Possible safety risks linked to “too much room” for interpretation of the EASA Part 21 product and parts certification regulation has prompted EASA to issue a notice of proposed amendment (NPA) to tighten the rule. It proposes to amend Part 21 to clarify that instructions for continued airworthiness (ICA) are part of the type certificate, and to develop the related acceptable means of compliance and guidance material. The NPA also merges the requirements related to record keeping, manuals, and ICA now in various subparts into a single requirement for each.

“Experience has shown that there is too much room for interpretation in the current rules and standards, leading to differences and possible safety risks,” EASA said. “It appears that different type certificate holders have different interpretations of what [constitutes] a complete set of ICA and to what level they are required to control the data that constitutes the ICA.”

The consequence is that maintenance organizations might not have all the necessary data to perform work in the correct way, which can lead to their using unapproved methods.

The NPA also discusses several drawbacks of the proposal, of which the main ones will be “the need for manufacturers to update the development processes of some ICA documents” and that this proposal will “potentially create dis-harmonization with U.S. standards.”

Comments on the proposal are due April 30. Based on the comments received, EASA will develop an opinion containing the proposed amendment and submit that opinion to the European Commission, which will use it to prepare an EU regulation. The final regulation is scheduled to be published late next year.