AD 73-20-05

final rule
Data completeness: 70%

Airworthiness Directives; de Havilland Model DHC-6 Twin Otter Floatplanes all Series

AD Number
73-20-05
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Viking Air Limited DHC-6-1 Airworthiness Directives; de Havilland Model DHC-6 Twin Otter Floatplanes all Series
aircraft Viking Air Limited DHC-6-100 Airworthiness Directives; de Havilland Model DHC-6 Twin Otter Floatplanes all Series
aircraft Viking Air Limited DHC-6-200 Airworthiness Directives; de Havilland Model DHC-6 Twin Otter Floatplanes all Series
aircraft Viking Air Limited DHC-6-300 Airworthiness Directives; de Havilland Model DHC-6 Twin Otter Floatplanes all Series

Unsafe Condition

Loosening and subsequent pullout failure of certain float to fuselage bolts.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Comply with accomplishment instructions of de Havilland Service Bulletin 6/296, Revision A, dated May 11, 1973, or an equivalent alteration approved by 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 ten hours in service from the effective date of this Airworthiness Directive, unless already accomplished

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

de Havilland Model DHC-6 Twin Otter Floatplanes all Series, equipped with Canadian Aircraft Products Model 12000A or 12000B Floats installed prior to Float Serial No. 71.

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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