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0813074-12 – Textron Aviation OEM WEMAC Adapter Assembly
Available now on the Airparts.aero Marketplace.
The Textron Aviation 0813074-12 is an OEM-certified adapter assembly designed to interface "WEMAC" style cabin air vents and overhead lights with the aircraft's Environmental Control System (ECS) ducting. Manufactured specifically for the Textron fleet—primarily Cessna Citation and Beechcraft King Air series—this adapter is the critical mechanical link that secures the iconic "eyeball" vent or cabin light housing to the interior panels and the SCAT/SCEET air supply hoses.
The WEMAC (West Coast Electrical Manufacturing Company) standard is the aerospace industry benchmark for adjustable cabin ventilation. The 0813074-12 adapter ensures that high-velocity conditioned air is delivered directly to the vent without leakage into the overhead plenum, which would otherwise reduce cooling efficiency and potentially introduce "pantry" smells or particulates from the cabin crown into the airflow. For maintenance crews, this assembly provides a rigid, vibration-resistant mount that allows for the rapid removal and replacement of the vent or light units during interior refurbishments or system servicing.
Key Features
Precision Duct Interface: Features a ribbed or flanged neck designed to provide a secure, air-tight grip for 2-inch or 2.5-inch diameter SCAT/SCEET ducting.
Non-Marring Mounting: Engineered with a specific flange geometry that distributes clamping pressure evenly against the cabin headliner or side panels, preventing cracking of delicate interior finishes.
Aerospace-Grade Composite/Alloy: Fabricated from high-impact, fire-retardant materials that comply with FAR 25.853 flammability requirements for cabin interiors.
Anti-Rattle Design: Includes integrated gaskets or tight-tolerance seating to eliminate harmonic vibrations and "whistling" often associated with high-velocity airflow in cabin vents.
OEM Fitment: Guarantees perfect alignment with WEMAC 1871 or 2120 series air valves, ensuring the "eyeball" swivels freely without binding against the adapter housing.
Technical Specifications
Part Number: 0813074-12
Manufacturer: Textron Aviation (Cessna / Beechcraft)
Component Type: WEMAC Vent/Light Adapter Assembly
Material: Flame-retardant polymer or Anodized Aluminum (Application dependent)
Compatibility: Designed for WEMAC-style eyeball vents and cabin lights
Flammability Rating: Compliant with FAR 25.853
Duct Size: Typically 2.0" or 2.5" ID
Governing Specifications: Textron Engineering Standard 08-series
Certification: FAA-PMA / Textron OEM Standard Hardware
Aircraft Compatibility
Cessna Citation Series: 500, 525 (CJ), 550, 560 (Excel/XLS), and 650.
Beechcraft King Air Series: 90, 200, and 300 series models.
Cessna Caravan: 208 and 208B (Passenger configurations).
Beechcraft Premier I / IA: 390 series.
Note: The 0813074-12 is frequently used in overhead "gasper" units. Always verify the specific station number in the Illustrated Parts Catalog (IPC) to ensure correct interior color and trim matching.
Applications
Cabin Ventilation (Gasper) Systems: Providing the transition point between flexible air ducts and passenger eyeball vents.
Overhead Lighting Pods: Serving as the mounting chassis for directional reading lights.
ECS Refurbishment: Replacing brittle or cracked legacy adapters to restore cabin airflow velocity and reduce noise.
Why Choose 0813074-12?
In a pressurized cabin, the Environmental Control System (ECS) relies on maintaining specific back-pressures to ensure balanced airflow across all passenger rows. Utilizing generic or aged adapters that have "cold-flowed" or cracked leads to significant static pressure loss. This results in the "hot row" phenomenon, where some passengers receive no airflow while others are over-cooled. The 0813074-12 is engineered to maintain its dimensional stability across the extreme temperature cycles of the aircraft cabin, ensuring that the Venturi Effect intended by the original designers is preserved for maximum passenger comfort.
The 0813074-12 functions on the principle of Sealed Path Ventilation. In a modern ECS, air is delivered at a slightly higher pressure than the cabin ambient. The adapter acts as a plenum transition, converting the turbulent flow from the flexible ducting into a more laminar flow before it enters the WEMAC air valve. This reduces the Reynolds Number at the vent interface, which is the primary method for decreasing "wind noise" in the passenger's ear.
Furthermore, the materials used in the 0813074-12 are selected for their Low Outgassing properties. In the event of a cabin fire, interior components must not produce toxic smoke or excessive heat release. This OEM part is tested to meet the strict "Heat Release and Smoke Density" requirements of Appendix F to Part 25, a level of safety that generic industrial adapters cannot guarantee.
Note: The 0813074-12 is an interior trim and air management component. During installation, avoid over-tightening the retaining screws, which can "dimple" or crack the headliner panel. Always ensure the SCAT ducting is secured with a high-quality stainless steel worm-gear clamp or specialized zip-tie to prevent the duct from slipping off behind the panel. Installation should be performed by an A&P mechanic or interior specialist.
