A dynamic model of a helicopter-flexible rope-slung load system based on Kane's method was completed. Through kinematical description of the system

the system was divided into three parts

i.e.

helicopter ontology

slung rope and slung load.The helicopter ontology is a six-degree-of-freedom rigid body. The slung rope was simulated by a spring-connected lumped mass model; the slung load was simulated by a three-degree-of-freedom mass.Kane's dynamical equations of the helicopter-flexible rope-slung load system were established in the consideration of gravitational forces

aerodynamic forces and elastic forces.For the helicopter ontology and the helicopter-flexible rope-slung load system in consideration of flexible rope

the trim states at different forward velocities were computed first

then the motion modes were analyzed and compared.Simulation results show:the helicopter needs extra collective pitch with introduction of slung load; convergent/divergence rate of helicopter phugoid motion slows down in consideration of flexible rope; Kane's method is suited for building up the dynamic model of helicopter-flexible rope-slung load system

the equations are simple

shipshape and suited for programmable calculation.