47-21-11: Firewall Stud Bushings
FAA order 47-21-11 is an airworthiness directive. The FAA's subject line: Firewall Stud Bushings. System: other and general.
What it applies to as the FAA lists it
- Kind of product
- Aircraft
- Makes
- Sky Enterprises, Inc.
- Models
- RC-3
Dates and paperwork
- 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 (425 characters)
47-21-11 REPUBLIC: (Was Mandatory Note 1 of AD-769-2.) Applies to Model RC-3 Aircraft Serial Numbers 5 to 174, Inclusive.
Compliance required prior to July 1, 1947.
In order to prevent short circuiting of terminal studs on the firewall, remove each stud, enlarge the hole (0.316 drill) and insert a bushing (P/N 17F82080-1).
(Republic Seabee Service Bulletin No. 1, dated December 18, 1946, covers this same subject.)
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/47-21-11.json · aircraft systems.