2) The above error in the acknowledgment was not corrected by ATC, meaning it was very likely that the crew of AEH993F did not know what would happen after point BL443 and were expecting to receive subsequent instructions, unsure if they would fly the transition. This error resulted in a breach of the provisions in Regulation (EU) No 923/2012, section SERA.8015 e) 3), since the controller did not ascertain that the clearance or instruction had been correctly acknowledged by the flight crew and did not take immediate action to correct any discrepancies revealed by the read-back.