AD 2011-12-16
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Schweizer | Various | Airworthiness Directives; Schweizer Aircraft Corporation (Schweizer) Model 269A, A-1, B, C, C-1, and TH-55 Series Helicopters |
Unsafe Condition
A locknut working loose from a bolt attaching the tailboom support strut at the aft cluster fitting, due to improper threads on the locknut, could cause the strut and driveshaft to separate from the helicopter, leading to loss of control.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Within 10 hours time-in-service (TIS), modify both expandable bolts by drilling a hole through each bolt to allow the addition of a cotter pin. Thereafter, do not install an expandable bolt unless it has been modified in accordance with this AD.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 10 hours time-in-service (TIS)
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Affected Aircraft
Schweizer Aircraft Corporation Model 269A, A-1, B, C, C-1, and TH-55 Series helicopters.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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