| AD Number | 87-25-02 | Status | Active |
| Effective Date | December 31, 1987 | Issue Date | Not specified |
| Docket Number | Unknown | Amendment | 39-5778 |
| Product Type | ["Aircraft"] | Product Subtype | ["Rotorcraft"] |
| CFR Part | --- - Part 39 | CFR Section | N/A |
| Citation | This information is not available. | ||
| Manufacturer(s) | Sikorsky Aircraft Corporation |
| Model(s) | S-76A S-76B |
87-25-02 SIKORSKY AIRCRAFT: Amendment 39-5778. Applies to all Model S-76A and S-76B series helicopters through and including serial number 760350, certified in any category.
Compliance is required within the next 25 hours' time in service after the effective date of this AD, unless already accomplished.
To prevent possible loss of AC electrical power due to 26 VAC transformer single ground connection failure, provide separate ground connections for 26 VAC transformers 1 and 2.
NOTE: Sikorsky Service Bulletin No. 76-24-5, AC Electrical Power System - AC Power Transformer Ground Wires Termination-Separation of, dated October 19, 1987, constitutes an acceptable means of compliance with this requirement.
This amendment becomes effective December 31, 1987.