?unique=6f422a0)
30-2481-3 – Honeywell Grimes Rear Position Navigation Light Assembly
Available now on the Airparts.aero Marketplace.
The 30-2481-3 is a flight-critical, FAA-TSO certified rear position (tail) navigation light assembly designed for a wide range of business, commercial, and general aviation aircraft. Originally engineered by Grimes Aerospace (now a division of Honeywell), this assembly is a primary component of the aircraft’s external lighting system. Its function is to provide a steady white light visible from the rear of the aircraft, ensuring compliance with FAR 91.209 for night operations and anti-collision signaling.
Constructed with a rugged, polished aluminum housing and a high-transmittance clear glass or acrylic lens, the 30-2481-3 is built to withstand the high-vibration environment of the aircraft tail cone or vertical stabilizer. The "white" output is precisely calibrated to meet the chromaticity and intensity requirements of TSO-C30c, ensuring the aircraft's orientation is unmistakable to other pilots in dark or low-visibility conditions.
Key Features
Precision Optical Lens: Features a heat-resistant, clear lens designed to provide a specific $140^\circ$ horizontal light distribution (70° to either side of the aft longitudinal axis).
Environmentally Sealed Housing: The assembly is gasketed to prevent the ingress of moisture, salt spray, and combustion byproducts (exhaust soot), ensuring the electrical contacts remain corrosion-free.
Streamlined Aerodynamic Profile: Designed with a low-drag "teardrop" or "flush-mount" geometry (depending on the specific airframe adapter) to minimize parasitic drag at high cruise speeds.
Vibration-Isolated Internal Mount: The bulb socket is often spring-loaded or cushioned to protect the filament from the harmonic vibrations common in the tail sections of piston and turbine aircraft.
Standardized Electrical Interface: Utilizes a standard two-wire or single-wire airframe ground connection, allowing for rapid replacement during line maintenance.
Technical Specifications
Part Number: 30-2481-3
Manufacturer: Honeywell / Grimes Aerospace
Component Type: Rear Position (Tail) Navigation Light
Light Color: Aviation White
Operating Voltage: 28V DC (Standard) / Compatible with 14V systems (Verify Bulb)
Lamp Type: Typically uses a Bayonet-base (e.g., MS25309-7512) or Halogen equivalent.
Material: Anodized Aluminum Housing / Tempered Glass Lens
Certification: TSO-C30c (Type III)
Compliance: FAR Part 23, 25, 27, and 29
Aircraft Compatibility
Business Jets: Bombardier Learjet, Cessna Citation, Hawker/Beechcraft series.
General Aviation (GA): High-end variants of Beechcraft King Air, Baron, and Bonanza.
Regional Turboprops: ATR 42/72 and De Havilland Dash 8.
Note: The 30-2481-3 is a "Rear" configuration. While the housing may look similar to wing-tip lights, the internal reflector and lens are specific to the aft-facing $140^\circ$ sector. Always consult the Illustrated Parts Catalog (IPC) Section 33-40 for your airframe.
Applications
The 30-2481-3 is utilized for Legal Night Navigation and Collision Avoidance. Its primary roles include:
Night Flight Compliance: Providing the mandatory white tail light required for flight between sunset and sunrise.
Spatial Orientation: Allowing other pilots to determine if they are "overtaking" your aircraft (seeing only white) versus "converging" (seeing red or green).
Ground Safety: Enhancing visibility while taxiing on dark ramps or active runways.
Why Choose 30-2481-3?
Choosing a genuine Honeywell Grimes 30-2481-3 ensures Photometric Integrity. Non-certified LED or "look-alike" assemblies often fail to meet the specific Candela (light intensity) requirements at the edges of the $140^\circ$ viewing envelope. A dim or improperly focused tail light makes the aircraft appear further away than it actually is, creating a significant mid-air collision risk. The 30-2481-3 lens is specifically treated to resist "pitting" and "yellowing" from UV exposure, ensuring the light remains "Aviation White" for its entire service life.
The 30-2481-3 functions as an Optical Signaling Device governed by the physics of Luminous Intensity. In accordance with Lambert’s Cosine Law, the reflector within the 30-2481-3 is shaped to ensure that the light intensity ($I$) does not fall below the mandatory minimum candela at the extreme angles of the $140^\circ$ rear sector. The "Aviation White" color is achieved through a specific Color Temperature (typically 2850K for incandescent or 6000K for LED retrofits) that ensures the light is distinguishable from stars or ground lights. This precision is vital for the Pilot’s Perspective; the relative movement of this specific white light against the horizon is what allows other crews to calculate closure rates and maintain safe separation.
Note: This is a flight-critical exterior lighting component. Installation must be performed by a certified A&P/AME. Prior to flight, the lens must be inspected for cracks or "crazing" that could diffuse the light beam. Ensure the assembly is properly grounded to the airframe to prevent EMI (Electromagnetic Interference) with navigation radios. When replacing bulbs, do not touch the glass with bare fingers, as skin oils can cause "hot spots" and premature lamp failure.
