AD 83-21-03
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Viking Air Limited | DHC-7-1 | Airworthiness Directives; DeHavilland Model DHC-7 Airplanes |
| aircraft | Viking Air Limited | DHC-7-100 | Airworthiness Directives; DeHavilland Model DHC-7 Airplanes |
| aircraft | Viking Air Limited | DHC-7-101 | Airworthiness Directives; DeHavilland Model DHC-7 Airplanes |
| aircraft | Viking Air Limited | DHC-7-102 | Airworthiness Directives; DeHavilland Model DHC-7 Airplanes |
| aircraft | Viking Air Limited | DHC-7-103 | Airworthiness Directives; DeHavilland Model DHC-7 Airplanes |
Unsafe Condition
Failure of the pilot valve of the ground spoiler valve No. 2 could result in uncommanded operation of the ground spoilers during flight, leading to potential loss of control.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Perform an operational check of the ground spoiler system within 25 flight hours from the AD effective date, and repeat the functional checks every 800 flight hours. Use DeHavilland Alert Service Bulletin A7-27-56 for instructions. Alternate means of compliance may be approved.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 25 flight hours from the effective date of this AD
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Affected Aircraft
DeHavilland model DHC-7 airplanes equipped with ground spoiler valves per modification No. 7/1732, including DHC-7-1, DHC-7-100, DHC-7-101, DHC-7-102, DHC-7-103 models.
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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