X-15 PILOT QUESTIONNAIRE

FLIGHT 2-32-55

June 25, 1964

Pilot - L/C R. Rushworth

FLIGHT RESUME

Purpose: Aircraft checkout and stability at low angles of attack.

Launch: Hidden Hills #2 on magnetic heading 227°, SAS Hi-Lo-Hi (8-4-8), ASAS ARMED, heading vernier (Standby) both BCS "OFF", RAS "OFF", ventral off. Launch point coordinates: 35° 58' N' 115° 39' W.
 

1. Launch, light engine, increase to 100% T. Rotate at 10°a (»1.8g) until q = 20°.

2. q = 20°. Maintain q = 20°.

3. Extend speed brakes to 35°.

4. Pushover to zero g. (H-dot » 800 fps).

5. Shut down, retract speed brakes, increase a to »4° to maintain 80,000 ft.

6. Disengage ASAS, Yaw and Roll dampers "OFF", perform rudder pulse. Roll "Lo," Yaw "Hi".

7. Pitch damper to low gain (4), perform pitch pulse.

8. Pitch damper "OFF", perform pitch pulse. Pitch damper "Hi".

9. Set up rate of descent of »250 fps.

10. Yaw and Roll dampers "OFF", perform rudder pulse. Roll "Lo", Yaw "Hi".

11. Pitch damper "OFF", perform pitch pulse. Pitch damper "Hi".

12. Cuddeback, extend speed brakes to 35°, increase rate of descent to »400 fps.

13. Yaw and Roll dampers "OFF", perform rudder pulse. Roll "Lo", Yaw "Hi".

14. Pitch damper "OFF", perform pitch pulse. Pitch damper "Hi", ARM SAS, vector to High Key, speed brakes as required.

15. High Key.


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 - Suit was real good.

2. X-15 radios - They were good during this portion.

3. APUs - O.K.

4. Damper System - It was normal and we got a good check.

5. Flow Direction Sensor - a and b appeared normal.

6. Launch Transients (q, f, y) - I did have a large transient in roll at launch. I didn't do anything in yaw. Pitch, I just pulled the airplane up and trimmed it from where I was to 5° angle of attack. (How was your controllability?) In pitch 1-1/2. I didn't do anything in yaw and although I got some sideslip as I came up in roll it wasn't any problem there. Controllability I'd probably rate about 2-1/2 in that sense.

7. Launch Space Positioning - O.K.

8. Engine Start - O.K.

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. q Control - It was real good except that I ran out of trim as expected. I was at full back trim and if I had to go to 30° of q I would have had to pull back on the stick.

3. Altitude Profile Versus Simulator - The altitude profile appeared to be very much the same as the simulator. Apparently I was getting to speeds sooner in the airplane and there was apparently an error in the system. I was getting my speed conditions about 100-200 fps before altitude and time.

4. Unforeseen Incidents - None

III. GLIDE PHASE A. Evaluate flight performance in the following areas during the "power off" portion of the flight.
  1. Burnout Transients - I had no burnout transients, everything seemed to be very good.

2. Controllability following each pulse maneuver - The first pulse I did at 4200 fps with speed brakes in, ASAS off, yaw off, and roll off, and hands off. I did a left rudder pulse and after 1-1/2 cycles I was 120° over on my back. The damping was pretty much as I expected and I just grabbed the stick and rolled it up level. The controllability was much better than I expected. Roll damping seemed to be a little bit better for putting in controls without the damper. I put the dampers back on then.

During the oscillations from the pulse, of course, roll was way out of trim and I'll rate it at about 2-1/2 in roll. (How about yaw?) I didn't make any control inputs in yaw, but it didn't seem too bad either. It was a steady state thing as I rolled around, no problem at all. (Did you have any trouble getting trimmed up to your angle of attack?) No, I was carrying, during this portion of it, 1/2° to 1° less angle of attack then what I expected. I was closer to 3° than 4°. Then, because I had gotten an altitude callout at this time that I was going low and I knew I must be going low because I rolled so far over, I pulled it on up to 5° and it seemed the rate of climb went right up to O and held there so I just left it all the way. The next series of pulses will be in pitch with the pitch damper at low. All the other dampers on normal. I'd rate that about 2-1/2 in pitch. (Is this controllability now?) No, this is just damping. Then another pitch pulse, damper off. I'd rate that about 3 in pitch. The damping with the pitch damper on low seemed to be less damped than the simulator. With the damper off it seemed to be as good or better than the simulator. I could give you a controllability rating there in pitch of about 2-1/2. I didn't think there would be much problem over all. It wouldn't be too hard to control 1-1/2 on both roll and yaw. Incidentally, all through the burning portion I didn't see any yaw oscillations at all as we have some other times. Once in a while we get steady state oscillations, small ones. (Due to this roll residual?) No, cause I was fighting roll all the way. The second pulse in sideslip would be at about 3600 fps. I was holding against the roll out of trim and I don't think there will be any stick motions in there until I've gone 2 or 3 cycles. It looked just like the simulator or a little bit better. I would say the airplane was a little more stable. Maybe the q was a little less. I was trying to hold it steady but I had to put in some left roll input to hold it steady. I don't think there are any inputs in there. With speed brakes out I did another pulse and it was normal and very much like the simulator. That must have been around 3,000 fps. I would rate it about 2-1/2 in roll and yaw and 1-1/2 in pitch. Then I turned roll damper and yaw damper back on. The next one was at 2,600 fps with pitch damper off. I gave it a pretty good pulse and let it go. It was normal and looked good. I'd rate that one about 2-1/2 in pitch. Roll and yaw were about 1-1/2, the dampers were on. I did one more sideslip pulse, I think, with speed brakes out and one more sideslip pulse with the speed brakes in or with the speed brakes at 20°, I can't remember which. I may have done them both. I'd rate them all about 2 1/2 with dampers off. Everything looked normal and like the simulator. Then I did the dampers all on, hands off roll and I got a right roll of 10-11°. I just let it go hands-off and see what it was going to be. Dampers on was no problem pulling it back. I'd rate it 1-1/2 in pitch, roll, and yaw.
 

Mach a Airplane Response Controllability q f y q f y
1. 4.3 3   4 3 1.5 2.5 2.5
2. 4.25 1     4      
3. 4.06 6.3 2.5     2.0 1.5 1.5
4. 3.90 5 3.0     2.5 1.5 1.5
5. 3.55 5       1.5 2.5 2.5
6. 3.14 3       1.5 2.5 2.5
7. 2.84         2.5 1.5 1.5
8. 2.50 4       2.5 2.5 2.5
9. 2.15 5.5            
10. 1.98 6            
11. 1.28 4            
12. 0.81 4           2
13. 0.56 9.2            
3. Glide Energy Management Versus Simulation - It was very close. Over the lakebed and subsonic I did a damper off yaw pulse and I didn't get very much out of the airplane. I would rate that 2. Then I did a damper off pitch pulse. I was feeling out the airplane and there was no problem there.

4. Controllability during the approach and landing -

q 1 1/2 , f 2 , y 1 1/2 .

Controllability during the approach and landing I'd rate as shown above.

5. Unforeseen Incidents - The out of trim in roll.
 

B. Describe and rate the most adverse piloting task experienced on this flight.

q 1 1/2 , f 2 1/2 , y 2 1/2 .

The most adverse piloting task was during the out of trim, damper off, roll condition. (The first pulse?) Yes, and I have already rated that as shown above.