Flight: 3-44-67
Date: June 29, 1965
Pilot: Capt. Joe Engle
I. PRELAUNCH AND LAUNCH PHASE
2. X-15 radios - Were normal.
3. APUs - APU operation was normal.
4. Damper system - Worked.
5. Flow direction sensor - Was normal.
6. Launch space positioning - Was good.
7. Launch transients (q, f, y) - I think I got a little bit more roll off to the right than what I anticipated. I overshot a. In the cockpit film it looked like about 13 degrees or so, then back to 11 degrees.
1. Engine operation - Was normal.
2. q control - Was real easy.
3. a control - Was no problem at all.
4. Altitude profile versus simulator - Was just about like what we'd seen on the simulator. I think we peaked out about 2,000 or 3,000 feet higher on the simulator than what we did with the airplane, but it's pretty hard to get any closer than that.
5. Unforeseen incidents - There was a thrust misalignment there. The airplane started off to the left. I wouldn't have known without looking at the record, but it looks like about 7 seconds before burnout I put a correction in. At any rate, I made a correction, not a big or a violent correction, but I eased in a little bit with the rudder pedal. I saw the needle start back towards the middle and then I started paying attention to the shut down conditions for velocity and altitude and didn't notice it again. It looks like I took my foot off the rudder and allowed it to drift on out to about 4 degrees sideslip at burnout. It wasn't noticeable as far as feeling was concerned.
2. Stability in ballistic flight (RAS ON) -
q 1 , f 2 , y 3 .
For pitch, it was very good. Of course, we had pitch hold mode on and I was controlling pitch angle with the vernier trim. I'd rate that 1. We never got away from the desired pitch position, and, therefore, there weren't any large inputs required. So there wasn't any problem in pitch. Roll was the same way. It was very easy to control. I'd say about a 2 on the roll because we had the roll task on the way up from 260,000 feet on up to the peak. In sideslip, I guess about a 3. After going to delta psi and working the roll maneuver, the vertical needle drifted over to the left, almost to the peg. I brought it back with a control input. There wasn't any particular difficulty bringing it back or stopping it, but in yaw it did seem to drift more than in the other two axes and you had to pay attention to it more during the start down hill to get set up for the reentry, make sure it was nulled out.
2a. Controllability in ballistic flight (RAS ON) -
q 1 , f 2 , y 2 .
I would say pitch is 1 and roll is 2 and yaw is 2. "Do you feel that the airplane was stable in yaw?" It felt like it was about neutrally stable in yaw. If anything, probably a little bit divergent, but at a real long period oscillation so that it was no problem controlling it.
3. Controllability during initial and terminal reentry -
Initial q 2 , f 2 , y 2 .
Terminal q 2 , f 1 , y 1 .
For the initial part, the pitch control task I'd rate about 2, roll 2 and yaw 2. Terminal phase, pitch 2, roll 1 and yaw 1.
4. Glide energy management versus simulation - Seemed to work out pretty much like on the simulator although it seemed like we got rid of the energy just a little bit faster than we had been on the simulator.
5. Approach and landing - Were normal.
6. Unforeseen incidents - No unforeseen incidents there.
q 2 1/2 , f 1 , y 1 .
Bringing alpha up slow and steady for reentry was probably the most adverse task. And for that I'd rate 2 1/2 on pitch, roll 1, and yaw 1. No problem on either of those. "Did you have to damp out the yaw oscillation?" No. This was a very slight oscillation in yaw, just prior to the pitch oscillation. "Like the simulator?" No. Not like you see on the simulator, like you see in the airplane and you never see it on the simulator. Just as you start to come down in, I don't know whether it's because the airplane is not quite lined up, it should be because you're getting good q ball and the vertical needle is centered, or whether it has a little bit of roll in or just what it is, but you seem to get just a little bit of a hunt. You never see it on the simulator. "It's the weather vane effect." Yes, that's what it feels like exactly, and it's just at the onset of q. It seems like it gets stabilized out and weather vaned out and that's all there is to it. Then this little 2 or 3-degree pitch oscillation followed that for about 2 or 3 cycles. "Did you try to damp that oscillation?" I think the first oscillation I tried to stop, and then I tried not to feed it any more just to see what would happen because it was so small. When it started, my first impression was to get it stopped and then I figured, no, I'll just hold it steady and see what happens to it and by then it was just about died out again. "Could we have a few words on this sense of feel for setting up for reentry?" Well, I was paying a lot more attention to the stabilizer positions on this flight than on the last one. Coming over the top I had decided to go ahead and set the stabilizer, or to get the stabilizers in at least a fairly good airplane nose-up position and give the "horse its head" and see where the airplane would go, at least in the initial part of the reentry. The nose dropped down to, I would say -15 degrees pitch angle. I think that's about the steepest I saw on the ball. I initially was going to try to hold the nose up, but it just didn't feel like that was the right thing to do. It would be more of a mechanical than a natural thing to do with the airplane. You could just about feel when you were doing something that you shouldn't do with the airplane, like trying to go up too fast on alpha or go up too high on alpha. It just seemed natural to let the nose drop down and then pick up alpha as soon as you could. Unlike the simulator, it seems like you can feel about how fast you should come up on alpha and how quick you should get it. "Were you, by any chance, flying by the change in stabilizer, were you sort of flying on the stabilizer gages?" No, I don't think so. I'd look down at them occasionally, but I wasn't watching them continually. "Did you use the dial trim?" Right, I think I had about 1 or perhaps 1 1/2° nose up pitch rate cranked into the dial trim. I'd been flying the simulator with about 2 degrees on the reentry and it seemed to work out real good. I suppose I could have held it a little higher on the airplane. "Did you by any chance, look out on the initial part of the entry to see where the base was?" Yes, but I couldn't really tell directly. I got the impression that we were going to have to really put the binders on to get stopped. It looked like it was right down between my legs. I didn't get the feeling that I was over rotating on the climbout. I got the feeling that I might have held the g in too long and that it over rotated during the reentry maneuver and was going to start back up hill, so I was keeping one eyeball on the rate of climb indicator.
When I was sure that the platform was working, I shut
down on velocity and pushed over to zero g. I looked up at the clock and
it had overrun to 86 or 87 seconds, so I'm not sure exactly how much burn
time we did have. But I didn't watch the predictor at all on the way up.
From the cockpit film it showed 272, or 273,000 feet at burnout. It drifted
up to about 285,000 as we went through 260,000 and then as we started to
peak out it decided it ought to read the same thing as the altimeter so
it came back down to 280,000 and stayed there then.