The issue is whether a major repair design that was approved on a specific component by an EU Member State prior to September 28, 2003 must be reevaluated by EASA before the component may be installed on an EU-registered aircraft.

A secondary issue is whether the identical repair may be performed on an article after the above date based on the same data approved by a Member State before the above date without submitting it to EASA for evaluation.

ARSA believes components that are repaired based on data approved by an EU Member State before September 28, 2003 should be eligible for installation on an EU-registered aircraft. “Safety is adequately assured by interpreting the grandfather provision to apply if the data was approved prior to 28 September 2003,” ARSA told EASA.

The Association will keep its members updated.

UPDATE: EASA replied on Sept. 11, 2006. Read the reply here (.pdf).

UPDATE 2: After a series of letters, ARSA has determined that EASA does not “grandfather” component level repairs that existed before September 28, 2003. Such repairs must be submitted for EASA repair design approval. Grandfathering only applies to repairs embodied in components that were actually installed on an EU-registered aircraft as of September 28, 2003.

In essence, EASA’s view is that grandfathering only applies to an entire aircraft. Therefore, component level repairs are only grandfathered on the components installed on an EU-registered aircraft before September 28, 2003; the repair design is not valid for accomplishment on similar components after that date.
Read the latest letter from EASA here (.pdf).