AD 74-22-06
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Viking Air Limited | DHC-6-1 | Airworthiness Directives; de Havilland Model DHC-6 Airplanes |
| aircraft | Viking Air Limited | DHC-6-100 | Airworthiness Directives; de Havilland Model DHC-6 Airplanes |
| aircraft | Viking Air Limited | DHC-6-200 | Airworthiness Directives; de Havilland Model DHC-6 Airplanes |
| aircraft | Viking Air Limited | DHC-6-300 | Airworthiness Directives; de Havilland Model DHC-6 Airplanes |
Unsafe Condition
Cracks in the horizontal stabilizer rear spars at the junctions of the spar webs with the top and bottom flanges between Stations 10.00 and 53.00.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect visually using a magnification glass of at least 10 power or an approved equivalent for spanwise cracks. If cracks are found, alter the spar per paragraph 2 of Service Bulletin 6/310 or approved equivalent before further flight. Equivalent inspections or alterations require approval from the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
within the next 50 hours in service or 1 week, whichever occurs first, after the effective date of this AD
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Affected Aircraft
de Havilland Model DHC-6 airplanes, Serial Numbers 1 to 393 inclusive excluding 107, 168, 182, 184, 209, 383, 385, 386, 390, and 391
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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