In order to study the effect of cargo movement on the helicopter attitude angle during helicopter heave cargo airdrop

the helicopter CH-53D dynamic model was established. And the rationality of the helicopter dynamics model was validated by comparison of the simulation results of the model with the flight experiment data of the helicopter. Then based on the helicopter dynamic model

the dynamic model of the helicopter heavy cargo airdrop process was established by the separation method

and the trim simulation of the helicopter in these two airdrop states of hovering and forward flight was carried out. The results show that compared with the hovering airdrop

the forward flight airdrop has a better attitude maintaining ability. This is mainly reflected in the fact that the airdrop only affects the helicopters longitudinal attitude angle in the forward flight

but has a great influence on both longitudinal attitude angle and lateral attitude angles in the hovering state.