X-15 PILOT QUESTIONNAIRE

FLIGHT 2-34-57

September 29, 1964

Pilot - L/C R. Rushworth

RESUME

Purpose: To obtain data for the following programs:

1 Stability and Control Evaluation - (Glenn Robinson)
2. Advanced X-15 Landing Dynamics - (Jim McKay)

Instrumentation Engineer - Paul Harney

Launch: Mud Lake #1 on magnetic heading 170°, SAS Hi-Lo-Hi (8-4-8) ASAS Armed, heading vernier "Standby," both BCS "OFF," RAS "OFF," ventral off. Launch point coordinates: 38° 05' N; 117° 17.5' W.

1. Launch, light engine, increase to 100% T. Rotate at 10° a (» 2g) until q = 30°.
2. q = 30°. Maintain q = 30°.
3. Pushover to zero g. (H-dot » 900 fps).
4. Extend speed brakes to 35°.
5. Shutdown, retract speed brakes, increase a to 4°.
6. Disengage ASAS, disengage pitch damper, perform pitch pulse, engage pitch damper.
7. Disengage yaw and roll dampers, perform rudder pulse.
8. H-dot = -400 fps, increase a to 10'.
9. Perform rudder pulse. Engage roll and yaw dampers. Pushover to 5° a.
10. Disengage pitch damper, perform pitch pulse, engage pitch damper.
11. Disengage yaw and roll dampers, perform rudder pulse, engage roll and yaw dampers.
12. Disengage pitch damper, perform pitch pulse, engage pitch damper.
13. Disengage yaw and roll dampers, perform rudder pulse, engage roll and yaw dampers.
14. Disengage pitch damper, perform pitch pulse, engage pitch damper.
15. Disengage yaw and roll dampers, perform rudder pulse.
16. Extend speed brakes to 35°, pushover to 2° a.
17. Perform rudder pulse.
18. Perform rudder pulse. Engage roll and yaw dampers. Arm ASAS, vector to High Key, speed brakes as required.
19. High Key - check flap and "squat" circuit breakers in.

I. PRELAUNCH AND LAUNCH PHASE

A. Evaluate briefly flight performance of the following items during the prelaunch period and/or the launch maneuver.
1. Pressure suit operation - Good.

2. X-15 radios - Good.

3. APU's - Worked fine.

4. Damper system - Good checkout and worked.

5. Flow direction sensor - Good.

6. Launch transients (q, f, y) - No launch transients that seemed to be abnormal as far as I was concerned, I was holding a little bit of left stick in to maintain it, also when I grabbed the stick to put in left I put in a little pitch up and had to get that out before I launched.

7. Launch space positioning - Good.

8. Engine start - Fine.

9. Unforeseen incidents - None.

II. BOOST PHASE A. Evaluate flight performance in the following areas, during the "power on" portion of the flight.
1. Engine operation - Fine.

2. Roll and/or yaw out of trim indication - I didn't notice any roll or yaw to trim conditions except during the zero g boost phase the meter was over to the right (b needle was on the right-hand side indicating a nose left condition--it was over there about as much as it was off the other side before launch). I would guess that was probably the null position, one needle off, because when I dropped the airplane back it felt abnormal. I gave it a little kick to bring it back around 50 seconds. When I pulled it on up I came up to 10°, held it there, and as the airplane started to drop off I pulled the trim knob all the way back and didn't touch the stick at all until I came up on theta. Just before I got to theta I pushed the stick over and started to trim forward; theta came in real good. The ball was not indicating 30° - about a 5° error.

3. After I got into zero g - first thing at 4,000 feet/second I looked like I was a little low on profile and about that time I realized the g meter wasn't going to hit zero because I was already at negative angle of attack. It felt that I was a little negative so I pulled it back to alpha zero; at the 66 second point when I thought I was a little low I increased about 1/2°. Alpha should be about l/2° positive from there on out.

4. Unforeseen incidents - None - everything seemed normal. I was flying pitch vernier all the way through it.

III. GLIDE PHASE A. Evaluate flight performance in the following areas during the "power off" portion of the flight.
l. Burnout transients - None.

