EASA AD 2026-0033 — Engine — High-Pressure Turbine Inner Stationary Seal — Inspection
Summary
EASA Airworthiness Directive 2026-0033 is issued for CFM International CFM56-5B, CFM56-5C, and CFM56-7B engines installed on aircraft including Airbus A318, A319, A320, A321, A340 and Boeing 737-600 through 737-900ER series. The directive mandates inspections of the high-pressure turbine inner stationary seal and the rotating air high-pressure turbine front seal to detect cracks or honeycomb separation. It addresses potential risks of seal failure that could lead to uncontained engine damage and possible harm to the aircraft.
What Changed
This new airworthiness directive introduces mandatory borescope inspections and engine shop visit inspections for affected high-pressure turbine seals on specified CFM56 engine models. It requires corrective actions if damage or honeycomb separation is found and prohibits installation of affected parts after inspections. The directive also establishes compliance intervals and defines terminating actions for repetitive inspections.
Why It Matters
This directive is critical for aviation professionals to prevent potential engine failures caused by damaged turbine seals, which could result in uncontained engine events and aircraft damage. Operators and maintenance organizations must ensure timely inspections and repairs to maintain airworthiness and regulatory compliance. It helps mitigate safety risks associated with specific seal part numbers and serial numbers identified as defective.
What To Do
Operators must perform borescope inspections of the rotating air high-pressure turbine front seal within specified flight cycle intervals starting from 6 March 2026, and conduct inspections of the high-pressure turbine inner stationary seal during the next engine shop visit. If damage or honeycomb separation is detected, corrective actions must be taken before further flight. Installation of affected parts is prohibited after inspections or from the effective date for certain engine groups. Compliance with the service bulletins referenced in the directive is required.