Rotor Drive() – Tail Rotor Drive Flange – Modification
Superseded. Comply with 2020-0212, which replaces this document.
- Published
- Effective
- Deadline
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Operators of affected Airbus Helicopters SA 365 N1, AS 365 N2, AS 365 N3, EC 155 B, and EC 155 B1 models must modify the main gearbox tail rotor drive flange within 600 flight hours or 12 months from 25 March 2019, whichever occurs first. The modification must follow the instructions in the applicable Airbus Helicopters Alert Service Bulletins AS365-63.00.19 Revision 1 or EC155-63A013 Revision 1. Helicopters already modified according to earlier versions of these service bulletins are considered compliant.
Summary
EASA Airworthiness Directive 2019-0046 is an airworthiness directive issued by the European Union Aviation Safety Agency affecting Airbus Helicopters SA 365, AS 365, and EC 155 models. It addresses a safety issue related to the tail rotor drive flange of the main gearbox on these helicopters, specifically concerning the Shur-Lok nut that retains the tail rotor drive flange. The directive mandates a modification to prevent potential loss of tail rotor drive control.
What changed
EASA Airworthiness Directive 2019-0046 introduces a mandatory modification of the main gearbox tail rotor drive flange to install a rear output stop with five spigots on the tail rotor shaft flexible coupling. This modification replaces previous inspection requirements from earlier directives and aims to prevent the Shur-Lok nut from loosening and disengaging. The directive also accepts prior modifications done according to earlier Airbus Helicopters Alert Service Bulletins as compliance.
Why it matters
This directive is critical for aviation professionals because failure to comply could result in loss of tail rotor drive control, increased vibrations, and reduced helicopter controllability, posing significant safety risks. Operators and maintenance organizations must ensure compliance to maintain airworthiness and avoid operational restrictions. The directive also streamlines compliance by superseding previous inspection mandates, reducing repetitive maintenance actions.
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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