EASA AD 2021-0282R1
[Correction] Tail Rotor — Tail Rotor Head Pitch Change Unit Bearing Spacer — Marking / Check
Summary
EASA Airworthiness Directive 2021-0282R1 is a correction to the original AD addressing the tail rotor head pitch change unit bearing spacer on Airbus Helicopters AS 350 and AS 355 models. It mandates inspections, marking, and checks of specific tail rotor head spider pitch change units to prevent loss of pitch change control. The directive applies to all serial numbers of the affected helicopter models and specifies part numbers 350A33-2030-00, 350A33-2167-00, and 350A33-2167-01.
What Changed
This revision removes repetitive check requirements that have been incorporated into the updated Aircraft Maintenance Manual Airworthiness Limitations Section. It also corrects typographical errors in referenced AD numbers and modifies paragraph titles by removing the word 'repetitive'. The AD now aligns with recent maintenance manual updates and supersedes the original AD 2021-0282.
Why It Matters
For aviation professionals, this AD ensures continued safe operation of affected helicopters by addressing a critical potential failure in the tail rotor pitch change mechanism. Operators and maintenance teams must comply to avoid loss of helicopter control due to excessive wear or play in the tail rotor assembly. The update clarifies compliance responsibilities and integrates maintenance procedures into the approved maintenance manual, streamlining ongoing airworthiness management.
What To Do
Operators of Airbus Helicopters AS 350 and AS 355 models with affected parts must perform a one-time check of the spider pitch change nut within 50 flight hours after 31 December 2021. If the nut is present and in good condition, apply a black paint index marking before the next flight and perform a visual check within 10 flight hours after marking installation. Any discrepancies require immediate inspection and possible replacement of the tail rotor rotating plate before further flight. Installation of affected parts is allowed only after compliance with these checks and markings.