- Effective
- February 9, 1978
- 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
- 39-3111
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 |
|---|---|---|---|
| FAA DRS HTML | 19 KB | 69e5022a…e08adf3 | FAA DRS (API key needed) |
On this page
The airworthiness directive
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.
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