A longitudinal stability monitoring system controls a boom lift down speed for a lift vehicle. The lift vehicle includes a vehicle chassis supported on front and rear wheels respectively coupled with a front axle and a rear axle, and a boom pivotally coupled to the lift vehicle. The system monitors a vertical load on the rear axle and manages boom lift down speed based on the vertical load. Additionally, the system may manage the boom lift down speed based on both the vertical load on the rear axle and an anticipated operator demand according to a signal from an operator input device.