# AD 79-14-01: Elevator Control System

- Type: Airworthiness directive
- Status: Current
- Products: Viking Air DHC-6-1, DHC-6-100, DHC-6-200 and DHC-6-300
- Effective: July 6, 1979
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-3509
- Registered aircraft: 88 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/9A0E84D6ED0D741186256A38004C3CF0.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/79-14-01

## The airworthiness directive

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.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A9EA](https://openairdocs.org/tcds/A9EA): De Havilland Aircraft of Canada Limited; names 4 of 5 models: DHC-6-1, DHC-6-100, DHC-6-200, DHC-6-300

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 88 (88 by airframe model, 0 by engine model)
- Makers: Dehavilland 84, Dehavilland Acft Of Canada 4

Models with the most aircraft:

- [Dehavilland DHC-6-300](https://openairdocs.org/model/dehavilland-dhc-6-300): 59 aircraft (airframe model)
- [Dehavilland DHC-6-200](https://openairdocs.org/model/dehavilland-dhc-6-200): 19 aircraft (airframe model)
- [Dehavilland DHC-6-100](https://openairdocs.org/model/dehavilland-dhc-6-100): 6 aircraft (airframe model)
- [Dehavilland Acft Of Canada DHC 6-300](https://openairdocs.org/model/dehavilland-acft-of-canada-dhc-6-300): 4 aircraft (airframe model)

All 4 models: https://openairdocs.org/ad/79-14-01/models.md
Every aircraft: https://openairdocs.org/ad/79-14-01/aircraft.md

Its text cites no advisory circulars or STCs.

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