Every time a new type of aircraft or aeronautical product is developed (civil or military), its compliance with established minimum safety standards must be demonstrated from the outset, i.e. during the design phase. For standard applications, such as commercially used passenger and transport aircraft or helicopters, tailored sets of technical airworthiness requirements are summarised in ‘airworthiness codes’, also known as certification specifications, and used as the basis for the verification tests to be performed as part of the airworthiness certification process.

With the approval by Defence Ministers in 2008 of the ‘roadmap for the EU-wide forum for Military Airworthiness Authorities (MAWA)’, representatives and subject matter experts of national military airworthiness authorities were tasked to work on ’common certification/ design codes’ for military aircraft and aeronautical products. 

However, as innovation constantly delivers new materials, technologies and design features, predefined airworthiness codes need to be adapted (for each product certification) as they don’t cover all the necessary elements to assess a new product’s airworthiness. In such cases, special requirements must be agreed between the manufacturers and the airworthiness authorities. 

In contrast to the civil aviation industry, where new technologies tend to be introduced rather gradually and smoothly, the value of a new military air asset depends first and foremost on the disruptiveness of its technology and its – often unusual — design. As a result, a simple adaptation of traditional airworthiness codes, in many cases, does not suffice and tailor-made military-specific airworthiness certification programmes must be developed instead.

Against this backdrop, a dedicated Task Force was established in 2009 under the direction of the EDA Military Airworthiness Authorities (MAWA) Forum to develop a harmonised apprach to generic airworthiness certification criteria that could be used to assess and certify the design-airworthiness for all EU military aircraft programmes.

Building on the US handbook

Since 2009, a European Military Airworthiness Certification Criteria (EMACC) handbook has been gradually developed, building on the work of the US Department of Defense which issued the Mil-HdBk 516, a document containing airworthiness certification criteria for use in all new US military fixed wing aircraft programmes. The EMACC Handbook contains qualitative A guide to ever safer military aircraft criteria that should allow Airworthiness Authorities and manufacturers to define appropriate requirements to be met in order to reduce risks in system safety for each specific case. 

The MAWA Forum Task Force aligned and combined the MIL-HdBk 516 criteria with the specific airworthiness requirements of European and US civil airworthiness codes and equivalent defence standards, including UK Defence Standards (DEF-STAN) and NATO Standardization Agreements (STANAGs). Thanks to the efforts made by the national experts of the MAWA Task Force and the technical support provided by EDA, the first edition of the fully harmonised EMACC document was issued at the end of 2012. 

Today, the 3rd edition of the EMACC handbook, fully aligned with the US MIL-HdBk 516 Issue C, can be downloaded from the EDA website here.

Several national military airworthiness authorities already require contractors to use it on a mandatory basis. 

 

Way ahead

Building on user feedback and lessons learned, the EMACC Handbook will be further developed and improved under the responsibility of the Design and Production Advisory Group (DPAG) of the EDA – Military Airworthiness Authorities (MAWA) Forum. The next edition, scheduled to be issued by 2020, is set to include more guidance on the tailoring process as well as additional references and criteria to cover the latest Remotely Piloted Aircraft Systems (RPAS) certification standards, Air-to-Air Refuelling (AAR) operations, ship-borne operations and cyber threats.

 

You were among the first manufacturers to use the EMACC for establishing a Certification Basis. What was your overall experience? 

The EMACC has been used by the company to establish the Certification Basis for a new helicopter, as a complement to the EASA CS-29 which was the main pillar of the airworthiness requirements. As such, the definition of the applicable standard for each criterion was straightforward, since EMACC was used to define standards only for those criteria not covered already by CS-29. The selection has been easily accomplished thanks to previous Company and Authority experience in similar applications, nevertheless, some degree of guidance in the choice of standards would have been beneficial to the process. The resulting Type Certification Basis (TCB) has been positively evaluated by the Authority and has been agreed with no major discussions.


For which activities or applications would you say the EMACC is the most relevant tool?

The EMACC could of course be applied to define the certification basis for new types or modifications of military aircraft. In addition, the EMACC could be used to verify the completeness of an already existing TCB. For dual use (civil/military) applications, it is essential to define the additional airworthiness criteria to complement a civil-based TCB when used for military applications. 


How could the EMACC be further improved in the future?

Regarding our specific product, the EMACC could be improved by introducing new topics such as more detailed safety criteria for helo-ship operations. In addition, selection criteria among the different standards could be added. As it is, the EMACC is for the sole use of experienced airworthiness specialists: additional guideline material to select the appropriate standards for the different applications could be of use for small or new NMAAs and could support the uniformity of criteria across the Member States. For rotary wing applications, only the CS-29 has been provided with standards for some criteria: this may not be the most adequate standard for cases such as flight or crash loads definition.

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