) (Reglamento de Aeronavegabilidad de la Defensa). It also established that the Defence Airworthiness Authority (Autoridad de Aeronavegabilidad de la Defensa, AAD) [47] is the General Director of Armament and Material (Direccion General de Armamento y Material, DiGAM) [48], assisted by the Airworthiness Board (Consejo de Aeronavegabilidad), ratified by the Royal Decree 866/2015 [49]. The RAD also assigns the Airworthiness Board with the responsibility to support the work of DiGAM in relation to military and civil organisations and international airworthiness agencies, towards proposing and implementing international standards and practices that are of interest to the defence. It is noted that the synthesis of the Airworthiness Board includes representatives from DiGAM, the National Institute of Aerospace (Instituto Nacional de Tecnica Aeroespecial, INTA) [50] and the defence forces, as well as other technical bodies. Therefore, a variety of key stakeholders are members of the Airworthiness Board.

DiGAM and the Airworthiness Board are responsible for the initial and continuing airworthiness functions. In these duties, they are assisted by the INTA test centres which offer certification services for materials, components, systems related to aerospace equipment and weapons. DiGAM issues requirements and procedures related to continuing airworthiness, to be observed by each service/operator in the management of their fleets.

Apart from the Royal Decree 866/2015 [49], regulations are complemented by the following documents [47]:

  • DiGAM resolution 320/14251/12, establishing the Spanish Military Airworthiness Requirements Publications (Publicaciones Españolas de Requisitos de Aeronavegabilidad Militar, PERAM) as airworthiness requirements

  • DIGAM Resolution 320/14294/2013, defining airworthiness essential requirements

  • Airworthiness Board procedures

  • Internal procedures of the services/operators

In particular, the PERAMs are the translated versions, into Spanish, of the EMARs. The structure of the PERAMs is the following [47]:

  • PERAM 21 ‘Certification of Military Aircraft and Products, Components and equipment and Design and Production Organisations’ (Certificación de aeronaves militares y productos, componentes y equipos relacionados y de organizaciones de diseño y de producción)

  • PERAM M ‘Requirements for the continuation of airworthiness‘ (Requisitos para el mantenimiento de la aeronavigabilidad)

  • PERAM 145 ‘Requirements for Maintenance Organisations’ (Requisitos para las organizaciones de mantenimiento)

  • PERAM 147 ‘Requirements for Maintenance Training Organisations’ (Requisitos para las organizaciones de formación de mantenimiento)

  • PERAM 66 ‘Requirements for the Emission of Maintenance Licences’ (Requisitos para la emisión de licencias de mantenimiento)

Due to entry into service of new air systems and the participation to future programmes, the Spanish ministry of defence is redefining the current model. This “refresh” will include full implementation of the EMARs, refined competencies, and scope of the AAD, and revised functions of the Airworthiness Support Division [47].

2.6 United Kingdom

The UK MAA was established, via a Charter of the British Secretary of State for Defence, on the 1st of April 2010 [51] in response to the Haddon-Cave report in 2009 on the RAF Nimrod XV230 accident [52]. The Haddon-Cave report provided independent analysis of this accident, identifying systemic deficiencies related to the design and certification of a series of modifications and was instrumental in the revamp of the military airworthiness regulation system. The MAA incorporated the former Directorate of Aviation Regulation and Safety and became the single independent regulatory body within the British Ministry of Defence for all aviation activity. As the NMAA it covers all aspects of the aviation system, and it is responsible for:

  • Providing a regulatory framework

  • Performing the certification, approval and inspection processes for the acquisition, operation and airworthiness

  • Providing assurance that the appropriate level of safety is maintained

  • Performing the investigations of aircraft occurrences

With reference to the regulatory structure, the MAA has developed and issued (on behalf of the Secretary of State), the MAA Regulatory Publications (MRP) [53]; the system is based on three documentation levels, the Overarching Documents, Regulatory Articles and MAA Manuals. The UK regulatory system differs from the other national systems examined (France, Germany, Italy and Spain) in that it does not reflect a direct adoption of the EMARs/EASA structure. In particular, with regards to initial airworthiness, certification is governed by the Military Air System Certification Process (MACP) [54], which is based on EASA process after an adaptation to account for the specific military usage of the aircraft/aeronautical products. The application of MACP results into the issuance of a Military Type Certificate (MTC) to the Type Airworthiness Authorities (TAA). The issuance of a MTC demonstrates that the military air system Type Design meets the applicable airworthiness requirements after the satisfactory completion of the MACP. The TAA is within the UK Ministry of Defence the MTC holder.

