The ASRO 3T was used to develop the ultra-light side-by-side two-seater ASRO 4. Of welded steel tube construction covered with light-alloy, it had a fully enclosed fuselage pod and tapered tubular tailboom. It was fitted with an 130 shp BMW 6012 turboshaft mounted behind the rotor gearbox driving three-blade main and two-bladed tail rotors of composite construction. This machine flew in May 1964, and was tested for some while before being abandoned without achieving certification.
Rotor diameter: 22 ft 8 in (6.91 m)
Length: 18 ft 10 in (5.74 m)
Height: 7 ft 11 in (2.41 m)
Rotor disk area: 403.45 sq.ft (37.48 sq.m)
Empty weight: 840 lb (_ kg)
Max takeoff weight: 1,360 lb (_ kg)
Max speed: 99 mph (159 kmh)
Cruise speed: 90 mph (144 kmh)
Climb: 985 ft (300 m)/min
Service ceiling: 12,467 ft (3,800 m)
Endurance: 1 hr 20 min."