The Diamond DA40 Star is an Austrian four-seat low-wing cantilever monoplane made from composite materials. It has a fixed tricycle landing gear and a T-tail. Built-in both Austria and Canada, it was developed as a four-seat version of the earlier DA20 by Diamond Aircraft Industries.

The DA40 D uses a turbodiesel engine and burns diesel or jet fuel. It has a constant speed propeller and a single lever engine control,which utilises electornic control units of the engine. Avionics onboard are represented by a Glass Cockpit – Garmin G1000.

The DA40 has accumulated a very low accident record, particularly concerning stall and spin accidents (include no stall-related accidents). The level of safe operation is attributed to its high aspect ratio wing, low wing loading and excellent flight characteristics. The aircraft can be trimmed full nose up, engine set to idle and it will descend at 600–1200 feet per minute at 48 kn (89 km/h) hands-off, a lower rate of descent than the competitor aircraft that utilize emergency ballistic parachute.