In relation to continuing airworthiness, it is noted that according to GEN1000 Series Regulatory Articles RA1015 [55]: “Personnel appointed to principal Type Airworthiness management positions shall be responsible for the Type Airworthiness of an Air System throughout its life from development to disposal.” Moreover, GEN1000 Series Regulatory Articles RA 1016 requires that : “Delivery Duty Holders and Accountable Managers (Military Flying) shall ensure that the tasks associated with continuing airworthiness of the military registered Air Systems in their Area of Responsibility are managed by an approved Military Continuing Airworthiness Management Organisation (CAMO)”. The intent is to ensure the correct management of the Type Design (thus continued airworthiness) through-life and that military registered air systems are operated safely under an approved Military CAMO responsible for managing the continuing airworthiness tasks.

Moreover, it is highlighted that the initial and continuing airworthiness management is not performed only within the MAA, but also involves each Air System Delivery Team, under the delegation of authority issued by the MAA, which are based in the Defence Equipment and Support (DE&S) organisation. DE&S is responsible for the procurement of the various weapon systems. In particular, GEN1000 Series Regulatory Articles RA 1013 [56] stipulates that the DE&S Air Systems Operating Centre Directors “shall ensure that the Air Systems provided are airworthy and safe to operate through-life”. Thus, in the UK airworthiness system, the complete management of initial and continuing airworthiness is spread among the MAA and the DE&S.

With respect to the adoption of EMARs, the MAA had opted to implement the EMAR 21, M and 145, as these were considered to offer benefits in terms of safety improvements and reduced risks. However, based on an assessment performed in 2015 and reconfirmed in 2019, it has opted not to adopt EMAR 66 and 147, since similar benefits were not anticipated, nor foreseen.

2.7 Summary

The findings from the reviewed of the five countries, namely the four EU states and the UK, are summarised in Table 3. It is noted that most countries operate a single MAA, with the exception of France (DSAE-DGA). Also, Spain employs an Airworthiness Board for initial airworthiness matters, with a wide participation of stakeholders from the defence organisation and beyond. The adoption of EMARs has progressed substantially throughout the reviewed countries, however the regulatory structure presents differences. Moreover, the UK has elected not to adopt the maintenance licencing and training requirements (EMAR 66 and 147). On a different note, the distinction between technical and operational airworthiness, found in earlier versions of military airworthiness authorities, appears to have an effect on the transition to MAAs covering holistically airworthiness. For example, the German MAA and DSAE do cover aircrew licensing and training-licensing correspondingly, which is not the case for other countries.

Table 3. Summary of findings from the reviewed countries

3.0 Discussion

The following sections discuss in detail the current activity in Europe on military airworthiness harmonisation, as driven by EDA, and the current situation on military airworthiness management in the reviewed EU states and in the UK.

3.1 European military airworthiness harmonisation activity

The activity carried out by EDA under the MAWA initiative covers the certification processes, nevertheless qualification has remained outside of the scope of the EMARs. Also, safety regulations in relation to air traffic management services, airports and ground handling, aircrew licensing, etc. are not covered. The EDA framework for managing airworthiness may be satisfactory as starting point but its scope should be expanded if the objective would be to cover aviation safety more holistically, to encompass all aspects of the military aviation system. For example, qualification standards should be defined within aviation safety regulations, since for most military aircraft/aeronautical products the certification and qualification activities are rarely performed in isolation. To this end, it is of note that the US Military Standards (MIL-STD) and the North Atlantic Treaty Organisation (NATO) Standardisation Agreements (STANAG) are existing attempts to standardise military equipment and are referred to in aircraft technical specifications.

Currently the implementation of the EMARs by the EU member states, both in principle and each as a set of requirements/regulations, is a self-certified activity. Audits from other states are performed to verify their effective application only as part of mutual recognition initiatives.

