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A350CN-IW-BK-LG-28 – Whelen Interior LED Post Light Assembly
Available now on the Airparts.aero Marketplace.
The A350CN-IW-BK-LG-28 is a state-of-the-art, FAA-PMA certified LED interior light assembly manufactured by Whelen Aerospace Technologies (WAT). Designed specifically for the high-end cockpits of modern business and commercial aircraft, this "Post Light" serves as a localized illumination source for primary flight instruments, engine gauges, and pedestal panels. The "IW" designation indicates an Instrument White output, providing a crisp, neutral light that enhances color contrast and legibility without the eye-strain associated with legacy incandescent bulbs.
This assembly is a "Long" (LG) variant, featuring an extended body designed to clear deeper instrument bezels or specialized panel overlays. Operating on 28V DC, the A350 series is the aviation industry standard for upgrading legacy post-lighting to high-reliability LED technology, offering a service life that often exceeds the remaining lifespan of the airframe.
Key Features
LED Efficiency & Longevity: Rated for approximately 50,000 hours of operation, virtually eliminating the "burnt-out bulb" maintenance issues common with legacy GE327 or GE330 incandescent post lights.
Instrument White (IW) Output: Engineered for superior color rendering ($CRI$), making it easier for pilots to distinguish between colored markings on analog gauges and digital displays.
"Long" Body Profile (LG): Specifically dimensioned to provide the correct light "wash" over instruments that sit recessed within the panel or behind thick anti-glare shields.
Integrated Dimming Compatibility: Designed to interface seamlessly with existing aircraft PWM (Pulse Width Modulation) or rheostat dimming circuits, providing smooth, flicker-free adjustment from $0\%$ to $100\%$ brightness.
Low Heat Signature: Unlike incandescent lights that can reach high temperatures, this LED assembly remains cool to the touch, protecting sensitive avionics and plastic panel components from thermal degradation.
Technical Specifications
Part Number: A350CN-IW-BK-LG-28, 01-0770119-12
Manufacturer: Whelen Aerospace Technologies (WAT)
Light Color: Instrument White (IW)
Housing Finish: Black (BK)
Length Type: Long (LG)
Operating Voltage: 28V DC
Current Draw: Significantly lower than incandescent equivalents (approx. 0.02 Amps)
Certification: FAA-PMA
Mounting: Standard 5/16-32 threaded post
Also Listed As: A350CN-IWBKLG-28, A350CN-IW-BK-LG28
Aircraft Compatibility
Business Jets: Bombardier Learjet, Challenger, and Global series; Cessna Citation series.
Turboprops: Beechcraft King Air (all models), Pilatus PC-12, and SOCATA TBM.
Modernized GA: High-performance singles such as the Beechcraft Bonanza and Cessna Centurion.
Note: The A350 series is a popular "drop-in" replacement for older Grimes or Hella post lights. Always verify the total panel "stack-up" thickness to ensure the "Long" (LG) version provides the optimal light angle for your specific instrument layout.
Applications
The A350CN-IW-BK-LG-28 is utilized for Secondary Flight Deck Illumination. Its primary roles include:
Instrument "Wash" Lighting: Providing indirect light across the face of primary flight instruments for night operations.
Circuit Breaker Panel Lighting: Ensuring clear visibility of breaker labels in darkened cockpit environments.
Pedestal & Console Lighting: Illuminating trim wheels, fuel selectors, and environmental control knobs.
Why Choose A350CN-IW-BK-LG-28?
Choosing the Whelen A350CN-IW-BK-LG-28 is a strategic move for Dispatch Reliability. A single failed post light can technically ground an aircraft for night VFR or IFR operations depending on the Minimum Equipment List (MEL). By transitioning to LED, operators significantly reduce the probability of a "Dark Cockpit" AOG. The "Instrument White" color is specifically balanced to maintain the pilot's Mesopic Vision (night adaptation) more effectively than the "yellowish" tint of traditional bulbs, directly contributing to flight safety during the critical approach and landing phases.
The A350CN-IW-BK-LG-28 functions as a Point-Source Illuminator governed by the Inverse Square Law ($E = I / d^2$). Because the "Long" (LG) body increases the distance ($d$) from the base to the light source, it allows the light to "reach over" structural obstructions on the panel. The LED utilizes a Constant Current Driver to ensure that even if the aircraft's bus voltage fluctuates during high-load events (like gear extension), the light output remains perfectly steady, preventing the distracting "flicker" often seen in cheaper automotive-grade LED retrofits.
Note: This is a certified aircraft lighting component. Installation should be performed by an FAA-certified A&P or avionics technician. Ensure the 28V polarity is correctly observed during wiring, as LEDs are semi-conductor devices. If replacing incandescent bulbs, verify that your dimmer system is compatible with LED loads; some older rheostats may require a small load resistor to achieve full dimming range.
