PILOTS COMMENTS

Flight 3-5-9 X-15-3

Pilot: Major White

On pre-launch activities the only apparent difficulty we had was with the intercom system. Of course, you know we had this on the ground and then it apparently got better. At some stage in the flight it got real bad. I could tell someone was talking but it was unintelligible so I switched over to the radio and tried it a few times. We stayed on the radio and the quality was good throughout. Other than that, everything on pre-launch seemed to go very well.

At launch, we had a good light up to 100%. I held about 7°, oscillated about 7° angle of attack. I guess we got our 1000 q. During the rotation, I got a fairly high frequency oscillation in roll. It was low amplitude. It wasn't very disturbing but it was there and I could sense it. By the time I got up to 20° pitch angle it died out and was real solid from there on. I went up to my pitch angle, I was about 2-1/2 seconds behind getting, there. When you called 40 seconds I was still just shy of getting there.

This flight control system was just marvelous at this point. We went ahead and started going up to profile. It gave me an indication that I was a little low and then that I was on. The reason that we went low on the profile was because of me. When we got up to 32°, and at about 6O seconds in time, I guess it was just a small case of disorientation. I say a small case because I didn't lose complete orientation but when I was up at this climb angle, and this is the first time that I've had this feeling, I looked at the ball, I had 32° in pitch, but I had the darndest feeling that I was continuing to rotate. I couldn't resist the urge just to push on back down until the light blue of the sky showed up, I never did get to the horizon, then I was satisfied that it wasn't happening. I pulled back up but that's the reason for the lower altitude.

I got to 77 seconds about a second and a half sooner than you called me. You were slow on the time. Realizing that I was low on the profile, I delayed it just a bit, did a slow retard and shut it off. I would guess that I had at least 79 or 8O seconds on burning time. Somebody might verify that.

I let the airplane droop but I didn't push to zero a It came down steady at about 11° and it sat there like the rock of Gibraltar so I just let it sit. I slowly came over to level flight at about 10 or 11° angle of attack, staying right there. It was almost uncanny it was so good. When I was just about level I rolled the airplane both left and right, fairly abrupt, I just threw the stick over to the right and then back over to the left. I threw out about 3 or 4° of sideslip with the roll but as soon as the roll stopped this sideslip banged right back to zero. Another interesting thing here, there was none of the banging, cracking and popping that you always get on the other airplanes.

In level flight I increased the angle of attack up to 20° and during this portion of the flight, on at least 3 occasions, I was able to catch exhaust from the BCS. I was able to see it and this was surprising to me. Also, while attempting to hold it up to 20° angle of attack, on at least 2 occasions, I could hear the BCS operate and from the sound I couldn't tell where it was coming from. I suspect that it was trying to keep the nose pitched up. I held the 20° and at the top I indicated, as the rate of climb came to zero, 183,000, 184,000 on the inertial indicator. I didn't catch the velocity at that point. Later on in the flight I called when the velocity was at 4000 ft/sec so that might have been a point at which you could compare with my actual velocity at the time. At 20° angle of attack, the airplane again was just as solid as a rock, it drooped down on the entry to about 17°. I tossed it around just a little bit but it was so solid that I was just almost unconcerned about it. Again at the top I called out the cabin pressure because I could feel my head wedged up in the canopy just a little bit as I tried to turn around and look at the trim indicator, just another look to make sure it was zero, and I sensed that I had an inflation at 37,000 feet on the cabin altimeter.

The reentry progressed and I got up to just a little bit over 3g. I came level and after I called the 4000 ft/sec, Bob, you said hold the speed brakes so I held the speed brakes and went ahead and pulsed the airplane, the adaptive dampers on, then went ahead and went over to fixed gain, kicked it around a little bit. We had decent damping at the conditions which I pulsed the airplane but you could obviously tell the difference at fixed gain from when you have adaptive dampers.

I didn't get a call, or I may have missed it, but a good cue would have been someone to look at my energy and call again the speed brake extension.

Statement: They told me they were out so I didn't have to call you.

Well, they weren't out so I went ahead and after I reengaged the adaptive dampers I flipped on my angle of attack hold and I flipped the airplane over to see what my position was. I had to throw out speed brakes there because I had a lot of energy to kill.

Statement: When I told you to hold the speed brakes, John had already told me that you had partial speed brakes out.

I was on angle of attack hold very briefly. About this time I started worrying about managing the energy for the landing. I switched over to pitch hold and I was on pitch hold while I was deflecting the speed brakes and I got a good deceleration and was satisfied that this was all right. Then I rolled over into a right hand bank, 20° bank angle, went on roll hold and disturbed it from the 20° position and it returned. I crossed over, was over the north lake at 2000 ft/sec so I turned off to the right and then came back around to the left and reengaged roll hold at 40° bank angle on the left turn and this was holding good. Both the angle of attack, the pitch and the roll, I thought, were quite tight. I went ahead and knocked off the hold modes and just continued on around for the landing.

Now in the landing, I went through on sidestick all the way. I didn't try to adjust or change my technique. I came in and made the usual type pattern. However, I was a little bit more cautious I think in upsetting the airplane and figuring on gust disturbances and so forth driving this gain down, so when I got down to about 20 or 30 feet in the air I just held it and let it gradually settle on down. This airplane was just fine as far as I'm concerned. I could have kicked it around even more and glued it down to a better spot than I had. This was no problem. My impression is very favorable. This flight control system is quite remarkably good. I like it and I'd like to try it again. The flap extension didn't give me any problem. I didn't get the trim change with flaps that I normally get. Trying to sense this in the stick, too, I couldn't sense it. With the simulator, of course, you sense the delay in trim follow-up and you're not nearly as aware of this in the airplane. Only during the initial rotation was I aware that perhaps the trim was a little bit behind the force that I was holding. Beyond that there's no problem at all. I had the distinct feeling here, flying with this flight control system working the way it was, that the pilot could divert considerable attention away from his primary task. On all previous flights I felt that you were quite glued to the task at hand in flying the airplane.

The only time that I used the hold modes was in the terminal part of the flight. During the rest of the flight you definitely have the feeling you could start diverting your attention away to other things. It was real good.

There was no peroxide warning light. I don't think that I would have used more than the system was calling for itself because there's not a lot to do, its so easy to fly.