ON MAY 25, 1961
Walker: I can summarize this flight by saying that I have flown better ones. You will find that this was not the best flight that I have ever put out, either from the adherence to the program or the steadiness of the aircraft while it is on its way, but I had problems. I repeat, I think we could do with some viscous damping on that side stick so it doesn't jiggle around just by thinking about it, and further, it is very difficult to locate roll neutral on there, so that our happy troops that are advocating the use of b-dot technique for remaining erect in the event of loss of roll damper, your simulation out there is pretty accurate on what the airplane is like relative to the operation of the handle. Also it will be very difficult off trim. However, we do not get any feedback from the system back into the handle. There is nobody out there kicking the handle back at you.
Naturally, since we started early with the cabin -- with the X-15 supplied LN2, we didn't have a loss of that (prior to launch, that is) and everything was looking real good. Boy, I got my guarantee on the engine today. No waiting. There I was at full thrust just as fast as I could get the handle up there into that stop; and then the pitch damper went out, as was indicated by the flashing amber light; and about that time the roll damper went out as indicated by the flashing light. I decided best I try to turn on the roll damper first, and that reset, but the pitch wouldn't, so there I was; and between the sidearm stick and no pitch damper, we were all over the sky. Practically the whole flight. I averaged 7° a during the portion of the roundout there. What was the q? Oh, our Beatty people aren't back yet. At any rate, I can assure you that the residual oscillation does come on with increase of q, and furthermore, I decided I wasn't going to carry it as far as we had it on our simulation, so I made two reductions in roll gain. I can't remember now whether it was one notch or two in the first operation or the second. I think possibly we may have got a little higher on q than 950, because I had trouble keeping angle of attack up for part of the time, what with trying to keep the nose from jumping around. Side stick is much more difficult for doing a smooth wings-level launch and pullup. There seemed to be no problem with the center stick, but with the side one you really got to get in there and fly. Along came the callout at 35 seconds. We were smarter than we knew when we did that, to warn that we were about to come up on 40 seconds, because I took a quick look at the stop watch, and it said zero. (Right away, there is another one. A fella told me a yarn yesterday, about this that kept having things going on, and he figured the next step would never work. Well, I looked at it the opposite way. I figured everything was going to work, and then was chagrined to find out it kept dropping out on the way.) So about this time, why I thought it must be about 40 seconds, in time to pushover to zero g, so clunk, and the airplane went about 10° nose down just thinking about it, and I had to pull that back up. I imagine that we netted an early pushover due to a faster rate and accounted for some decrease in the peak altitude. However, observed indicated speed up there at the top was about l90 knots, so we got low enough q.
As for the airplane -- I'll summarize the pitch side of this by saying that every time I made a control motion in pitch, it bounced with no damper, until we got well subsonic. I didn't even pay any attention to the fact that we didn't have any pitch damper on landing; however I came out the same as ever down there. The airplane wallows terribly with the gain setting of 6 on the roll damper; and I went through the yaw pulse with 4 on yaw gain, and 6 on roll gain after shutdown, then back up to 8 on the yaw gain; and after steadying out and getting cranked up on angle of attack up at the top, I did some aerodynamic and reaction control pulses. I am unable to sort them out in what order they were done, but both systems got used up there. I am charging along, still doing pulses when the big fat transmission came over "We've lost radar track", and my first concern was out the left window and where is Rogers Lake? I got that firmly in sight, and about this time they got the track back, I guess, and called for a turn which I saw was necessary; so we got that thing turned around and it looked like a long way home to me; so I started setting up, getting down to best L/D and conserving altitude. The airplane sailed along. It didn't shock me any, the rate of descent that we had per mile of longitudinal travel, but apparently the control room was bothered somewhat. I could see by the apparent aim point, from quite a ways out, that we were going to make the lake; although, with a cloud between me and it, after a while there I was debating what I would see when we came out the other side; but I was prepared to either bend around a couple of S-turns for a straight-in, or to carry it in on over the lake, which we were able to do. Also, concurred with NASA l that it was time to get rid of any weight that we could throw overboard, so I hope Rushworth isn't too aggravated that we jettisoned while he was on one side of the cloud and I was on the other. Pattern came out nice, no strain there.
