A system for determining air propagation rate through a pneumatically-controlled braking arrangement of a train, the braking arrangement having a controller for adjusting air pressure of air transmitted through a brake pipe from a lead locomotive to a rear railcar, the system including: a lead device positioned on the lead locomotive and configured to associate first time data with first air pressure data sensed in the brake pipe at a first position; a rear device positioned on the rear railcar and configured to associate second time data with second air pressure data sensed in the brake pipe at a second position; and a control device configured to determine air propagation data based at least partially upon at least one of the following: first time data, first air pressure data, the first position, second time data, second air pressure data, the second position, or any combination thereof.