EASA AD 2025-0027
Main Rotor — Swashplate Inner and Outer Ring Bolts — Inspection / Replacement
Summary
EASA Airworthiness Directive 2025-0027 is an airworthiness directive addressing the inspection and replacement of main rotor swashplate inner and outer ring bolts on MBB-BK117 D-3 and D-3m helicopters. It applies to swashplates with part number D623M2050102 up to serial number 0503, excluding certain serial numbers and those already inspected and corrected. The directive mandates inspection and replacement of bolts to ensure structural integrity of the swashplate.
What Changed
This new airworthiness directive introduces a one-time inspection requirement for the swashplate bolts and associated parts due to reports of over torqued bolts found both in service and on production helicopters. It requires removal and inspection of the 24 bolts, replacement of any damaged control or bearing rings, and installation of new bolts. Additionally, it prohibits installation of affected swashplate parts from the effective date onward.
Why It Matters
This directive is critical for aviation professionals because over torqued bolts can compromise the structural integrity of the swashplate, potentially leading to unsafe flight conditions. Operators and maintenance organizations must comply to prevent damage and ensure continued airworthiness. Compliance teams need to track affected helicopters and ensure timely inspections and part replacements to avoid grounding or regulatory violations.
What To Do
Operators of MBB-BK117 D-3 and D-3m helicopters with affected swashplates must perform the inspection within 50 flight hours or 1 month from 19 February 2025, whichever comes first. If discrepancies are found, replace the control or bearing ring and install new bolts before the next flight. Even if no discrepancies are found, replace the bolts with new ones before the next flight. No affected swashplate parts may be installed on any helicopter after the effective date.