A modular floor system with an integral utility for temporary installation in an unfinished aircraft fuselage to facilitate construction. The system includes multiple floor modules, each including a catch pan defining a pan volume, a grid top surface supported on the catch pan over the pan volume, and a utility manifold carrying a utility across the module and to the next module. The modules may be sized and shaped to conform to different installation locations within the vehicle body. The grid top surface is openable to access the pan volume to remove debris or items. Adjacent modules are coupled together with connectors. The utility may be vacuum, air, electricity, or water, and one manifold may carry air and another manifold may carry vacuum. A fixture may be connected to the vacuum manifold and receive an end of a drill so as to remove debris resulting from operation of the drill.