S1899-1 – Textron Aviation Indicator Light Assembly (Red Lens)
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The S1899-1 is a genuine Textron Aviation (Cessna) OEM indicator light assembly. This component is typically utilized as a general-purpose warning or status indicator light on the instrument panel or annunciator panel of various Cessna aircraft. Featuring a red lens, its function is usually associated with alerting the pilot to a specific system condition that requires attention or signifies a potential operational issue.
This is a robust, aviation-grade assembly designed for panel mounting. It consists of the lamp holder body, a colored lens cap (red for this part number), and utilizes a replaceable incandescent bulb (sold separately) appropriate for the aircraft's electrical system voltage. The reliability of this indicator is important for ensuring the pilot receives timely visual cues regarding the status of critical aircraft systems.
Key Features
Genuine Textron Aviation OEM Part: Guarantees the correct fit, color, voltage compatibility, and material standards for the aircraft's indicating system.
Red Lens for Warning Indication: The red color is universally recognized in aviation cockpits to signify a warning or caution condition requiring pilot awareness.
Panel Mount Design: Engineered for secure installation in the aircraft's instrument or annunciator panel.
Replaceable Bulb Design: Allows for the easy replacement of the internal incandescent bulb without replacing the entire assembly, simplifying maintenance.
Durable Construction: Built with high-quality materials to withstand the vibration and environmental conditions of the cockpit.
Technical Specifications
Part Number: S1899-1
Component Type: Indicator Light Assembly / Annunciator
OEM Manufacturer: Textron Aviation (Cessna)
Lens Color: Red
Lamp Type: Requires replaceable incandescent bulb (e.g., T-1 3/4 midget flange base), voltage dependent on aircraft system (14V or 28V). Bulb typically sold separately.
Mounting Style: Panel mount, likely with threaded body and retaining nut.
Aircraft Compatibility
The S1899-1 is a standard indicator light used across a wide range of Textron Aviation (Cessna) aircraft, often serving various functions depending on the specific model and panel configuration. Common applicable models include, but are not limited to:
Cessna 152
Cessna 172 Skyhawk
Cessna 182 Skylane
Cessna 206 Stationair
Cessna 210 Centurion
Crucial Note: The specific application (e.g., low vacuum warning, pitot heat on, etc.) and installation eligibility for a particular aircraft model and serial number must be verified using the latest revision of the official Textron Aviation (Cessna) Illustrated Parts Catalog (IPC) and Wiring Diagram Manual.
Applications
The specific function of this red indicator light varies by aircraft model and installation. Common applications include:
Low Vacuum System Warning
Pitot Heat ON Indication
Stall Warning System Test Indication
Other Cautionary or Warning Annunciations as defined by the aircraft's POH/AFM.
Why Choose S1899-1?
Choosing the genuine Textron S1899-1 ensures you are installing an indicator light that meets the original factory specifications for brightness, color, and electrical compatibility. Using non-certified or incorrect indicator lights can lead to confusion in the cockpit, failure to properly annunciate a critical condition, or electrical system issues. The OEM part guarantees correct function and integration with the aircraft's systems, ensuring reliable visual feedback for the pilot.
The S1899-1 assembly is designed to house a miniature incandescent lamp, typically a T-1 3/4 midget flange base bulb. These bulbs operate on the principle of incandescence, where electrical current (1$I$) passes through a high-resistance tungsten filament (2$R$).3 According to Joule's first law, the power dissipated as heat is 4$P = I^2R$.5 This intense heat raises the filament's temperature to over 2700 Kelvin, causing it to glow brightly and emit a broad spectrum of electromagnetic radiation, peaking in the visible and near-infrared range. The colored lens cap acts as an optical filter, selectively transmitting only the red wavelengths of light while absorbing others, resulting in the required red indication. The choice of incandescent technology, while older, is often retained in certified aircraft for its proven reliability, resistance to certain types of electrical noise, and predictable failure mode (typically an open circuit when the filament breaks), which is easily detectable via a press-to-test circuit.
Note: This is a component of the aircraft's indicating and warning system. Proper function is important for pilot situational awareness. Ensure the correct voltage bulb is installed for the specific aircraft electrical system (14V or 28V). Bulb integrity should be checked during pre-flight using the press-to-test function if available or as part of routine panel checks. All electrical work must be performed by a certified A&P or avionics technician.
Documentation
The definitive part number applicability, associated bulb part number, and installation procedures are detailed in the applicable Textron Aviation (Cessna) Illustrated Parts Catalog (IPC), Maintenance Manual, and Wiring Diagram Manual for the specific aircraft model and serial number.