AD 81-08-51
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Viking Air Limited | DHC-7-1 | Airworthiness Directives; DeHavilland Model DHC-7 Series Airplanes |
| aircraft | Viking Air Limited | DHC-7-100 | Airworthiness Directives; DeHavilland Model DHC-7 Series Airplanes |
| aircraft | Viking Air Limited | DHC-7-101 | Airworthiness Directives; DeHavilland Model DHC-7 Series Airplanes |
| aircraft | Viking Air Limited | DHC-7-102 | Airworthiness Directives; DeHavilland Model DHC-7 Series Airplanes |
| aircraft | Viking Air Limited | DHC-7-103 | Airworthiness Directives; DeHavilland Model DHC-7 Series Airplanes |
Unsafe Condition
Failure of the main landing gear to extend and possible malfunction of the flaps due to inadequate retention of barrel nuts DSC 100-8 under the bolts attaching actuator brackets and flap track brackets.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect bolts attaching main landing gear actuator brackets and flap track brackets by attempting rotation with specified tools. Replace barrel nuts DSC 100-8 with Esna barrel nuts P/N 2452-080 and washers as required, torque to specified values, and wirelock. Daily inspections are required for serial numbers 28-42 until replacements are done, with full replacement within 50 hours time-in-service after AD receipt.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
within the next ten hours time-in-service
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
DeHavilland DHC-7 series airplanes, serial numbers 3 through 42 inclusive
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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