2. Roll and/or yaw out of trim indication - None - at this point, right at burnout, I didn't have any out of trim conditions. Everything was normal. The airplane was kind of sensitive with all dampers on, more sensitive in roll and side slip than the simulator was or that I expected. I rate that pitch - 2 l/2, roll 3 l/2 and sideslip 3. This was before dampers went off, at zero degrees angle of attack. There wasn't any controlling task. There was just maintain level attitude and trim back on up just before I started trimming up to 4° angle of attack.

3. Controllability following each pulse maneuver

a. When I turned the pitch damper off at a = 4° (it should come out at least 4° maybe 4 l/2°) I gave the first pitch pulse. I let go of the stick and there will be some short periods of time in there that I didn't have hands on the stick. I gave a small pulse and then increased it at the first half cycle. I gave it a little more boost then watched it for about 4 complete cycles. During that time I had hands off, then remembering that I was going to try to hold the stick constant in pitch, so that we could get any feed-in from the elevator, I grabbed the stick again and about the same time I got a small rolling tendency - a roll off. Which way? I don't remember now. When I grabbed the stick to pull the airplane back around it looked like it just wandered over to the other side so I maintained lateral control on the airplane. There was a short period of time when I first started that I had hands off. Worse than #1? The airplane seems to have a little less stability, even dampers on in roll and yaw, than #1 for the same mission. The pitch pulse - just watching it, I would give it about a 4 rating - I didn't try to control it - and give rating of 3 1/2 in roll and 3 in sideslip. Airplane response only in pitch and my control task of trying to maintain wings level in roll and no control task in yaw. There was no problem with the system when I engaged the damper in pitch - no transients or anything - it just grabbed on and stopped the oscillation real good.

b. I reached down and turned off the yaw damper and watched the airplane; I didn't see any transients or roll off or any out of trim condition. I shut off the roll damper and no transients and no apparent large roll off, although the airplane was very lightly damped. The minute I gave the rudder pulse the airplane started to follow the pulse and as it oscillated the other half cycle, it came back up level. Then as the nose swung back on the cycle in the opposite direction the airplane rolled over, and would have continued to roll, about the time I grabbed the sidestick. I'll rate that one in pitch - with no control task 2 1/2 all the way, and in roll, just watching the attitude and trying to maintain close to level flight, 3 1/2 and 3~ in sideslip. The airplane didn't handle any worse with dampers on than with dampers off. Into the pullup I turned roll damper on and, for some reason or another, started to give consideration to if we were going to have a problem it would come now. I don't think I had increased the angle of attack any more than 2° when the door dropped out. I spent probably 2 or 3 seconds thinking about that and reached down - I just left the airplane trimmed as it was - and turned on the yaw damper. I had just turned the roll damper on and started to pull up with the roll damper on - the yaw damper was off. When the door came out I didn't get any concerning conditions - it bobbled everything in all three axes. I was watching mainly the conditions that were going on in the cockpit rather than around the artificial horizon. I waited until the ball nose settled down by looking at the q meter-it was pretty erratic at the time. When that settled down everything was fairly normal in the cockpit except the standard airspeed Mach meter - that was jumping all over the place. I didn't have any trouble controlling the airplane. All the rest of the way home I will rate the airplane in pitch 2 1/2 for all conditions and control, speed brakes in and speed brakes out; in roll I will rate it 3 1/2, and in sideslip 3 1/2. This is with dampers on. There are all the control task of getting it home and rolling it up and bank angle so that I could see where the base was and evaluate my condition. It seemed like every time I rolled over, the airplane yawed and swung to an amount opposite to what the sideslip was at the time. Every time I rolled to the right the airplane would sideslip a little bit to the left and then swing back on over.

c. Controllability during the approach and landing - I think things were pretty normal. I was using about 20° of speed brakes all the way around - maintaining 300 knots. I would rate the control task in pitch as 2, in roll as 2, and in sideslip as 2.

d. Unforeseen incidents - Having to pull the gear lanyard twice to get the nose gear to drop out.