|Manufacturer||DLR and Pipistrel|
|Developed from||Pipistrel Taurus G4|
HY4 is a four seat hydrogen fuel cell powered aircraft. It made its maiden flight on 29 September 2016 from Stuttgart Airport. It was designed by DLR Institute of Engineering Thermodynamics of the German Aerospace Center, based on the Taurus G4, manufactured by Pipistrel.
- "Zero-emission air transport – first flight of four-seat passenger aircraft HY4". HY4. Retrieved 29 April 2020.
- "HY4 Aircraft".
- "HY4: Maiden Flight of the Hydrogen Powered Airplane". www.AviationPros.com.
- Morlin-Yron, Sophie (19 October 2016). "The plane that emits only water". CNN Travel.
- "The HY4 — a plane that runs on fuel cells and emits only water". www.digitaljournal.com. 26 October 2016.