Tail Rotor – Double Bearing – Inspection / Replacement
Superseded. Comply with 2021-0170, which replaces this document.
- Published
- Effective
- Deadline
- Replaces
- 2019-0267R1
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Operators of Airbus Helicopters SA 365, AS 365, and EC 155 must perform repetitive inspections of the tail rotor gearbox chip detector at specified intervals based on flight hours accumulated by the double bearing. Double bearing washing and replacement must be conducted within defined flight hour limits, with replacement required before 610 flight hours or within 110 flight hours after 28 October 2019, whichever is later. All inspections and corrective actions must follow the applicable Airbus Helicopters service bulletins and maintenance manual instructions.
Summary
EASA Airworthiness Directive 2020-0078 is an airworthiness directive issued by the European Union Aviation Safety Agency affecting Airbus Helicopters models SA 365, AS 365, and EC 155. It addresses the inspection and replacement requirements for double bearings installed on the tail rotor gearbox, specifically part numbers 704A33-651-245 and 704A33-651-246. The directive aims to ensure continued safe operation by mandating repetitive inspections and timely replacement of these parts to prevent loss of yaw control.
What changed
EASA Airworthiness Directive 2020-0078 supersedes the previous directive 2019-0267R1 and introduces reduced inspection intervals for the tail rotor gearbox chip detector on affected helicopters. It retains the previous inspection and replacement requirements but shortens the time between inspections for certain groups of helicopters. The directive also updates the service bulletin revisions and clarifies compliance procedures for close monitoring and part replacement.
Why it matters
This directive is critical for aviation professionals as it addresses a safety risk related to the degradation of tail rotor gearbox double bearings, which could lead to loss of yaw control. Operators and maintenance organizations must comply with the updated inspection intervals and replacement schedules to maintain airworthiness and prevent potential accidents. Compliance ensures continued safe operation and adherence to European aviation safety regulations.
More for Airbus Helicopters SA
All 58- EASA AD 2026-0195Tail Rotor Drive – Tail Gear Box Control Rod Bearings – Replacement / Life LimitationOct 13, 2026
- EASA PAD 26-105Tail Rotor Drive – Tail Gear Box Control Rod Bearings – Replacement / Life LimitationSep 11, 2026
- EASA AD 2026-0118Rotors Flight Control – Tail Rotor Actuator – InspectionJun 22, 2026
- EASA AD 2026-0029Tail Rotor Drive — Tail Gear Box Input Flange — Functional ChecksFeb 12, 2026
- EASA PAD 26-017Powerplant — Engine Firewalls — Modification
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