S2243-2 – Textron Aviation OEM Red Incandescent Indicator Lamp
Available now on the Airparts.aero Marketplace.
Overview
The S2243-2 is a genuine Textron Aviation (Cessna) Original Equipment Manufacturer (OEM) incandescent indicator lamp, engineered for specific annunciation or illumination applications within the cockpit.1 This component is designed to produce a distinct red light, typically serving as a visual alert for system status warnings or cautions. As a traditional incandescent lamp, it generates light through the heating of a tungsten filament within a sealed glass envelope.
Manufactured to the precise specifications of Textron's engineering drawings, the S2243-2 ensures the correct voltage rating, physical dimensions (including base type), light output intensity, and color rendering required for its designated function. While modern LED technology offers longer life, incandescent lamps like the S2243-2 remain specified components in many certified aircraft panels, and using the correct OEM part is essential for maintaining the integrity and certifiability of those systems.
Key Features
Genuine Textron Aviation OEM Part: Guarantees the lamp is the factory-specified and fully certified component, ensuring correct electrical characteristics and fit.
Incandescent Filament Technology: Provides a reliable light source using proven tungsten filament technology.
Red Light Output: Engineered with a specific coating or internal filter to produce aviation red light for warning, caution, or specific illumination purposes.
Designed for Specific Aircraft Systems: Meets the exact voltage, wattage, base type, and brightness requirements for its intended application in Textron aircraft panels.
Vibration Resistant: Constructed to withstand the vibrational environment typical of aircraft instrument panels.
Technical Specifications
Part Number: S2243-2
Component Type: Incandescent Indicator Lamp
OEM Authority: Textron Aviation (Cessna)
Light Color: Aviation Red
Technology: Incandescent (Tungsten Filament)
Base Type: Must be confirmed by Textron Aviation documentation (e.g., T-1 3/4 Midget Flange, Bi-Pin).
Voltage Rating: Must be confirmed by Textron Aviation documentation (e.g., 14 VDC or 28 VDC).
Wattage / Amperage: Per Textron Aviation Engineering Drawing S2243.
Governing Specification: Textron Aviation Engineering Drawing S2243.
Aircraft Compatibility
This OEM incandescent lamp is specified for use in various indicator panels and lighting fixtures on a wide range of Textron Aviation (Cessna) aircraft.
Representative Cessna Platforms:
Cessna Piston Aircraft (100, 200, 300, 400 Series)
Cessna Caravan Series
Certain applications in legacy Cessna Citation business jets.
Note: Verification of applicability is the absolute responsibility of the installer. The aircraft's current Illustrated Parts Catalog (IPC) for its specific serial number is the final authority for confirming part number eligibility for a specific lamp socket.
Applications
Annunciator panel warning and caution lights.
Status indicator lights for systems like landing gear, flaps, or doors.
Panel backlighting or post lighting where red illumination is specified.
Why Choose S2243-2?
Indicator lamps in an aircraft cockpit are critical for crew situational awareness. The genuine Textron OEM S2243-2 is the only lamp guaranteed to have the correct voltage rating (preventing instant burnout or dim illumination), the specified base type for a secure fit, the correct color rendering for unambiguous annunciation, and the appropriate brightness level. Using a generic or automotive bulb introduces significant risks, including incorrect indications, premature failure, or even damage to the lamp socket or associated wiring due to mismatched electrical characteristics.
The S2243-2 operates on the fundamental principle of incandescence: generating light by heating a material to a high temperature.3 Inside the hermetically sealed glass envelope (filled with an inert gas like argon to retard filament evaporation), a fine tungsten filament is suspended. Tungsten is chosen for its extremely high melting point (3422°C) and favorable electrical resistance.4 When electrical current passes through the filament, Joule heating ($P = I^2R$) rapidly raises its temperature to typically between 2200°C and 2700°C. At these temperatures, the filament emits thermal radiation across a broad spectrum, described by Planck's law of black-body radiation. A significant portion of this energy falls within the visible spectrum, producing light. To achieve the specific red color, the S2243-2's glass envelope is either manufactured using red glass or coated with a durable, heat-resistant red lacquer that acts as an optical filter, selectively transmitting wavelengths in the red portion of the spectrum while absorbing others.
Note: This is an electrical component. Installation must be performed by a certified A&P mechanic or avionics technician. Ensure the replacement lamp has the exact same voltage rating as the circuit requires (typically 14V or 28V). Handle the glass bulb carefully, avoiding contact with bare skin if possible, as oils can potentially shorten lamp life when heated. Verify proper operation after installation.
Documentation
No public-facing OEM or regulatory documentation was located for this specific part number. All technical data, including voltage, wattage, and base type for the S2243-2 lamp, are proprietary to Textron Aviation. This information is contained within the official Maintenance Manual, Wiring Diagram Manual, and Illustrated Parts Catalog for the applicable aircraft model.