| AD Number | 64-06-07 | Status | Active |
| Effective Date | March 07, 1964 | Issue Date | Not specified |
| Docket Number | Unknown | Amendment | N/A |
| Product Type | ["Aircraft"] | Product Subtype | ["Rotorcraft"] |
| CFR Part | --- - Part 39 | CFR Section | N/A |
| Citation | This information is not available. | ||
| Manufacturer(s) | Columbia Helicopters, Inc. |
| Model(s) | 107-II |
64-06-07 VERTOL: Amdt. 697 Part 507 Federal Register March 7, 1964. Applies to All Model 107-II Helicopters.
Compliance required within 25 hours' time in service after the effective date of this AD.
To prevent recurrence of a serious lurching condition which has been encountered on this model helicopter, modify each stability augmentation system to derive a.c. power from its respective generator instead of the essential bus, as follows:
Remove the present a.c. electrical circuit wiring from terminals A3 and B3 of the a.c. instrument relay and from the "B" phase of the a.c. bus. Connect terminals A3 and B3 of the instrument relay to the terminal T2 of the a.c. feeder relay No. 1 and a.c. feeder relay No. 2 respectively.
(Vertol 107-II Service Bulletin No. 107-118 dated December 6, 1963, covers the same subject.)
This directive effective March 7, 1964.