AD 85-21-51
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 767-200 Series | Airworthiness Directives; Boeing Model 767-200 Airplanes |
Unsafe Condition
Self-locking nuts in critical areas, such as elevator actuator rod end bolt joints, inboard trailing edge flap drive mechanisms, and outboard wing spoiler control systems, may fail to retain their self-locking feature, leading to bolt disconnection and potential loss of airplane control.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect self-locking nuts in elevator, inboard trailing edge flap, and outboard wing spoiler systems per Boeing Service Bulletin 767-27A0064. Replace insecure nuts before further flight with serviceable ones. Compliance must be within 35 landings or 10 days for elevator nuts, and within 50 landings or 20 days for flap and spoiler nuts.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 35 landings or 10 days after the effective date of this AD, whichever occurs first (for elevator nuts); within 50 landings or 20 days after the effective date of this AD, whichever occurs first (for flap and spoiler nuts).
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Boeing Model 767-200 airplanes, certificated in any category.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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