Abstract
The present study investigates the aerodynamic jump phenomenon effects on flat-fire no-wind unguided flight trajectory disturbances for projectiles designed to be launched at supersonic speeds in forward fire from air vehicles. The ammunition used is the 30 mm diameter XM788 projectile firing from M230 machine automatic cannon. The modified linear flight simulation model is applied for the free-flight atmospheric motion prediction of the examined projectile including the variable behavior of the most significant aerodynamic forces and moments coefficients, which have been taken from official tabulated database.