The invention belongs to the field of aircraft drop
simulation and test, and particularly relates to an aircraft sinking speed determination method and
system under the condition of no lift force and no
mass reduction, and the method comprises the steps: determining parameters needed by the dynamics
simulation of an
aircraft landing gear according to a test working condition; determining the mechanical relationship of the undercarriage according to the parameters required by
simulation, and building a full-
aircraft landing simulation model; performing lift simulation on the full-
aircraft landing simulation model, and determining a vertical ground load of the aircraft
landing gear; extracting a vertical ground load of an aircraft
landing gear, performing lift-free drop simulation on the full-aircraft landing simulation model, and iteratively determining a putting height according to the ground load; and calculating the sinking speed of the full-aircraft
drop test according to the putting height. Compared with the prior art, the method has the advantages that lift force simulating loading equipment is omitted, initial launching attitudes such as the
pitch angle, the roll angle and the
yaw angle of the aircraft are fully considered, the method can be used for guiding initial launching of a
drop test, the large overload risk of
free falling impact is reduced, and the number of times of adjusting the launching height can be reduced.