2. Maintain 2g until reaching q = 38°.

3. Maintain 38° q to t = 40 sec, extend speed brakes.

4. T = 81 sec, shut down engine.

5. Retrim stabilizer to -12°dh (a » 10°).

6. At peak altitude (250,000 ft) bank 15° -30° to determine BCS control effectiveness.

7. H = 138,000 ft, trim stabilizer to -25° dh (a » 18°).

8. Reentry accomplished at a = 18°, An » 5.0, Ax » 2.4; q » 1,150 psf.

9. H = 68,000 ft level flight, vector to high key.

P.C.: The prelaunch was routine except that I never got around to turning on the launch switch light.

2, What indicated angle of attack was reached at 2g normal acceleration?

P.C.: I am not exactly sure what a corresponds to 2g normal acceleration, but I held between 13 and 15°a during this time (data shows a = 12° at 2g).

P.C.: Well, I imagine from the cockpit there really wasn't much difference between the planned and actual profiles. I overshot 3° on q when I was checking a and heading, but I had no trouble correcting bank to 38°q, within a degree, when I could concentrate on the pitch attitude.

When I put speed brakes out I oscillated ±2° about the 38° climb attitude.

2. Estimate Dq held, and rate the pilot task during the 38°q portion of the climb.

P.C.: See II.l. for Dq held.

The main pilot task is making sure the airplane remains on heading. I was using roll to make the heading corrections. There still exists a mismatch between the longitudinal stick trim and deflection which, for me, degrades the pilot opinion ratings. Pilot rating speed brakes in q 1.5 , f 2.5 , y 1 ... Pilot rating speed brakes out q 2 , f 2.5 , y 1 . The difference in rating with speed brakes out can possibly be attributed to the decrease in q, and not a speed brake effect.

3. Describe transients resulting from burnout and/or trimming to -12°dh.

P.C.: I don't think we were getting any particular asymmetry from the engine, however, burnout transients can be determined best from an engine shutdown due to fuel exhaustion. On this flight, I had to make a lunge for the throttle which certainly masked, by moving the longitudinal control, any small motions at shutdown. I was under the impression the damping in pitch was much the same before and after shutdown, but decreasing rapidly.

I was aware of the need for a small amount of left aileron during the climb, the da increasing toward the end of the burning time, It was just entering my mind it must be a small transient when we came to the problem of reaching for the throttle and the lateral out of trim disappeared. (The data show a. pitch oscillation, reaching about ±9°a, developed following engine shutdown. Pilot attempts to retrim to a lower a aggravated the nose-down motion. The motion subsided somewhat upon transfer to pure BCS pitch control.)

4. When did transition to BCS control occur relative to the burnout point?

P.C.: Transition to BCS control occurred shortly after engine cutoff.

P.C.: I had -12°dh on the trim knob, but was slammed down around 6°a by the pitch oscillation. The airplane probably would have stayed at 10°a, had it been able to seek its own level, but I was trying to do a control task and wanted to hold 6°a for awhile.

2. Were you able to sense the loss of dynamic pressure (q) during the coast to apogee?

P.C.: Even before engine shutdown, I was certainly able to sense the loss in dynamic pressure. ~

3. Do you feel an accurate awareness for a low q environment can be developed with flight experience?

P.C.: You can very easily develop an awareness for low q from one flight and practice on the simulator. The predominate cues are lack of acceleration with change in aircraft attitude plus the increased amount of control deflection required.

4. Which BCS control mode was used predominantly?

P.C.: I feel I was rather impartial today. Probably the directional BCS control was used most, based on the fact I was still using that one trying to damp the sideslip as q was starting to build up in the entry.

5. Were aero controls used as modulators to the BCS thrust?

P.C.: Aero controls were not used as modulators to BCS thrust after I reminded myself there was no sense fiddling with them. It's hard to break your habit of moving the aero control stick. (Data shows the pilot used the aero controls down to about q = 3 psf.)

6. Were BCS control inputs essentially "bang-bang" or was an attempt made to modulate the thrust levels?

P.C.: From some trial inputs I determined about how much control deflection it took to get a reasonable acceleration response. From then on I attempted to use that level as a means to apply a little more or less depending on the control task. Except in pitch, I don't think I banged the stops very often. You can modulate the thrust level very easily both with the amount of deflection and the period of input.

7. Were BCS control inputs essentially compensatory, or was an attempt made to lead the airplane motion?

P.C.: BCS control inputs were mostly compensatory except where I did the fixed attitude control task. I intentionally banked to 20° holding 6°a shortly after reaching the maximum altitude.

8. Describe the BCS vapor emitting from the nose of the airplane.

P.C.: I didn't see any BCS vapor emitting from the airplane nose rockets.

9. Could the airplane motion be detected from external cues? (Shadows, BCS exhaust, horizon.)

P.C.: Airplane motion can be detected somewhat from shadows moving around the cockpit, but once the airplane nose comes down, the moving horizon is a better motion reference. I noted that at apogee the lower edge of the windshield lines up with the apparent horizon when the airplane is at about 5°q.

10. To what limits could ^{·q, ·f,} and ^·y be detected on the 3 axis ball? Is this sufficient for precise attitude control of the airplane?

P.C.: Bank angle can be held within a couple of degrees up to ±30°q. This is due primarily to the 10°f increments marked on the 3 axis ball. Pitch angle is a little less accurate and I'd say ±4°q is about the accuracy limit unless you wanted to reset the pitch vernier. Control of heading would be about ±5°y due to lags in the ball presentation and airplane response to directional BCS inputs.

This attitude presentation from the 3-axis ball is sufficient for control from a safety-of-flight standpoint, but it would not be good enough for some of the planned future experiments.

