EASA AD 2025-0038
Rotors Flight Control — Pilot Interconnecting Cyclic Pitch Torque Tube Assembly — Inspection
Summary
EASA Airworthiness Directive 2025-0038 is an airworthiness directive addressing the inspection of the pilot interconnecting cyclic pitch torque tube assembly on MECAER AVIATION GROUP S.p.A. NH-500D and AMD500N helicopters. The directive applies specifically to NH-500D helicopters with serial number BH13 and AMD500N helicopters with serial number 301. It mandates inspections of torque tube assemblies with part numbers 369A7109-601, 369H7133-501, or 369N2618-601 to ensure continued airworthiness.
What Changed
This new airworthiness directive introduces mandatory repetitive inspections and functional checks of the pilot interconnecting cyclic pitch torque tube assembly and its roller bearings. It requires operators to inspect for cracks, corrosion, looseness, binding, or ratcheting and to perform corrective actions if any defects are found. The directive also references MECAER AVIATION GROUP Service Bulletin BN-500-149 / BN-500N-038 as the source of inspection and corrective procedures.
Why It Matters
This directive is critical for aviation professionals because failure of the torque tube assembly can impair longitudinal control of the helicopter, potentially leading to loss of control and emergency landings. Operators and maintenance organizations must comply to prevent unsafe conditions caused by seized or damaged roller bearings within the torque tube assembly. Ensuring compliance helps maintain flight safety and regulatory adherence for affected NH-500D and AMD500N helicopters.
What To Do
Operators of affected NH-500D and AMD500N helicopters must perform a full-range freedom-of-movement functional check and detailed inspection of the torque tube assembly within 100 flight hours after 28 February 2025, and then at intervals not exceeding 100 flight hours. If any cracks, corrosion, looseness, binding, or ratcheting are detected, corrective actions must be completed before the next flight following the instructions in the referenced MECAER AVIATION GROUP Service Bulletin. No terminating action is provided, so inspections must continue indefinitely.