As it turned out, alas, the test pilot couldn't get to the 70o climb angle until later in the climb, and was always falling short of the world record altitude. He would barely get to 100,000 feet MSL, because of all the energy lost trying to compensate for the lack of precision flying necessary for this flight. But that's not what worried Smith.
What worried Smith was what would happen once the test pilot eventually got to 120,000 feet MSL. He was sure that the test pilot would be out of his realm, lose control of his spacecraft, and, as he entered into the lower and denser atmosphere, would not be able to regain control. But this test pilot was highly skilled in aeronautics, even if his formal education in that area was a bit spotty.
After lunch, Smith goes to the flight line to fly chase for the fourth attempt at the world record. But his airplane malfunctions, and so he goes to the radio shack instead, where he can hear the progress of the flight.
As the test pilot is calling out that he is caught in a flat spin, Smith and another pilot rush to a helicopter and lift off to the crash site. Another chase airplane has spotted the parachute canopy, and is directing the helicopter towards it. They spot the still-smoldering airplane, with the test pilot calmly standing next to it, just waiting. He is badly injured, but he will survive. Flown to the base hospital by helicopter, the pilot is treated for his injuries. In time, he makes a full recovery.
But Smith was right all along. Well, at least partially right. He thought that the test pilot would fail in the space environment, and not during the aero environment. It turns out that the test pilot couldn't even fly the proper aero profile, and thus got himself into trouble, because his RCS would not work at the lower, denser altitude.
But what was even more amazing was the fact that the test pilot who screwed the pooch turned out to be, as it were, un-screwable!
The test pilot was world famous for his exploits in the air. He was what is called a "natural-born stick-and-rudder" man, which refers to airplane controls. He had set various other world records, and had basked in the glory and fame that came with them. He was indeed America's poster boy of all test pilots, then until now!
However, that was yesterday, and sometimes the American audience can be so... fickle.
Now here was his chance, or so he thought, to reclaim some of those glory days. The AST presented itself with a golden opportunity. Despite his skill in the cockpit, he had been passed up by NASA for not only the X-15 program, but for the new Mercury program as well. Why, he had been part of the X-plane program virtually from the start! While the AST wouldn't be going into actual space, it was going into an environment that was close enough. He would be able to know what it was like to be an astronaut, AND get to set another world record. Likely he had this notion in mind: "That'll show those astronaut boys." I mean, how hard could it be?
Smith keeps up the briefing before every world-record attempt. However, this Smith fellow, who means well, just doesn't understand. The test pilot had been in this business for a while now, and he didn't need any coaching from these newcomers with their fancy aeronautical engineering degrees.
Except... it turns out that it was indeed just a wee bit harder than he had first imagined.
The fly in the proverbial ointment comes down to the finer point that there is just so much to do on the way up to the top of the arc! The 3.5 g pull-up was no problem, but maintaining that 70o climb angle, while monitoring the Navy instrument that tied a pitot tube to the glide slope and glide path indicators, was a bit sticky. He would eventually get to the proper angle, but not right away. During the climb, his engine would begin to overheat due to the ever-thinning air. Consequently, that part of the flight not only had to be monitored, but eventually the jet engine had to be shut down while the rocket was still firing. The rocket eventually is shut down, with the test pilot intersecting and maintaining a 16o angle-of-attack, and using the RCS to push the nose down, enters the thicker lower altitude, restarts his jet engine, and lands back at Edwards.