The media said that the United States received technology from Russia to develop a Compound Coaxial Helicopter (CCH) attack helicopter
As writes “Tape.ru ”, referring to The Aviationist, the United States was transferred to Soviet technology. Executive Director of the American enterprise-developer of the helicopter AVX said that the Russians were surprisingly open in their technology. They flew in coaxial helicopters for many years.
According to the director, Russian specialists presented technical documents at various meetings. They developed a spacing criterion between the screws, which turned out to be working.
It is noted that the engineering solutions that the Russians used in the design of the Ka-50 and Ka-52 helicopters allowed the Americans to improve the characteristics of their device.