Air Supply and Cabin Heating Systems

Air Supply

• Vent air can be supplied through the heater unit, by ram air, or by fan through the upper vent ducts.
• Air is supplied to the upper vent system through an inlet on the leading edge of the vertical stabilizer or through the inlet located on the left side of the aft fuselage, depending on serial number.

Cabin Heating

• Heated air for the cabin and defroster operation is obtained from the combustion heater located in the nose section of the airplane.
• Fresh air is supplied to the heater from an intake in the nose, routed through the heater and into the cabin through six adjustable outlets.
• Operation of the heater is controlled by a three-position switch located on the lower right side of the instrument panel and labeled FAN, OFF, and HEATER.
• The FAN position operates the ventilation blower of the heater and can be used for cabin ventilation or windshield defogging on the ground when heat is not desired.
• For additional defrost capability, adjust the cabin temperature control and then adjust the three-position switch to HEATER.
• For cabin heat, the air intake lever located on the lower right side of the instrument panel must be partially or fully open and the three-position switch set to HEATER.
• This will start the fuel flow and ignite the burner simultaneously.
• Heat should be felt within a few seconds due to the instant starting and no need for priming.
• There are two safety switches installed at the intake valve, wired to prevent both fan and heater operation unless the air intake valve is moved off the closed position.

Explore the systems used for air supply and cabin heating in aircraft. This quiz covers the mechanisms involved in supplying vent air, the operation of the heater unit, and the implications for cabin comfort and defrosting. Test your knowledge of these crucial features in aviation.