Saab 21R – Caminar

El Saab 21R was a Swedish twin-boom fighter/attack aircraft developed and produced by Saab. It was a jet-powered development of the earlier piston-engined 21. It was the first jet aircraft to be produced by Saab. Along with the Russian Yakovlev Yak-15, the 21R was one of only two jet fighters to have been successfully converted from a piston-powered aircraft

Fuente: Saab 21R en la Wikipedia