AD 85-18-05 R2
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sikorsky Aircraft Corporation | S-61A | Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61L, S-61N, S-61NM, and S-61R, S-61A, S-61V Series Helicopters |
| aircraft | Sikorsky Aircraft Corporation | S-61L | Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61L, S-61N, S-61NM, and S-61R, S-61A, S-61V Series Helicopters |
| aircraft | Sikorsky Aircraft Corporation | S-61N | Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61L, S-61N, S-61NM, and S-61R, S-61A, S-61V Series Helicopters |
| aircraft | Sikorsky Aircraft Corporation | S-61NM | Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61L, S-61N, S-61NM, and S-61R, S-61A, S-61V Series Helicopters |
| aircraft | Sikorsky Aircraft Corporation | S-61R | Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61L, S-61N, S-61NM, and S-61R, S-61A, S-61V Series Helicopters |
| aircraft | Sikorsky Aircraft Corporation | S-61V | Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61L, S-61N, S-61NM, and S-61R, S-61A, S-61V Series Helicopters |
Unsafe Condition
Main rotor spar crack and possible loss of the helicopter during operation with unapproved main rotor blades in Part 133 external load operations.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace unapproved main rotor blades with approved blades within 25 hours time in service. Inspect VBIM indicators within 1 1/2 hours time in service and conduct subsequent inspections prior to first flight daily and every 1 1/2 hours. For CBIM-equipped helicopters, test systems every 8 hours time in service and check electrical circuits hourly during flight. Address indications per SB 61B15-6.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next 25 hours time in service after the effective date of this AD, unless already accomplished.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Sikorsky Model S-61L, S-61N, S-61NM, S-61R, S-61A (S/N 61083, 61087, 61094, 61161), and S-61V (S/N 61271) helicopters engaged in more than six external cargo lifts per flight hour under Part 133, Class B operations.
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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