APB, airline pickling business; prepping for storage until passenger traffic rises to bring them out again. Replace or charge batteries, change oil and filters, check tire pressures and flat spots, grease fittings, dust off the gauges, upload new updates, etc before firing then up. Oh and hang a few pine scented cards or spray Febreze. If no one drinks disinfectant, cleaning the food service area. Then begin the very long preflight.