When I was at Patuxent, I did some cat testing to clear the new XYZ box (whatever it was, I can't remember) in the Rhino. The test "graduation criteria" was to validate that the box was structurally capable of taking 150% of the longitudinal load (nose-to-tail G-force) that it would encounter during catapult shots in the fleet , without damage or malfunction. We used the TC-7 catapults that are buried into the asphalt near Runway 32 at Patuxent. They're the same steam cats that are used on the Nimitz class, but mounted on the ground instead of on to the ship. The first shot was a standard 3-G shot, for warmup. Get airborne, then fly once around the pattern, then land. Then the cat crew re-calculated the steam required to give us 3.5 longitudinal Gs. Back into the shuttle for the next shot. Basically, the catapult side (no traps) of a day bagex, just ashore instead of afloat. Then, once more around the pattern, with an extra lap at altitude to cool the brakes. Next shot: more steam, 4.0 Gs. Next shot, even more, 4.5 Gs. On that one, both my pilot and I -- spontaneously and without pre-coordination -- screamed "YEEEE-HAH" over hot mike. The guys in the control room immediately came back with, "Ohmygod ohmygod, are you guys OK?" Our response: "That... was... AWESOME!" Then, 5.0 G's... and the cat stroke was starting to hurt. Then the final shot, 5.5 G's., eyeballs-aft. For about as second and a half going down the stroke, it felt like my heart and lungs were migrating toward my spine. Fortunately, they didn't, because as soon as a the holdback released, everything went back to normal. But I still remember that feeling. We were covered in bruises the next day, at the contact points of our torso harnesses... and it was STILL awesome. Nothing beats Vitamin G.