Tail Rotor — Tail Gearbox Angular Clearance — Inspection
- Published
- Effective
- Deadline
- Replaces
- 2021-0184R1
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Operators of AS 332 L2 and EC 225 LP helicopters must inspect the angular clearance of affected tail gearboxes within 110 flight hours from 19 August 2021 and at specified intervals thereafter. If clearance exceeds 0.69 mm, the tail gearbox must be replaced before the next flight. Repetitive inspections are required with specific intervals based on clearance measurements, and installation of affected parts is only allowed if they are serviceable and inspected accordingly.
Summary
EASA Airworthiness Directive 2021-0184R2 is an updated safety directive addressing the inspection of tail gearbox angular clearance on Airbus Helicopters AS 332 L2 and EC 225 LP models. It mandates repetitive inspections of specific tail gearbox parts to detect angular clearance issues that could lead to structural failure of the tail gearbox drive. The directive applies to tail gearboxes with part numbers 332A36.3001.00, 332A36.3002.00, and 332A36.5001.01.
What changed
This revision corrects the allowable angular clearance range to align with the Airbus Helicopters Alert Service Bulletin, relaxing the previously stricter limits. It maintains the requirement for repetitive inspections and replacement of affected parts if clearance exceeds the specified threshold. The directive remains an interim measure pending further investigation.
Why it matters
This directive is critical for operators and maintenance teams to prevent potential loss of control due to tail gearbox failure caused by loss of tightening torque and spline degradation. Compliance ensures continued airworthiness and safety of affected helicopters. It also clarifies inspection intervals and acceptance criteria, aiding in consistent maintenance practices.
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