AD 79-11-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | FH1100 Manufacturing Corporation | 1100 | Airworthiness Directives; Fairchild (Hiller) Model 1100 and FH-1100 Helicopters |
| aircraft | FH1100 Manufacturing Corporation | FH-1100 | Airworthiness Directives; Fairchild (Hiller) Model 1100 and FH-1100 Helicopters |
Unsafe Condition
Cracking of the transmission lower housing gimbal ring support.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect and repair P/N 24-23030-7 transmission lower housings with 500+ hours since new/overhauled within 50 hours after AD effective date or last 500 hours, repeating every 500 hours. Ream gimbal ring mounting holes to next size for housings with 1200+ hours within 100 hours after AD effective date or last 1100 hours, repeating every 1200 hours. Retire housings if hole diameter exceeds 0.8755 inch or total time reaches 3600 hours. Install P/N 24-23030-11 to exempt from AD.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
within 50 hours after the effective date of this AD, unless already accomplished within the last 500 hours... within 100 hours after the effective date of this AD and at each 1200-hour interval thereafter... upon installation of P/N 24-23030-11
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Fairchild (Hiller) Model 1100 and FH-1100 helicopters with P/N 24-23030-7 transmission lower housings installed in P/N 24-23000-11, -31, and -41 transmission assemblies
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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