87-25-02: Ground Connections
FAA order 87-25-02 is an airworthiness directive in force since December 31, 1987. The FAA's subject line: Ground Connections. It names Sikorsky Aircraft Corp S-76: about 34 aircraft on the U.S. register today, though an order usually covers particular versions or serial numbers rather than every one. System: other and general.
What it applies to as the FAA lists it
- Kind of product
- Aircraft
- Makes
- Sikorsky Aircraft Corporation
- Models
- S-76A, S-76B
- On this site
- Sikorsky Aircraft Corp S-76 34 registered
Dates and paperwork
- In force since
- December 31, 1987
- Docket
- Unknown
- Status
- Current
- The FAA's document
- Read the order on the FAA's site
The order itself the regulatory text, as published
Show the full text (778 characters)
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.
Related safety bulletins advice on the same designs, not orders
2020-06-22AIR-20-11 · Attitude and Direction Data System, Incorrect AHRS Yaw Rate Output
2008-07-22SW-08-37 · Inoperative Cyclic Control Stick Guard
2005-12-16SW-06-15 ·
Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of November 6, 2026. Connections as data: /graph/directive/87-25-02.json · aircraft systems.