What It Looks Like

One reason manufacturers are able to build a two- or four-place single-engine, piston-powered airplane that weighs far less than your average car is because a piston single is a simple design, with a simple structure and simple systems. Most of the systems operate with few parts, so they are light in weight. A good example of a simple, lightweight system on a piston single is cabin heat.

When you turn on the heat in your car using a rotary knob, push-button, or lever, you're probably opening a vent door or two and activating an electrical current that turns on an electric fan that blows air heated by the engine coolant which is circulated by the engine-driven water pump, etc., etc., etc. It's a complicated system involving lots of heavy parts, hoses, electrical controls, and pumps.

When you turn on the cabin heat in a Cessna 172 or Piper Warrior or just about any other basic piston single, all you're doing is moving a cable connected to a vent door. No fans, no electric controls, and very few moving parts.

The system begins with ram air collected from a scoop on the nose or from a port in the baffling surrounding the engine. (The baffling creates a sealed area around the engine to direct ram air across the cooling fins on the cylinders. It's another example of a simple, highly efficient system.) The ram air then travels through a flexible hose into a shroud that encloses the exhaust muffler.