AD 71-16-01

final rule
Data completeness: 70%

Airworthiness Directives; de Havilland Model DHC-6 Series Aircraft

AD Number
71-16-01
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 Series Aircraft
aircraft Viking Air Limited DHC-6-100 Airworthiness Directives; de Havilland Model DHC-6 Series Aircraft
aircraft Viking Air Limited DHC-6-200 Airworthiness Directives; de Havilland Model DHC-6 Series Aircraft
aircraft Viking Air Limited DHC-6-300 Airworthiness Directives; de Havilland Model DHC-6 Series Aircraft

Unsafe Condition

Separation of the flapper valve seal in fuel cells No. 4 and No. 5 could cause engine flameout due to fuel starvation.

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

Required Actions

Replace No. 4 and No. 5 flapper valve assemblies, P/N C6PF1026-3, with new like parts and repeat replacement every 12 months until DHC modification 6/1406 is incorporated per Service Bulletin 6/269 or an approved equivalent.

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

Compliance Time

Within 30 days after the effective date of this AD for aircraft with 12 months or more service from first flight; within 30 days after accumulating 12 months' service for those with less.

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

Affected Aircraft

de Havilland Model DHC-6 Series Aircraft, Serial Numbers 1 through 299 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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