The Heinkel He 72 Kadett (Cadet) was a German single-engine biplane trainer of the 1930s. It was known to its pilots as the Zitterrochen (Quivering Ray) as it shook madly.
The Kadett was designed in 1933 to meet an official requirement for a basic trainer. It was a single-bay biplane of fabric-covered, metal construction with open cockpits, a staggered wing, a strut-braced tail unit, and fixed tailskid undercarriage. The prototype was powered by a 104 kW (139 hp) Argus As 8B air-cooled inline engine.
The first production model, the He 72A retained the As 8B engine in early batches, but later production aircraft had a 112 kW (150 hp) As 8R. The He 72A was superseded by the He 72B, which was the major production version. This was powered by a 120 kW (160 bhp) Siemens-Halske Sh 14A radial.
The He 72B was produced as the He 72B-1 landplane and He 72BW Seekadett ("Sea Cadet") twin-float seaplane. The civil development was the He 72B-3 Edelkadett ("Noble Cadet").
The Kadett entered service with National Socialist Flyers Corps before the formation of the Luftwaffe. Later, it became a standard basic trainer with the Luftwaffe. Slovak forces used it in the attack role.