Helicopter flight maneuvers often generate high misalignment between the engine and the transmission, which must be accommodated by the connecting driveshaft. Such driveshafts, which spin at speeds over 6000RPM, ofter incorporate grease lubrication and seals. Designs of this type are susceptible to loss of lubrication, which results in overheating and possible failure, a major safety concern.

The Kaflex driveshaft is a mechanical drive coupling which requires no lubrication or seals, and tranmits power while accommodating high anqular misalignment and length change through the use of flexible rectangular frames. These frames are bolted together at the corners in a truss-like arrangement, whick is attached through end hubs from the driver to the driven in the power train. A fail-safe feature enables the coupling to continue to transmit power even in the unlikely event of a failure in a load carrying member.