The heating system mixes fresh ambient air with hot air from which system?

• A. Transmission oil cooler
• B. Engine oil cooler
• C. Oil to fuel heater
• D. Engine Compressor

Answer: (D)

The heating system in the TH-73A helicopter is designed to enhance cabin comfort by mixing fresh ambient air with hot air. This hot air is sourced from the engine compressor system. The engine compressor generates hot air as a byproduct of its operation, which is then utilized in the heating system to warm the incoming fresh air.

Using hot air from the engine compressor is efficient since it leverages the heat generated during the engine's operation without requiring additional energy specifically for heating purposes. This integration of systems is essential for overall performance and comfort, allowing for effective temperature control within the helicopter’s cabin environment.

On the other hand, while the transmission oil cooler and engine oil cooler involve systems that manage temperatures and fluids, they do not primarily focus on providing warm air for cabin heating. The oil to fuel heater serves a different function related to fuel temperature control rather than directly heating cabin air.