Experience from international regulatory harmonisation efforts in civil aviation has also shown that a common set of requirements or even regulations does not automatically guarantee a consistent implementation. This is due to the discretion provided to the states, as, in the case of the EMARs, each NMAA has the ultimate responsibility for regulating military airworthiness in the way they consider best for the interest of their state. In such cases, the desired harmonisation objectives can only be met by centralising the management and decision-making process. This would require the establishment of a single European military airworthiness authority, which would inflict on the sovereignty of the EU member states. The military equivalent of EASA would have limited enforcement powers though and that would negate its purpose. An alternative would be the creation of an EU, or even an international, organisation similar to the predecessor of EASA, that of the Joint Aviation Authorities (JAA). This ‘military JAA’ should, however, be equipped with additional privileges and entitlements, such as the power to conduct audits and to issue safety recommendations. In that content, if the MAWA Forum would be the ‘military JAA’ it would need to establish an oversight system performing initial and regular inspections/audits to the EU member states that have declared compliance with the EMARs. This auditing system would be the equivalent to that employed in the NATO Recognition Process. This would ensure a common and standardised airworthiness system across the EU and any other countries that would willing to adopt that. A different option would be for EDA to employ a role similar to that of ICAO when it comes to auditing state aviation programmes. ICAO’s Universal Safety Oversight Audit Programme (USOAP) Continuous Monitoring Approach (CMA) is used to assess the effective implementation of the ICAO Standards and Recommended Practices (SARP) and other associated documents, by the Member States. This type of approach could be replicated in military aviation. As already seen with the NATO Recognition Process this is achievable, given that EU member states already have effective interaction with each other through other schemes. The EU Permanent Structured Cooperation (PeSCo) is one such example, providing ‘an effective binding legal framework to pioneer groups of willing Member States to move forward more rapidly on cooperation in the field of EU security, defence capability development and operations’ [Reference Orsini57]. The establishment of an overarching airworthiness organisation in the EU is already a target in the EDA MAWA Forum roadmap, as the creation of the EMJAO has been reported in the Basic Framework Document (BFD). However, so far, the exact structure, functions and responsibilities of EMJAO have yet to be released, thus the intensions of EDA are not known.

The civil aviation regulatory space is continuously evolving in the space of risk management, with EASA and FAA expanding the implementation of the Safety Management System (SMS) approach across most initial and continuing airworthiness activities. Since the EMAR framework traces the civil regulatory structure (namely that of EASA), the inclusion of SMS provisions in military regulations must be considered towards increasing confidence in the effectiveness of the overall military airworthiness management system [Reference Chatzi58]. With the release of EMAR CAMO [31], EDA has made the first step in that direction, adding the requirement for SMS in CAMOs. However, EDA and the NMAAs would first have to acknowledge, endorse and tailor the SMS principles, as described, for example, in the ICAO Annex 19 ‘Safety Management’ [59] and the ICAO Doc 9859 ‘Safety Management Manual’ [60].

3.2 Military airworthiness in the reviewed EU States and in the UK

The EU member states examined in this paper, and the UK cover the basis of the EMARs’ structure and their most important aspects (as outlined in the various documents), following in principle the MAWA Forum’s guidelines. However, all have yet to adopt a standard structure for their aviation/airworthiness authorities. For example, some states have established a single authority, while others two distinct authorities, one for the management of initial airworthiness and another for continuing airworthiness. In other cases, the authority may also be supported by external organisations. Moreover, there is not a common understanding of the various responsibilities for the stakeholders engaged in airworthiness management. For example, the Type Certificate holder, which in the civil aviation environment is usually the manufacturer (awarded through the Design Organisation approval), in military aviation may also be the operator or a different government organisation. This can be considered as a duplication of efforts as the Type Certificate might be managed by two (or more) stakeholders across different operators from different member states. Differing approaches followed by NMAAs may hinder mutual recognition, as a common baseline for certification (or continuing airworthiness approval) purposes would not be straightforward to establish.

4.0 Conclusion

This review has identified and discussed the following topics of importance in relation to the effective adoption and implementation of military airworthiness frameworks in Europe:

  • The civil and military convergence in airworthiness management in Europe has progressed significantly over the past 15 years.

  • The EMAR’s framework, developed and actively promoted by EDA, has enabled a gradual build-up of technical knowhow within the European states who elected to engage with the adoption of this civil-based airworthiness framework.

  • The establishment of a joint MAA is considered the next logical step in the overall process of harmonisation, in line with the objectives already set by EDA in relation to the creation of an EU-wide authority with greater powers.

  • Main players in the aerospace sector, such as France, Germany, Italy, Spain and the UK have adopted the EMAR approach, though through a variety of regulatory constructs.

  • The regulatory structure of the reviewed countries’ NMAAs has revealed a diverse practice, especially in how initial and continuing airworthiness management is performed (with some countries electing to have more than authority overseeing/been responsible for the corresponding activities).

  • Closer collaboration between the NMAAs can be achieved through the achieved standardisation at regulatory structure level.

Authors’ contributions

M. Pittini: Conceptualisation, methodology, investigation, data curation, formal analysis, validation, project administration, writing – original draft. K. I. Kourousis: Investigation, visualisation, validation, writing – review and editing.

Competing interests

The authors have no competing interests to declare.

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Figure 0

Table 1. Comparison of primary characteristics of civil and military aviation

Figure 1

Table 2. Examples of qualification and certification processes of operational capabilities for military aircraft

Figure 2

Table 3. Summary of findings from the reviewed countries