47-21-05: Propeller Control Friction Lock
FAA order 47-21-05 is an airworthiness directive. The FAA's subject line: Propeller Control Friction Lock. System: propeller.
What it applies to as the FAA lists it
- Kind of product
- Aircraft
- Makes
- Sierra Hotel Aero, Inc.
- Models
- Navion (Army L-17A)
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 (367 characters)
47-21-05 NAVION: (Was Mandatory Note 4 of AD-782-3.) Applies to Serial Numbers NAV-4-11 Through 21 and 44 Through 47.
To be accomplished not later than August 1, 1947.
Replace the original propeller control with one that incorporates a positive friction lock in accordance with NAA Kit Drawing 145-89011.
(NAA Field Service Bulletin No. 5 covers this change.)
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/47-21-05.json · aircraft systems.