During flight operations in the Beechcraft Travel Air BE-95, what pressure is utilized for the cabin heater?

The cabin heater in the Beechcraft Travel Air BE-95 utilizes ram air pressure. This is because ram air pressure is created when the aircraft moves forward through the air, causing air to be directed into the aircraft's system. The system takes advantage of this dynamic pressure to operate efficiently and provide heat to the cabin.

By using ram air, the cabin heater can draw in the ambient air, which is then heated and circulated within the cabin. This method of heating is effective during flight when the aircraft is in motion, as it ensures a continuous supply of fresh air that can be adequately warmed.

In contrast, vacuum pressure is primarily used for systems that require a low-pressure environment, such as certain gyroscopic instruments. Positive pressure might refer to systems where air is pushed into an area, but for the specific function of the cabin heater, it's not applicable. Static air pressure does not involve airflow dynamics and wouldn't provide the necessary air movement for effective heating. The reliance on ram air pressure is a key feature of the heating system's operation and efficiency in the BE-95.