AD 78-01-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Viking Air Limited | DHC-6-1 | Airworthiness Directives; de Havilland of Canada DHC-6 Series Aircraft |
| aircraft | Viking Air Limited | DHC-6-100 | Airworthiness Directives; de Havilland of Canada DHC-6 Series Aircraft |
| aircraft | Viking Air Limited | DHC-6-200 | Airworthiness Directives; de Havilland of Canada DHC-6 Series Aircraft |
| aircraft | Viking Air Limited | DHC-6-300 | Airworthiness Directives; de Havilland of Canada DHC-6 Series Aircraft |
Unsafe Condition
Total electrical failure due to contact welding of the reverse current relay and subsequent burning of adjacent wiring, the other reverse current relay, and the battery circuit wiring.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Install de Havilland modification 6/1598 in accordance with de Havilland Service Bulletin No. 6/353 dated May 13, 1977, or later revision, or an equivalent 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 800 hours in service after the effective date of this AD unless already accomplished, or de Havilland Modification 6/1591 is incorporated
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
de Havilland of Canada DHC-6 series aircraft serial numbers 1 through 530
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Electrical Failure
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_78-01-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 78-01-05 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; de Havilland of Canada DHC-6 Series Aircraft Subject: Electrical Failure Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 02/09/1978 Make: Viking Air Limited Model: DHC-6-1 | DHC-6-100 | DHC-6-200 | DHC-6-300 Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 78-01-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-3111 AD NUMBER: 78-01-05 SUBJECT HEADING: Airworthiness Directives; de Havilland of Canada DHC-6 Series Aircraft ACTION: SUMMARY: DATES: Effective February 9, 1978. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 78-01-05 De HAVILLAND: Amendment 39-3111. Applies to de Havilland of Canada DHC-6 series aircraft serial numbers 1 through 530. Compliance required within 800 hours in service after the effective date of this AD unless already accomplished, or de Havilland Modification 6/1591 is incorporated. To preclude the possibility of total electrical failure due to contact welding of the reverse current relay and subsequent burning of the adjacent wiring, the other reverse current relay and the battery circuit wiring, install de Havilland modification 6/1598 in accordance with de Havilland Service Bulletin No. 6/353 dated May 13, 1977, or later revision, or an equivalent approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region. This amendment is effective February 9, 1978. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_78-01-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 78-01-05 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; de Havilland of Canada DHC-6 Series Aircraft Subject: Electrical Failure Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 02/09/1978 Make: Viking Air Limited Model: DHC-6-1 | DHC-6-100 | DHC-6-200 | DHC-6-300 Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 78-01-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-3111 AD NUMBER: 78-01-05 SUBJECT HEADING: Airworthiness Directives; de Havilland of Canada DHC-6 Series Aircraft ACTION: SUMMARY: DATES: Effective February 9, 1978. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 78-01-05 De HAVILLAND: Amendment 39-3111. Applies to de Havilland of Canada DHC-6 series aircraft serial numbers 1 through 530. Compliance required within 800 hours in service after the effective date of this AD unless already accomplished, or de Havilland Modification 6/1591 is incorporated. To preclude the possibility of total electrical failure due to contact welding of the reverse current relay and subsequent burning of the adjacent wiring, the other reverse current relay and the battery circuit wiring, install de Havilland modification 6/1598 in accordance with de Havilland Service Bulletin No. 6/353 dated May 13, 1977, or later revision, or an equivalent approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region. This amendment is effective February 9, 1978. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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