AD 2021-17-15

final rule
Data completeness: 80%

Airworthiness Directives; Leonardo S.p.a. Helicopters

AD Number
2021-17-15
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. FAA-2021-0463
FR Citation
86 FR 50219

Applicability

TypeManufacturerModelDetails
aircraft Leonardo S.p.a. Airworthiness Directives; Leonardo S.p.a. Helicopters

Unsafe Condition

An in-flight loss of a main rotor blade (MRB) tip cap due to incorrect bonding procedures on certain MRBs.

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Required Actions

Inspect the MRB tip cap for disbonding using a tap test. If disbonding is found, tap inspect the disbonded area within 10 hours TIS and thereafter at intervals not to exceed 10 hours TIS. If disbonding exceeds permitted limits, replace the part. Tap inspect the MRB tip cap at intervals not to exceed 50 hours TIS if no disbonding is found. Accumulation of 1,200 total hours TIS on the affected part without findings of any disbonded area or with findings of any disbonded area that is within the permitted limits in Annex A of ASB 139-520 constitutes terminating action for the repetitive inspections.

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Compliance Time

Within 50 hours TIS, and thereafter at intervals not to exceed 50 hours TIS.

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Affected Aircraft

Leonardo S.p.a. Model AB139 and AW139 helicopters with main rotor blades (MRBs) part number (P/N) 3G6210A00131 with any serial number listed in Table 1 of Leonardo Helicopters Alert Service Bulletin No. 139-520, dated April 26, 2018, installed.

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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