What condition must be met for the heater to operate in the Beechcraft Travel Air BE-95?

For the heater in the Beechcraft Travel Air BE-95 to operate properly, the cabin vent must be on and the cabin air control must be in the "on" position. This allows for the necessary airflow through the heating system, ensuring that heated air can circulate effectively throughout the cabin.

When the cabin vent is on, it facilitates the inflow of outside air into the system, which is essential for the heater to draw in air to warm. Simultaneously, having the cabin air control in the "on" position allows the heater to function by controlling the temperature and directing the warm air into the cabin area.

If either of these conditions is not met, the heater would be unable to work properly, leading to inadequate heating or no heating at all. This understanding is crucial for pilots and operators to maintain a comfortable and safe environment in the aircraft.