11. In the region just before and after apogee were the a and b crosspointers, or the 3 axis ball indicator used for attitude control?

P.C.: The 3 axis ball indicator was used exclusively.

12. Do you feel the a and b crosspointers were recording true flow directions during the time at minimum dynamic pressure?

P.C.: No.

13. From this flight experience, estimate the attitude limits to which the airplane can be held using the present instrument presentation.

P.C.: ^·q ±4° , ^·f ±2° , ^·y ±5° . Also see III.10.

14. Rate the piloting task from the point of rotation to 10°a to apogee. Do these ratings adequately describe this wide range of flight conditions?

P.C.: q 3 , f 1 , y 3 . This isn't really a very wide range of flight conditions. However, you are better off after q goes completely flat than you are with a little q effecting the aerodynamics. (Range of flight conditions were: 144,000 ft < H < 250,000 ft, .9 < q < 64 psf, 4.4 < M < 4.7).

P.C.: I identified Monterey Bay, the Gulf of California, and well down the lower California peninsula. I couldn't see clear to the tip due to a cloud layer which I judged to be at about Mazatlan.

Los Angeles was really down under the nose and, as a matter of fact, I seemed to be rapidly coming up on the shoreline.

2. How sharply is the horizon defined at this altitude?

P.C.: The limb of the earth appeared very sharply defined on this flight.

3. Was the control task in any way different on the initial descending flight path from apogee?

P.C.: The control task was different but not during the initial descending flight path from apogee. It was different after q began to build up.

4. Indicate the change in pitch attitude during this time.

P.C.: I allowed the pitch attitude to go down below the horizon so I could orient myself with respect to Rogers AFB. As I came through 180,000 ft, I started to pull the nose up, remembered I didn't have full trim, and pulled up to 20°a by adjusting to maximum stabilizer trim. (Data shows pitch attitude decreased to about -20° during this period.)

5. Discuss and rate the pilot control task from apogee to the point of trimming to -25°dh.

P.C..: q 3 , f 1 , y 3 .. The pilot control task was about the same as the portion of the flight from shutdown to apogee.

6. Describe technique for sensing return of aero control effectiveness and transition from BCS back to aero control.

P.C.: The return of aerodynamic control effectiveness can be clearly identified as you arrive at the atmosphere, by the buildup in acceleration forces and airplane response to changes in pitch trim.

7. To what indicated angle of attack did the airplane rotate when the stabilizer was trimmed to -25°?

P.C.: The airplane rotated up to an indicated 20°a. (Data show angle of attack to be in the range 16° < a < 20° during the entry maneuver.)

8. Discuss and rate the reentry control task.

P.C.: I want to break this discussion into two parts -- the reentry below 4g, and above 5g normal acceleration. When the maximum stabilizer trim did not pull the nose higher than 4g, I had a considerable lateral-directional control problem. As I pulled on up above 4g the control task just went away as soon as the sideslip became less than 2°. I held the airplane at 5g and 20 a for a while, and when I decreased normal acceleration it was to keep the nose on the horizon, and not to keep from exceeding the "g". (Data shows the pilot held 5g for about 5 seconds before reducing a as the airplane came level.) Pilot ratings below 4g - q 2 , f 3 , y 4 . . Pilot ratings above 4g - q 1 , f 1.5 , y 1.5 .

Simulator ratings would be about the same because the flight characteristics did not appear to be a function of normal acceleration. (Data shows the dynamic pressure varied between 75 < q < 1000 psf during this period.)

9. Could you detect any temperature buildup in the cockpit area?

P.C.: No, I was cold the entire flight today.

10. Were you aware of any restriction in breathing during the reentry?

P.C.: No, I was not aware of any restriction in breathing during the entry. The g-suit was really bearing down on me and I noticed a slight prickling sensation in my legs. I may have held my breath a little to help out the g-suit.

ll. To what limits would you be willing to maneuver the airplane under the reentry conditions experienced?

P.C.: I don't know whether I would want to maneuver the airplane much other than what it is doing by itself. I would be able to pull it into a banked turn to correct the course, but I would not wan to apply pulse maneuvers, etc.

P.C.: Ground control was adequate once I regained communication with NASA 1. They told me my position, I looked out and verified it, and that's all there was to it.

2. Discuss and rate the piloting task from recovery to level flight, to high key.

P.C.: The pilot task to high key was no problem at all. q 1 , f 1 , y 1 .

3. Estimate the total amount of "pilot effort" expended on this flight up to the high key point, as compared with previous flights.

P.C.: I put more effort into flight 1-26 than this one because of the number of maneuvers required. More pilot effort was required during the pullout this time, however, due to the magnitude and duration of the acceleration forces on the pilot.

4. Do you feel additional reentry flight experience will tend to reduce the level of "pilot effort" to that experienced in flying any high performance airplane?

P.C.: Additional reentry flight experience was certainly a help. I think a lot depends on the amount of sideslip that must be compensated for as dynamic pressure increases. This is going to have an overpowering effect on the pilot effort required over and above just withstanding the acceleration forces.

5. Did the fixed-base simulator provide adequate preparation for this flight task?

P.C.: Yes, the fixed base simulator did provide adequate preparation for this flight. Ample practice time was available to anticipate, and provide for, a number of emergency conditions.

P.C.: There were no non-routine items during the approach and landing. The landing was quite normal.

2. Please rate the pilot task during the landing approach and the landing flare.

P.C. : q 1 , f 1 , y 1 .approach.

q 2 , f 1 , y 1 .landing.

The higher rating in q on landing was due to the side stick force and trim characteristics.