With the tremendous acceleration, I had difficulty in positioning my head in order to see around the left hand console. At the 40 second pushover, I had to feel for the dive brake handle but had no trouble in actuation. Because of the very slow period in extending the dive brakes, there didn't seem to be much, if any change in acceleration.

Engine burnout occurred just past 80 seconds and at the time I felt this to be somewhat premature. The yaw and roll damper were turned off with ASAS coming on the line, and a right rudder input and release recorded at a = 3°. Mach number had peaked out at 5.4 and had bled down to about 5.3 by the time the maneuver was initiated. The rudder input set up a yawing oscillation of about 2° amplitude which appeared to have a period of around two seconds. Although it didn't appear to be divergent, it was neutrally stable and created some rolling oscillation of about the same period and maximum bank angle of about 15°. Angle of attack was increased to about 12° then to about 15° with the airplane still oscillating in yaw and roll. There was no real need to disturb the aircraft inasmuch as it was already oscillating quite heavily in yaw and roll. Looking at telemetry data a few minutes ago, the amplitude resulting from the yawing oscillation at this time appears to go slightly divergent.

I attempted to utilize ASAS to steady out the oscillations, but found it to still be in the armed position. The ASAS was then turned off and rudder kicks again recorded up to about 18° a at a Mach number of 4.9. The aircraft really did not have to be disturbed, and there is some question as to the actual rudder kicks accomplished and those only attempted. ASAS was used occasionally to stable the oscillations; however, this appeared to amplitudes, especially in yaw, and at one time yaw was fed out to 6-8° b when ASAS was engaged. Inertial altitude read about 129,000 feet.

The roll appeared to be much less than that experienced on the simulator, with the yaw and pitch modes causing the most concern. If anything, the airplane appeared to fly better without ASAS on, but still very poorly in both yaw and pitch. During this time no real attempt was made to actually control either yaw or roll, and consequently I did not experience or notice any adverse yawing effect with aileron input.

At 4800 ft/sec which appeared to be somewhat early, I got the call for speed brakes in. I did not notice any significant change in controllability except in pitch, for with the brakes in, angle of attack was somewhat more difficult to control. With brakes either out or in, any precise control in pitch, or let's consider pitch damping, was about half as compared to what the simulator was showing. If corrective action was taken, the aircraft would oscillate from 15 to 18° a down to zero and then back again.

At this time, I received a call from NASA 1 to come out with the speed brakes and lose energy. I could see the field almost under the nose of the aircraft. The next series of maneuvers was mostly directed toward positioning to high key, although a few rudder pulses were obtained with ASAS off during this time.

A RAS check was recorded at about 1.6M from a series of control motions about all three axes. A left turn was made to high key with quite an excess of energy, to the extent that the overhead and downwind were made at low supersonic speeds. While heading for high key, I noticed an onset of light to moderate buffet that appeared to persist without any change in magnitude or frequency regardless of any change in altitude, angle of attack, indicated airspeed, or Mach number. The buffet was noticed at 48,000 feet and Vi = 280 knots, and to my knowledge persisted at least to the turn on base. Dive brakes were bled in and out at random from approach to high key to the time base leg was initiated with no apparent change in buffet level; however, because of concentration on the approach phase of the landing, I do not remember just when the buffet stopped. The straight away was started about 12,000 feet and 320 knots indicated was held almost to the flare. Before I forget, I should mention that RAS was turned off before high key with also no change in the buffeting.

One thing I would like to again bring up is that ASAS did not seem to help the controllability of the aircraft at the higher Mach numbers. If anything, control became somewhat worse although I will say again that no large aileron inputs were necessary so we really didn't get into any noticeable adverse aileron effects. Also I think we did the right thing of going to a low q region at the higher Mach numbers in taking a first hand look at these problems.

I didn't experience the explosion of the 2nd stage igniter during the powered portion; however, the banging and sledge hammering effect after shutdown seemed to be more than usual. The airplane seemed to decelerate less after burnout than the simulator showed. Also, on getting the call from NASA l for speed brakes out and to vector to high key position, I felt that another 50 miles of flight path could be used. About 3/4 speed brakes were used during the turn to high key, then bled back in and out at random.

Just before drop, Joe, it looked like we had a little radio trouble. Every transmission you made that was unreadable was loud and clear on the second time around. Other than this, we had no radio problems.

In getting back to the landing phase, the runway was so rough at touchdown that the nose gear became trapped in one of the grooves and appeared to make like a sine wave down the runway. I would prefer to land either side of the marked runway or better yet, have 18 remarked to one side. It is almost as bad as 23.

Although from this particular flight it appears that this airplane can go to these higher angles of attack without the ventral and with dampers off, we should proceed with caution and analyze each flight well before proceeding to the next. I think that a reentry with this configuration would be more of a control problem than just pulling up and disturbing the aircraft in yaw from a stable condition.

Someone asked me about chamber pressure. With roll SAS going off at launch and the unsuccessful attempts at reengaging to get back on profile, I did not notice what pressures I had at 100%. I had thrust and it was really a pretty good kick.