Beatty-Johl BJ-4
The BJ-3A appeared in 1968 and this was followed by the BJ-4, two of which were built for the 1970 World Championships, in which the existing BJ-3 wings were married to a new fuselage and tail unit, the T-tail being replaced with a taller fin and rudder and an all-flying tailplane repositioned on the fuselage behind the rudder.