AD 2021-26-07
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Airbus | Helicopters Model EC120B | Airworthiness Directives; Airbus Helicopters |
Unsafe Condition
recurring loss of tightening torque on several attachment bolts on the TR hub body, which could result in cracking and potential loss of the TR drive and consequent loss of yaw control of the helicopter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
perform repetitive inspections of the TR hub body for a crack and depending on the inspection results, removing the affected parts from service; inspect the TR spline flange for corrosion, impacts, fretting, wear, and a crack and depending on the inspection results, removing the TR splined flange from service; for helicopters with 9,000 or more total hours TIS or with unknown total hours TIS, removing from service any bolt, washer, and nut installed on the TR hub body, replacing them with airworthy parts, inspecting the TR splined flange, and depending on the inspection results, removing the TR splined flange from service; for helicopters with less than 9,000 total hours TIS, within 1,000 hours TIS or before accumulating 9,000 total hours TIS, whichever occurs first, and thereafter at intervals not to exceed 1,000 hours TIS, removing from service any bolt, washer, and nut installed on the TR hub body, replacing them with airworthy parts, inspecting the TR splined flange, and depending on the inspection results, removing the TR splined flange from service
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 15 hours TIS or 7 days, whichever occurs first, and thereafter at intervals not to exceed 1,000 hours TIS
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Affected Aircraft
Airbus Helicopters Model EC120B helicopters, all serial numbers
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 4, 2026
Rights: U.S. Government Public Domain
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