IRImplementing rule
21L.A.91Changes to a part of a product covered by a supplemental type certificate
(a)A minor change to a part of a product covered by a supplemental type certificate shall be approved in accordance with Subpart D of this Annex.
(b)A major change to that part of a product covered by a supplemental type certificate shall be approved as a separate supplemental type certificate in accordance with this Subpart.
(c)By way of derogation from point (b), a major change to that part of a product covered by a supplemental type certificate submitted by the supplemental type-certificate holder may be approved as a change to the existing supplemental type certificate in accordance with points 21L.A.63 to 21L.A.69.
IR · 21L.A.91 — Regulation (EU) No 748/2012 · Regulation (EU) 2022/1358 · Initial Airworthiness Easy Access Rules · EAR revision 27 Nov 2025