AD 85-23-51 R1
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Columbia Helicopters, Inc. | 234 | Airworthiness Directives; BOEING VERTOL COMPANY Model 234 Series Helicopters |
Unsafe Condition
Cracked main rotor head vertical hinge pins, P/N 114R2172-1, could cause possible hazards in flight.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Conduct a visual inspection using a light-assisted bore-scope for cracks on forward and aft main rotor head vertical hinge pins (P/N 114R2172-1) prior to further flight. Repeat daily inspections until replaced. Perform an eddy current inspection within 150 hours time in service from March 31, 1986, and a magnetic particle inspection within 500 hours time in service from the same date. Replace cracked pins before further flight.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Prior to further flight, within the next 150 hours time in service from March 31, 1986, and within the next 500 hours time in service from March 31, 1986.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Boeing Vertol Model 234 series helicopters 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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