AD 79-14-01

final rule

Airworthiness Directives; de Havilland Aircraft of Canada, Limited, Model DHC-6 Series Twin Otter Aircraft

AD Number
79-14-01
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.
Technical illustration of an aircraft flight control surface and actuator
Problem area Flight controls

Applicability

TypeManufacturerModelDetails
aircraft Viking Air Limited DHC-6-1 Airworthiness Directives; de Havilland Aircraft of Canada, Limited, Model DHC-6 Series Twin Otter Aircraft
aircraft Viking Air Limited DHC-6-100 Airworthiness Directives; de Havilland Aircraft of Canada, Limited, Model DHC-6 Series Twin Otter Aircraft
aircraft Viking Air Limited DHC-6-200 Airworthiness Directives; de Havilland Aircraft of Canada, Limited, Model DHC-6 Series Twin Otter Aircraft
aircraft Viking Air Limited DHC-6-300 Airworthiness Directives; de Havilland Aircraft of Canada, Limited, Model DHC-6 Series Twin Otter Aircraft

Unsafe Condition

Loss of elevator control and improper operation of the elevator control system due to incorrect torque on four bolts on the aft elevator cable control quadrant.

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

Required Actions

Inspect and torque-correct four bolts on the aft elevator cable control quadrant within 100 hours in service. Perform Modification No. 6/1679 within 600 hours in service. Use approved equivalent methods if available.

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

Compliance Time

Within the next 100 hours in service after the effective date of this airworthiness directive and within 600 hours in service after the effective date.

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

Affected Aircraft

de Havilland Aircraft of Canada, Limited Model DHC-6 Series Twin Otter Aircraft, serial numbers 331 through 563 inclusive, 565 through 587 inclusive, 589 through 598 inclusive, 600, 601, 603, and 604.

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

Federal Register Abstract

Elevator Control System

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_79-14-01.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
79-14-01
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; de Havilland Aircraft of Canada, Limited, Model DHC-6 Series Twin Otter Aircraft
Subject:
Elevator Control System
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
07/06/1979
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: 79-14-01
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-3509

AD NUMBER:   79-14-01

SUBJECT HEADING:   Airworthiness Directives; de Havilland Aircraft of Canada, Limited, Model DHC-6 Series Twin Otter Aircraft

ACTION:  

SUMMARY:  

DATES:   Effective July 6, 1979.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
79-14-01 De HAVILLAND: Amendment 39-3509. Applies to DeHavilland Aircraft of Canada, Limited, Model DHC-6 Series Twin Otter Aircraft, certificated in all categories, S/N 331 through 563 inclusive, 565 through 587 inclusive, 589 through 598 inclusive, 600, 601, 603 and 604.

Compliance is required as indicated.

To preclude loss of elevator control and ensure proper operation of the elevator control system:

(a) Within the next 100 hours in service after the effective date of this airworthiness directive, unless previously accomplished, inspect the four bolts on the aft elevator cable control quadrant for correct torque and alter, as necessary, in accordance with the INSPECTION and RECTIFICATION paragraphs of ACCOMPLISHMENT INSTRUCTIONS in DeHavilland S/B No. 6/379 dated December 11, 1978, or an approved equivalent.

(b) Within 600 hours in service after the effective date of this airworthiness directive, unless already accomplished, alter in accordance with Modification No. 6/1679, noted in S/B No. 6/379, or an approved equivalent.

(c) Equivalent inspections, alterations and replacement parts must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.

(d) Upon submission of substantiating data by an owner, or operator through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region, may adjust the compliance time specified in this AD.

This amendment is effective July 6, 1979.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_79-14-01.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
79-14-01
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; de Havilland Aircraft of Canada, Limited, Model DHC-6 Series Twin Otter Aircraft
Subject:
Elevator Control System
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
07/06/1979
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: 79-14-01
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-3509

AD NUMBER:   79-14-01

SUBJECT HEADING:   Airworthiness Directives; de Havilland Aircraft of Canada, Limited, Model DHC-6 Series Twin Otter Aircraft

ACTION:  

SUMMARY:  

DATES:   Effective July 6, 1979.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
79-14-01 De HAVILLAND: Amendment 39-3509. Applies to DeHavilland Aircraft of Canada, Limited, Model DHC-6 Series Twin Otter Aircraft, certificated in all categories, S/N 331 through 563 inclusive, 565 through 587 inclusive, 589 through 598 inclusive, 600, 601, 603 and 604.

Compliance is required as indicated.

To preclude loss of elevator control and ensure proper operation of the elevator control system:

(a) Within the next 100 hours in service after the effective date of this airworthiness directive, unless previously accomplished, inspect the four bolts on the aft elevator cable control quadrant for correct torque and alter, as necessary, in accordance with the INSPECTION and RECTIFICATION paragraphs of ACCOMPLISHMENT INSTRUCTIONS in DeHavilland S/B No. 6/379 dated December 11, 1978, or an approved equivalent.

(b) Within 600 hours in service after the effective date of this airworthiness directive, unless already accomplished, alter in accordance with Modification No. 6/1679, noted in S/B No. 6/379, or an approved equivalent.

(c) Equivalent inspections, alterations and replacement parts must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.

(d) Upon submission of substantiating data by an owner, or operator through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region, may adjust the compliance time specified in this AD.

This amendment is effective July 6, 1979.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

This site is not affiliated with or endorsed by the FAA. Always verify with official sources.