AD 2021-13-21
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Aviat | Various | Airworthiness Directives; Leonardo S.p.a. Helicopters |
Unsafe Condition
Corrosion, cracking, and damage to the adhesive (e.g., disbonding) of any stainless steel external ring bonded to the main rotor swashplate boot, which could result in release of a ring from the main rotor swashplate boot, resulting in damage to, and reduced control of, the helicopter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Accomplish the actions specified in EASA AD 2020-0271, described previously, as incorporated by reference, except for any differences identified as exceptions in the regulatory text of this AD. This includes repetitive detailed inspections (DET) of the affected external rings for corrosion (including superficial oxidation), and cracks, and, depending on findings, polishing corrosion, and replacing an affected external ring with a serviceable part. EASA AD 2020-0271 also requires repetitive inspections for damage of the adhesive (e.g., disbonding) between the bonding areas of the affected external rings and the main rotor swashplate boot and re-applying the adhesive if necessary. For certain helicopters, EASA AD 2020-0271 requires a one-time restoring of the adhesive between the bonding areas of the affected external rings and the main rotor swashplate boot. For all helicopters, EASA AD 2020-0271 allows, under certain conditions, (re)installation of an affected part on a helicopter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Before further flight
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Leonardo S.p.a. Model AB139, AW139, and AW189 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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