[2][3] The main differences were the little retractable landing gear, newly designed canopy cabin, and additional fuel tanks at the wingtips.
[1] The prototype was ready in April 1965, and flight testing began shortly thereafter.
It proved to be very interesting, but problems included the limited passenger capacity and the complicated forward-proof contraction mechanism.
The prototype was abandoned, and sent to São José dos Campos, and stored at Department of Aerospace Science and Technology for a few months.
Later the same year, it was modified by Brazilian Air Force engineers, and new tests were performed, in which it was successful.