AD 2025-15-02

final rule
Data completeness: 80%

Airworthiness Directives; Siam Hiller Holdings, Inc.

AD Number
2025-15-02
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. FAA-2024-2555
FR Citation
90 FR 40529

Unsafe Condition

Cracks found in the main rotor (M/R) transmission drive shaft (drive shaft) could result in separation of the M/R drive shaft and M/R blades 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

Inspect certain M/R drive shafts for cracks. Prohibit installing certain M/R drive shafts unless the inspection is completed. Prohibit using certain paint strippers.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Within 4 years of the effective date of this AD or at the next M/R transmission assembly overhaul inspection after the effective date, whichever comes first.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Siam Hiller Holdings, Inc., Model UH-12E (Army OH-23G and H-23F) and UH-12E-L helicopters.

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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View Official Source ↗