The first example was completed in 1992 and began testing on January 5, 1993. After the standard tests were completed the HB-4 was flown by local pilots. They appreciated its performance and several Argentine Clubs became interested, though by the spring of 1993 the IGC had declared the shorter span PW-5 Smyk winner of the World Class contest. The second example flew for the first time on 23 September 1994. However, the first prototype crashed fatally on 27 November 1994, leading to the loss of the type's airworthiness certificate.
