The DA-40 (GA) engine uses which cylinder arrangement?

• A. Longitudinal Inline
• B. Radial
• C. V-Type
• D. Horizontally Opposed

Answer: (D)

For the DA-40, the engine uses a horizontally opposed cylinder layout, often called a flat four. The four cylinders are in two banks that sit on opposite sides of the crankshaft. This arrangement keeps the engine compact in length, which helps with prop clearance and aerodynamics, and it smooths operation because the opposing pistons cancel out the primary vibrations. Cooling is efficient too since air can flow easily over both sides of the engine. In contrast, inline engines sit along the crankshaft fore-to-aft, radial engines have cylinders arranged around the crank in a circular pattern, and V-type engines have two banks at an angle; these configurations aren’t used for the DA-40’s powerplant.