Starting/Running equipment: Propane, unless you're kero start, some way of getting the propane in the turbine, Smoke fluid and pump, Kero and pump with turbine oil, TWO chargers, ONE BIG BAD 12 V battery, your transmitter, wings

Fire suppression: ABC and C02, Water (I'm the ONLY one I know who has one and brings it to the field...I have it in a g 5 gal ardening insecticide sprayer paid ~$40ish at Home Depot)

CA accelerator, if you're going to any overnight meets: Hysol

TOOLS: Hex drivers, hex wrenches, phillips, flathead, needle nose pliers, regular pliers, hemostats (long and short), wrenches, glow plug remover, ruler/ caliper, voltmeter, GSU, soldering tool, tap and die set (4-40 and 6-32), some sort of jet carrier that can support it upside down, this list could go on ad infinium

Spare Parts: Extra wheels, common bolts used on the F-18F (that weird 5-50 size), common nuts and bolts (4-40, 6-32) spare turbine support equipment (3, 4 and 6mm Festo connectors, stop cocks, etc), like Ehab said, flex plates (only nose gear has flex plates in Tam's F-18f), spare servos, servo Y-harness, extensions, servo connectors, Tamiya connectors (esp if you have a jersey modeler), multiplex connectors, etc...

Comfort: Wing Bags, Hat, sunglasses, chair, sunscreen, water, leaf blower, Cart to schlep all this stuff around

I'm sure I forgot plenty....

Raf