t) RTCA DO-260B to Part Number 622-9210-501. • Scheduling note: This item is a managed program; estimated downtime 15 - 20 working days. ASC 477A (Triple NZ) FMS 6.1 Upgrade • ASC 477A upgrades existing NZ 2000 Flight Management Systems (FMS), via installation of version 6.1 software, to an NZ 2010 sys