Berger BX-50 - Single-seat light helicopter powered by a 67kW Continental C90 flat-four engine. First flight trial March 16th, 1961. Badly damaged mid-60's in an accident.
Berger BX-110 - Two-seat light helicopter powered by a 134kW Wankel rotary piston engine. First flight 3 June, 1974.
Berger BX-111 - Project for a two-seat coaxial-rotor helicopter powered by a Wankel-type engine. Not sure if it was ever built.