7 Pa. Code § 139a.24
(b) A mobile platform used for lifting site personnel or jumpers shall be designed to meet the following criteria and specifications:
(h) A trial lift with the unoccupied mobile platform loaded at least to the anticipated lift weight shall be made from ground level, or another location where individuals will enter the platform, to each location at which the mobile platform is to be hoisted and positioned. This trial lift shall be performed immediately prior to placing individuals on the platform. The operator shall determine that all systems, controls and safety devices are activated and functioning properly; that no interferences exist; and that the configurations necessary to reach the jump locations will allow the operator to remain under the 50% limit of the hoist’s rated capacity. After a trial lift, and just prior to hoisting individuals, the mobile platform shall be hoisted a few inches and inspected to ensure that it is secure and properly balanced. An individual may not be hoisted unless the following conditions are determined to exist: