The company said in an SEC filing that it became aware of the cybersecurity incident on September 19. The disclosure does not mention Collins Aerospace, the subsidiary that offers the impacted airport check-in and boarding solutions. RTX confirmed that customers have resorted to backup and manual processes, which has led to flights being delayed and cancelled. The company explained that ransomware was found on "systems that support its Multi-User System Environment (MUSE) passenger processing software," adding, "This software enables multiple airlines to share check-in and gate resources at airports, including baggage handling.