I noticed I was getting pretty warm in the cockpit. Every spare chance I had I was cranking the vent open another half a turn. Still had some left when we got down on the ground. One physiological comment I could make was this. In the pressure of events, we were trying to get damper reset and what not, and I wound up sitting pretty well hunched over there so I could reach down and get hold of that switch, and I was still trying it while I was flying the climb out pattern. Somewhere up there along the line, about the time I pushed over to zero g, I thought, "Boy, it's getting hard to hold up my head," and it dawned on me that I didn't have to. There was a rest back there that I could use if I wanted to, which I did. In the act of dropping my head back, suddenly this airplane felt like it just went right over on its back, and fortunately, the old seat-of-the-pants instrument training came to the forefront and says, "Now, what do those gages say, let's stay on the ball." But it was an immediate reaction to tilting my head back. My sense of g-vector said that the airplane was going over on its back. At this point I took a fast look out and the sky was still up there, not going by either. Outside of that, no noticeable phenomena from that score. I didn't, in fact, notice our cabin had leaked off and the suit had pressurized until, earlier than the controller called out, I attempted to turn off the BCS switches, since I saw that I was up good on q and through with them, and I couldn't reach them with my left arm on account of the left arm was all swelled up and wouldn't reach that far, so I had to change hands and do that. Another thing, the cabin altitudes seemed to be 50,000 feet at that point. It hadn't affected my ability to run the control one iota, and I think, although I haven't mentioned it, that all this moving around in the cockpit and what not may have bothered me some with steadiness laterally. But really there was less of a problem with that side stick, and here I can say a good word for it; it is a lot less of a problem using the side stick with moving around and leaning forward or trying to reach forward and get hold of things, than would have been over the center stick, because I got tired of fussing with a jittery airplane after I got straightened out for home. I tried to move the center stick and discovered that this was too much of a job to; really, the other one wasn't that bad. The stick was clear back in my gut, using a lot of stabilizer, and I had to bend the suit arm again to hold that; so I went back to the side stick and flew that until I got subsonic, when the center stick got a little further forward on trim. I guess maybe I better quit, questions are better than keeping on with this.
Question: Did you notice whether the BCS was effective in each plane?
Walker: I didn't get enough roll, but pitch and yaw, I had plenty there. This correlates with simulator experience on practicing for this. At this kind of q, which I imagine was on the order of 250 or something between 200 to 250, the aerodynamic lateral control overpowers the BCS very easily. There will be a later point where the BCS control effectiveness is worthwhile laterally.
Question: Do you have any comment on inertial system and pilot's display?
Walker: Catch this one, I read 4,950 feet/sec on shutdown. Further, I double checked when he called out altitude 110, 000 feet . I was very close to being on, in altitude, on that one. I generated so much confidence on that system that it shook me up a little bit when it went subsonic still indicating about 1,600 feet/sec, and you get carried away a little bit there, forgetting that it will drift. That is what the whole problem is, so I quick went over to aerodynamic indication. So once I made this transfer, I didn't look back at it any more, until finishing up on the ground out there.
Question: Did you notice any adverse effects at engine shutdown?
Walker: Nope, there were so many ordinary transients going on and I wouldn't have been able to separate any specific one at that point. I didn't have any trouble reaching the throttle, not a bit.
Question: Did you notice any wallowing when you increased a after engine shutdown?
Walker: Yes, this is where that comment about wallowing laterally applies, combination of high a and low q. You have to pay attention to controlling the airplane laterally. There are just no ifs, and, or buts about it.
Question: Did the roll residual oscillations at high damper gains bother you?
Walker: I say, although I don't know what the q was, and suspect that we were on the high side of what we had been shooting for, it is there, and it would have been a bother if we had had to look forward to this for a very lengthy period of time; and I did, in fact, make two decreases of roll gain. I think that the fact that I did decrease the roll gain indicates how much bother it was getting to be. Reducing roll gain improved it. It didn't get rid of it, at the gain of 6, but it got down to an acceptable level, and I think possibly this time we are getting to where the q is starting to drop back.
Question: How did ball nose react during the flight?
Walker: The ball nose apparently worked right on the money also. Probably a good check of that thing will show up. I had to pull more than trim stabilizer at any speed to get above 10° a and this gets to be a bore as well as a chore when you are trying to fight something else. Cause as soon as you get it up there, and figure, well, I'll just hold this position and go look at something else, and you come back you're relaxed your wrist and it is back down there again. So this is another thing, I had to go to work and just pay attention to making the airplane fly at best L/D and set sail for home.
Question: Where did you notice the "stall buffet" you reported?
Walker: This was, I thought, in the vicinity of about 60,000 feet, around Mach 2 by the pressure indicator; I was at 240 knots and steady, essentially, indicated 8° a and neither the speed bleeding off nor the a changing, and all of a sudden it just went right into stall buffet, I thought. This kept it up, off and on, and I picked the speed up and it seemed to improve the situation, although later on, even at 260 knots this happened, and I finally began to wonder if we weren't running through atmospheric turbulence or something of that sort, even though it was up at that high altitude.
Question: What altitude, Joe?
Walker: Well, at or above 60,000 feet is where I started to run into that. It got to the point there for a while where when it kept up and I had increased the speed and it was still above the clouds, well above them, that I began to have some doubts about the aerodynamic integrity of the airplane. It bothered me a little bit that this kept up, so that's when I began to wonder if it wasn't turbulence we were running through. You can tell by (if you can) I don't know whether with the pitch damper out you can tell where I turned the switch off or not, but right at this point I turned the pitch damper switch off for a hack. Five minutes IFR time today.
Question: Did the engine start right away?
Walker: Yes, sir, Colonel sir, instantaneously, sir.
Question: Did the inflated suit bother you?
Walker: Other than the things I mentioned affected in reach or work load due to trying to bend out of shape those arms, no affect from suit inflation whatsoever. Sure had that cockpit cold, I had to crank the face plate up to medium heat setting because every time I started to talk I would get a slight film over the face plate and it blurred the instrument panel.
That radio deal
of yours, Jackson, you guys could apparently hear transmissions when they
had faded clear out, although you were complaining and obviously not reading