ATOS is in use by 42 Certificate Management Teams. By the end of FY 07and ATOS Phase II, all Part 121 CMTs will be using ATOS, resulting in a single Part 121 air carrier oversight system.

ATOS is currently in use at:

  • American Airlines
  • United Airlines
  • Delta Airlines
  • US Airways
  • America West
  • Alaska Airlines
  • Continental Airlines
  • Northwest
  • Southwest
  • American Eagle
  • Skywest
  • Champion Airlines
  • ExpressJet
  • FEDEX
  • UPS
  • GoJet
  • Trans States
  • Ryan International
  • Air Midwest
  • Hawaiian Air
  • Horizon Airlines
  • AirTran
  • ASA
  • Comair
  • Champlain Enterprises DBA Commutair
  • Frontier Airlines
  • Frontier Flying Service
  • Everts Air
  • Cargo 360
  • Continental Micronesia
  • Aloha
  • Aviation Services
  • Hawaii Island Air, dba Island Air
  • Midwest Airlines
  • SkyWay
  • MESA
  • Freedom Airlines
  • Pinnacle Airlines
  • ASTAR Airlines
  • Tradewinds
  • PACE Airlines
  • Mountain Air Cargo