ARSA Offers EASA Objective Criteria for Assessing Part Criticality
On March 30, ARSA submitted comments to the EASA notice of proposed amendment (NPA 2017-19) regarding “installation of parts and appliances that are released without an EASA Form 1 or equivalent.” The association commended the agency’s effort but called out the NPA’s unnecessary complication of the rules and suggested a simpler, internationally-harmonized approach for assessing part criticality.
“This [NPA] aims to introduce more proportionate and efficient requirements in the airworthiness field, in particular to introduce commensurate manufacturing requirements for new spare parts and appliances,” EASA stated in its executive summary. “The requirement mandates that parts and appliances to be installed during maintenance need to be accompanied by [an EASA] Form 1 to attest manufacturing in accordance with Annex I (Part 21) to Regulation (EU) No 748/2012, which is considered, in certain cases, disproportionate.”
The NPA proposed giving the design approval holder responsibility to assign a criticality level for each aircraft part based on the safety consequences posed by the part’s potential failure. Should the DAH not make this assignment, the most-stringent level would become the “default.”
In its comments, ARSA noted support for the NPA’s intent and offered a simpler alternative to EASA’s proposal. The association noted that the agency’s proposed definitions for part criticality were different from those included in the approved design and that the DAH would be given full discretion for assessment. ARSA’s comments instead urged the adoption of three categories of parts – based on objective, design-based criteria – for use in determining required documentation for installation during maintenance or modification activities.
In the cover letter accompanying the comments, which were entered into EASA’s comment response tool, Managing Director and General Counsel Marshall S. Filler summarized the submission: “ARSA believes it has proposed a workable solution that (1) requires a Form 1 for all critical parts as defined in the design rules, (2) for non-critical parts, makes issuance of a Form 1 discretionary with a Part-21 subpart G or subpart F manufacturer, (3) for non-critical parts allows another document to be used in lieu of a Form 1 if it states that the article was produced under a Part-21 inspection system or quality system as applicable, and (4) allows maintenance providers to install parts that are not described above if they can establish a link to an approved design.”
To read the complete comments, including the regulatory language specifically suggested by ARSA, click here.
To see all of ARSA’s work related to parts documentation in the context of the U.S.-EU Maintenance Annex Guidance, visit arsa.org/mag.