The modifications made to the Lancair LIVPT are particularly noteworthy, especially in the realm of air conditioning and pressurization systems. This unique system underwent a year-long evolution during the construction process. Unlike the standard setup that directs engine-heated air into the cabin through an air-to-air intercooler and firewall, the approach in N900WB diverges significantly.
In this aircraft, the system prioritizes conditioning the air before it enters the cabin. Initially, hot bleed air passes through a regulating shut-off valve, controlling the amount “bled” from the engine. The air then travels to the aft section, entering a flow pack commonly found in a Beech Kingair. Outside air is drawn in through a NACA scoop in the vertical fin. The flow pack enhances volume and reduces pressure. Subsequently, the air splits, with one path going through an air-to-air intercooler, and the other bypassing it. The air is then directed to the standard Lancair mix valve, now situated on a custom-built plenum housing the air conditioning evaporator. The mix valve is managed by an RC Allen trim servo. The conditioned air is channeled into the cabin through a 4" duct equipped with an inline turbo fan.
Efficiency is further improved by integrating a recirculation system. The aft pressure bulk was modified to create a duct channeling air back to the plenum with the evaporator, featuring an inline turbo fan to ensure positive airflow. A flapper valve prevents reverse airflow.
For enhanced floor heating, an electric heater was installed in the power pedestal. Notably, all composite parts for the system are custom-made using Styrofoam hand-formed molds and wet carbon layups. This system has proven highly effective, maintaining a comfortable environment at all operating altitudes. Beyond efficient functionality, it has significantly reduced cabin noise compared to the original design. The slowed air and increased volume during pressurization contribute to a quieter cabin experience, making this modified aircraft a tranquil and comfortable ride across various altitudes and speeds.
