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50-430182-5 – Textron Aviation OEM Threshold Seal
Available now through the AirParts Aero marketplace.
Overview Section
The 50-430182-5 is an authentic Textron Aviation OEM (Original Equipment Manufacturer) threshold seal, specifically designed for the entrance and utility doors of the Beechcraft King Air and 1900 series aircraft. This seal serves as a critical environmental and acoustic barrier at the base of the cabin door frame.
Engineered to withstand heavy foot traffic during boarding and the significant pressure differentials of high-altitude flight, the 50-430182-5 ensures a pressurized seal while preventing the ingress of moisture, dirt, and runway debris. As an OEM component, it meets the exact material density and compression set requirements mandated by the aircraft's Type Certificate.
Key Features Section
Aviation-Grade Elastomer: Manufactured from a specialized rubber compound that maintains flexibility at extreme temperatures ($-65°F$ at altitude to $+120°F$ on the ramp).
Precision Profile: Contoured specifically to fit the King Air threshold plate, ensuring uniform compression when the "Airstair" or cabin door is latched.
Acoustic Insulation: Significantly reduces "wind whistle" and ambient engine noise by eliminating gaps at the bottom of the door assembly.
Fluid Resistance: Resistant to common aviation fluids, including de-icing chemicals, Skydrol, and jet fuel, which often accumulate near cabin entrances.
Durability: Features a reinforced wear surface to prevent tearing or "scuffing" as passengers and crew step over the threshold.
OEM Fitment: Unlike aftermarket "universal" seals, this part requires no trimming or modification to achieve a pressurized seal.
Technical Specifications Section
| Specification | Detail |
| Part Number | 50-430182-5 |
| Manufacturer | Textron Aviation (Beechcraft) |
| Material | Reinforced Synthetic Elastomer |
| Application | Cabin/Threshold Door Seal |
| Color | Black |
| Certification | FAA-PMA / OEM |
Aircraft Compatibility Section
The 50-430182-5 is the primary threshold seal for the following Textron Aviation models:
Beechcraft King Air 90 Series: C90, E90, F90, and GT models.
Beechcraft King Air 200 Series: B200, B200GT, and 250.
Beechcraft King Air 300/350 Series: 300, B300 (350), and 350i.
Beechcraft 1900 Airliner: 1900C and 1900D utility and passenger configurations.
Technical Applications & Safety
The threshold seal is a vital component of the aircraft's Pressurization System. A compromised seal at the bottom of the cabin door can lead to the inability of the aircraft to maintain a "cabin altitude," resulting in a mandatory descent or an emergency oxygen deployment.
Safety Warning: Seal Integrity Check. During pre-flight or scheduled inspections, check the 50-430182-5 for "crushing," "dry rot," or "permanent set." If the seal does not "spring back" when the door is opened, it may fail to seal under pressure. Additionally, ensure the threshold area is clean; sand or grit trapped under the seal can act as an abrasive, eventually wearing through the metal threshold plate or the seal itself.
Installation & Maintenance Addendum
Adhesive Selection: Installation typically requires a high-strength weatherstrip adhesive (such as 3M 1300L). Ensure the old adhesive is completely removed from the threshold plate using a non-marring scraper and an approved solvent before applying the new seal.
Curing Time: After installation, it is recommended to leave the cabin door closed and latched for at least 12–24 hours to allow the adhesive to bond and the seal to take its natural "seat" against the door.
Talcum Powder Tip: Applying a very light coating of unscented talcum powder to the bulb of the seal can prevent it from "sticking" to the door frame in hot, humid conditions, preventing the rubber from tearing when the door is opened.
