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50-430061-27 – Textron Aviation OEM Door Seal Assembly
Part Number: 50-430061-27
Manufacturer: Textron Aviation (Beechcraft)
Common Synonyms: Cabin Door Pressure Seal, Inflatable Door Seal, P-Seal Assembly
Overview Section
The 50-430061-27 is an authentic Textron Aviation OEM cabin door seal assembly designed for the Beechcraft King Air and Beech 1900 series.1 This is a primary pressure-containment component that ensures the structural and pneumatic integrity of the aircraft’s pressurized cabin.
Unlike standard static seals, the 50-430061-27 is often a complex, multi-layered extrusion designed to interface with the aircraft's bleed air or passive inflation system. It is engineered to provide a 100% airtight barrier between the moveable cabin door and the fuselage frame, maintaining the cabin altitude required for passenger safety and comfort at flight levels up to FL350.
Enhanced Technical Data
| Technical Metric | Specification Data |
| Material Base | Reinforced Silicone Elastomer / Fabric-Reinforced Neoprene |
| Profile Type | Specialized "P-Bulb" with Integrated Mounting Flange |
| Operating Temperature | $-65°F$ to $+400°F$ ($-54°C$ to $+204°C$) |
| Pressure Differential | Rated for $\Delta P$ of 6.6 PSI (Standard King Air max) |
| Tensile Strength | > 950 PSI |
| Elongation | 300% (allows for door expansion under pressure) |
| Fluid Resistance | Resistant to Type IV De-icing fluid, Skydrol, and Ozone |
| Certification | FAA-PMA / OEM |
Advanced Engineering & Structural Application
The 50-430061-27 is engineered for Hysteresis Resistance. In pressurized aircraft, the cabin door "cycles" with every flight—expanding as the aircraft climbs and contracting as it descends. The seal must be capable of following this structural movement without losing contact with the sealing surface.
Engineering Insight: Acoustic and Thermal Insulation
Beyond pressure containment, this seal assembly acts as a critical Acoustic Dampener. Any gap in the 50-430061-27 will manifest as a high-pitched "whistle" or "wind roar" in the cockpit. The density of the reinforced silicone is calibrated to absorb high-frequency aerodynamic noise. Additionally, it serves as a thermal barrier, preventing the $-50°C$ ambient air at altitude from cooling the cabin door frame to the point of condensation or frost buildup inside the cabin.
Aircraft Compatibility
The 50-430061-27 is a high-level assembly found in the Illustrated Parts Catalog (IPC) for:
Beechcraft King Air 200 Series: B200, B200GT, 250, 260.
Beechcraft King Air 300 Series: 300, B300 (350), 350i, 360.
Beechcraft 1900 Series: 1900C and 1900D Airliners.
Beechcraft Duke (60 Series): Utilized in certain pressurized door configurations.
The Textron Aviation 50-430061-27 represents the pinnacle of environmental sealing for the Beechcraft turboprop fleet. When your mission profile involves high-altitude flight, the reliability of your cabin door seal is non-negotiable. This OEM assembly is manufactured to the exact tolerances of the King Air airframe, providing a seamless fit that aftermarket seals cannot replicate. By choosing the 50-430061-27, you ensure maximum pressurization efficiency, reduced fuel burn (due to lower bleed air demand), and a significantly quieter cabin for your passengers.
Installation & Maintenance Addendum
Grommet and Retainer Check: Before installation, inspect the door frame retainer channel for nicks or burrs. A sharp edge in the metal track will slice the 50-430061-27 during the first pressurization cycle.
Adhesive and Lubrication: Use only 3M 1300L or specified Beechcraft adhesives on the mounting flange. Once installed, a light application of Talcum Powder or a specialized dry-film lubricant is recommended to prevent the seal from sticking to the door frame during hot/humid operations.
Pressure Decay Test: Following installation, a Cabin Pressure Decay Test must be performed per the Aircraft Maintenance Manual (AMM) to ensure the leak rate is within airworthy limits (typically not exceeding a specific PSI drop over 1 minute).
