Two prototypes were built and flown in June 1948, test flights showed a problem with rotor-blade stall at high speed and high resonant vibrations in the whole helicopter.
Dua prototip dibangun dan diterbangkan pada Juni 1948, penerbangan tes menunjukkan masalah dengan rotor -blade kios di kecepatan tinggi dan getaran resonansi tinggi di seluruh helikopter.