AD/CESSNA 550/13 - Bleed Air Check Valve - CANCELLED

What this does: This document cancels an old aircraft safety rule (an Airworthiness Directive) that required owners of Cessna 550 business jets to replace faulty bleed air check valves (parts that prevent air pressure from flowing backwards in the engine system).

Who it affects: Owners and operators of Cessna 550 (Citation II) series aircraft. In practice, this affects almost no one today, as the original rule required compliance by 1986—meaning all affected planes were modified decades ago.

Why it matters: It formally removes a 23-year-old maintenance requirement that has become redundant. This is regulatory housekeeping—cleaning up obsolete rules so operators don't have to track requirements that no longer serve any safety purpose.