As the German attack intensified, particularly on the airfields of Fighter Command, the business of repairing damage, so that the airfields could remain operational, gave rise to problems. As a result of some attacks, the area of the airfield, used as the runway, was often pitted with literally dozens of craters. They were for the time being unusable. Churchill seeing such an airfield, after a raid, decided that what was needed were several hundred strong groups armed with proper equipment and able to be deployed immediately after a raid. These groups did sterling service and were responsible for many an airfield being made usable again in a matter of hours or certainly by the next morning enabling the airfield once more to be operational.