I agree with Bill, completely. When the F-4 was first returned to flight, the decison was made to leave the seat kits empty. Afterall we were flying in relative safety in the lower 48 and everyone has a cell phone. After flying on the jet from Washigton DC to Birmingham and then on to San Antonio, I realized how wrong we were. After some discussion we decided that we needed to put at least some of the survival basics that the military and the Boy Scouts felt was necessary for basic survival. We now carry a couple of liters of water (which we change out annually ), flashlight, batteries(uninstalled), matches, signal mirror, poncho, parachute cord, multitool, granola bars( again, changed annually ), space blanket,USCG approved signal flares, and a few other goodies. These items were selected for specific reasons, most of which cann be found in the BSA Field Guide, a very useful publications. It is a very well written primer in fieldcraft, so simple a young preteen can understand it ! Just try to get one of those focused on anything for more than 10 minutes !
Anyway, all of these things fit into a seat kit. Both the F-4 and TA-4 are fitted this way. As I told one of the pilots when he asked me what we were doing, " We just got finished puttin a bunch of stuff
you'll never see in the seat kit ". Hope that statement holds true for a very long time.