58-02-03: Carburetor Mixture Control Removal
FAA order 58-02-03 is an airworthiness directive. The FAA's subject line: Carburetor Mixture Control Removal. It names Hiller UH-12: about 217 aircraft on the U.S. register today, though an order usually covers particular versions or serial numbers rather than every one. System: engine.
What it applies to as the FAA lists it
- Kind of product
- Aircraft
- Makes
- Hiller Aviation
- Models
- UH-12, UH-12A, UH-12B, UH-12C, UH-12D
- On this site
- Hiller UH-12 217 registered
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 (1,229 characters)
58-02-03 HILLER: Applies to UH-12 Series Helicopters Equipped With Marvel- Schebler Automatic Altitude Compensating Carburetor Model MA-4-5AA (Aircooled P/N 19588).
Compliance required by June 1, 1958.
With a Marvel-Schebler Model MA-4-5AA carburetor installed, it is possible to start and run the engine with the carburetor mixture control in the idle cutoff position if the throttle is partially or fully opened. However, as soon as the throttle is fully closed, the idle cutoff will operate and shut off the engine. Therefore, it would be possible to start the engine, take off, and fly with the mixture in idle cutoff, as long as the throttle is never closed. The first time the throttle is closed, however, as in autorotation, an immediate engine stoppage would occur.
To prevent inadvertent engine stoppage in flight due to failure to place the carburetor mixture control in the "ALT.COMP" position before takeoff, the following measure is necessary:
Delete the carburetor mixture control from the cockpit and secure the carburetor setting at "ALT.COMP" at the carburetor.
Hiller will issue a service bulletin covering this subject. Appropriate FAA approved Helicopter Flight Manual revision required.
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/58-02-03.json · aircraft systems.