AD/EMB-120/40 - Elevator Torque Tubes

This Airworthiness Directive requires all Embraer EMB-120 operators to inspect and, if necessary, repair or replace elevator torque tubes in accordance with Embraer Service Bulletin No. 120-55-0015 (or a later CTA‑approved revision) (Requirement). The work must be completed within 4,000 flight hours or 730 days from 16 February 2006; CASA issued the AD after corrosion was found on torque‑tube inner surfaces, so operators bear inspection and repair costs and must schedule maintenance to mitigate controllability risk (Compliance; Background).