A falling-object protective structures (FOPS) test assembly for carrying a FOPS test of a wall of cab of a heavy vehicle is configured to releasably carry a test ball for the FOPS test above a predefined distance above wall. The FOPS test assembly defines a closed path for test ball from its housing position to wall, and includes a handling means configured to assume a first condition in which they do not interfere with the passage of test ball through the closed path when ball passes through closed path in a first direction and a second condition in which handling means lock and hold test ball within the closed path once test ball passes again through the closed path in a second direction opposite to the first direction.