The Ohka 11 was required to be launched within 37 km (23 mi) of the target, making them very vulnerable to defending fighters. The Model 22 was designed to overcome the short standoff distance problem by using a thermojet engine, the Tsu-11. This engine was successfully tested and 50 Ohka 22s were built but never used operationally. This is the only surviving example (marked '59' aft of the blossom) and is on display at the NASM Udvar-Hazy Center.