- Effective
- July 6, 1979
- Models
- DHC-6-1, DHC-6-100, DHC-6-200, DHC-6-300
- Data sheet
- TCDSA9EA
- Registered aircraft
- 88 matched by model
- Product
- Aircraft · Small airplane
- Amendment
- 39-3509
Unofficial copy of the text in the FAA’s Dynamic Regulatory System. The FAA’s own copy is the authoritative one. DRS record last changed May 30, 2024.
Copies of the files this page was built from, with their SHA-256. Retrieved October 18, 2026.
| File | Size | SHA-256 | Original |
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On this page
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 TCDS · 1
The type certificate data sheets for the models this AD names, matched by model and maker.
Registered aircraft · 88
Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.
| 1966 | 1 |
|---|---|
| 1967 | 5 |
| 1968 | 7 |
| 1969 | 11 |
| 1970 | 2 |
| 1971 | 1 |
| 1973 | 3 |
| 1974 | 6 |
| 1975 | 1 |
| 1976 | 4 |
| 1977 | 6 |
| 1978 | 1 |
| 1979 | 3 |
| 1980 | 5 |
| 1981 | 3 |
| 1982 | 1 |
| 1984 | 1 |
| 1985 | 2 |
25 with no year recorded