2. Maintain 2 g until q = 25° - maintain q = 25°.

3. Extend speed brakes - pushover to a = 2° (g = .2)

4. Shut down engine - disengage roll and yaw dampers, perform dv pulse.

5. Disengage ASAS - pullup to a = 15°, perform dv pulse. Increase a above 15° at pilot's discretion.

6. Peak altitude - continue pulses at pilot discretion.

7. Retract speed brakes - pullup to a = 20°, perform dv pulses.

8. At pilot's discretion pullup to dh = -35°.

9. Pushover to a = 13° - vector to high key - perform dv pulses during deceleration.

10. Reengage SAS and ASAS - Jettison.

P.C.: There didn't seem to be as severe a roll-off as I have seen in the past, however I was a little bit surprised when the roll SAS light came on. When something of this nature happens it takes away tremendously from your concentration on the initial profile which is very important. You are sailing out with a lot of thrust and you should be concentrating on the angle of attack which is very important at this time. If you get the first part of your profile down, the last part's essentially going to take care of itself. It took three of four reengaging attempts to engage roll SAS. I wanted to do this so I would have a good SAS backup when things began to get weak above Mach 5.0.

Roll SAS only went out and I nearly went on ASAS. It was automatic as I had ASAS armed, so it was just a little problem of trying to reengage the normal roll SAS and getting ASAS armed again. I wanted to get ASAS off the line and back on the regular roll SAS channel so we could go on with the flight plan.

B. Was engine start normal?

P.C.: Then the start was normal. I heard NASA-l saying that it was a nice blast off.

C. How well was 2g rotation maintained?

P.C.: I didn't hit 2g. I don't know why they put 2.0g on the flight plan, but I was hitting anywhere from 1,6 to 1.8g. I never hit 2.0g on the pull-up to 10° or 12° a. I think if I were to hit 2.0g we would really go quite a bit too high on profile. I'd say 1.6g is more normal.

D. Was 25°q achieved and maintained easily?

P.C.: Yes, after I settled out on it. When I finished with this SAS business, I looked up and was at 5°a. I pulled up to l0° a and then checked my q vernier and found out that I was heading up about 28°, somewhere in this vicinity, so I pushed over again. It oscillated but I think the average came out to be about somewhere around 25°q. Pitch damping appeared to be good here with no oscillation once you settled out and got the trim set up.

q 2 , f 2 , y 2 .

P.C.: This was real simple, other than the SAS switching problem, I'll rate it as shown.

B. Was the climb normal?

P.C.: The climb was normal.

C. Comment on the effectiveness of ground control during launch - rotation, and climb.

P.C.: Ground control was very good this time.

D. Comment on burnout transients.

P.C.: I didn't get a heck of a lot of deceleration, of course I was at very low q this time and still going uphill. I fly without the head bumper and my shoulder straps are out almost of the limit so I can reach things in the cockpit but I had no trouble banging my head against the canopy or anything of this nature. In fact, right after burnout I could move around freely.

E. Describe effects of disengaging roll and yaw dampers on the control system and response of the aircraft.

P.C.: Disengaging roll and yaw dampers, to transfer to ASAS damping, did not effect the airplane at all.

P.C.: The data shows the airplane response to two small rudder inputs to be a neutrally damped directionally oscillation.

B. How did the airplane respond to having ASAS disengaged?

P.C.: The airplane didn't respond at all, when I disengaged normal yaw and roll dampers, but of course I still had ASAS on, which is a roll and pitch damper. It just seemed to be steady as a rock, but when I put in a rudder kick the airplane just seemed to diverge out and at this time I don't think she hit over l.5b, if that.

From then on, from about M = 5.2 on down trying to hit certain angle of attack increments and doing these rudder kicks the airplane was just oscillating freely. I really can't say that at any time it looked divergent in yaw and certainly it wasn't in roll. The roll excursions were very much less than what the simulator showed, but yet because of the motion cues I sensed that the airplane actually wanted to go out in yaw. The data shows an undamped directional oscillation did develop with ASAS damping
 
 

I never did turn ASAS back on because I thought the airplane was getting too squirrelly or that it wanted to take off. I did turn ASAS back on to try to get the airplane steadied down so I could do another rudder pulse. At one time I saw 18°a.

As far as the airplane response to disengaging ASAS, it appeared that in some cases ASAS aggravated the situation somewhat. I really didn't see too much response to it as far as any damping when I reengaged ASAS. Of course, the pitch was constantly providing damping, but at one time there the ASAS actually made yaw diverge out to about 6°b and I had a pretty healthy oscillation going this time in yaw.

During this time the roll excursions I would say were not more than 15°. I never did get the 45° roll-off such as Rushworth experienced.

C. Rate at a = 15°. M » 5.0. q 3.5 , f 3.5 , y 3.5 .

P.C.: I pulled up to 15° a and the ASAS was on and I cut it off. I don't remember now whether I got a rudder input. A lot of times I would try to get the airplane steadied down and as many times as not I parlayed the rudder input because the airplane was oscillating pretty hard to begin with. Really at no time did I need a rudder input because it was oscillating pretty healthy to begin with.

The airplane appeared to follow somewhat the simulator in that the higher you went the better it damped. I got this impression, and roll was never a problem. At this time, I can particularly say that roll was never a problem to the standpoint that I had to sit there and fight it.

It seemed like that when pitch steadied down it didn't have a tendency to oscillate but if I would try to make a little control movement the pitch would go, it would just seem to oscillate at 10 - 15° and this was very uncomfortable. I couldn't steady down on any one angle of attack and would have to start over again and work back up again. I felt I would have liked to have more pitch damping all through the flight. Of course, the q was very low. I don't think I read more than about 125 q at any one time. I'll rate the control task both when the airplane was steady and when it was oscillating in pitch, as shown.

D. Enumerate the dv pulses you accomplished during the interval between ASAS disengagement and speed brake retraction. Comment and rate the pulses completed. What was maximum angle of attack?

P.C.: It's hard for me to say right now, just how many I got. I can't remember whether I got rudder kicks when I was steadying up the airplane. I just let the airplane oscillate. I think we will have to go to the records. I don't see how you could rate them really. Maximum angle of attack was about 18° from what I saw.

E. Rate task to set up airplane for dv pulse at a = 20°, M » 4.5 with speed brakes closed. q 3.5 , f 3.5 , y 3.5 .

P.C.: I never did get to 20° a. I didn't see a lot of difference between the higher Mach numbers and the lower Mach number, brakes closed. I was doing these pulses all the way down and at no time did I ever have to go to ASAS to really stabilize the airplane because I thought it was getting away from me. It was only to get the airplane damped down to where I could get a decent rudder input, but by the same token, the dampers didn't help me any. I'd rate these as shown.

F. Rate dv pulses at a = 20°. M » 4.5, speed brakes closed.

P.C.: When I closed the speed brakes, Edwards was coming right over my nose and I got a call from NASA 1 that I was close in. I don't think I had the speed brakes in for what -- maybe 30 seconds -- it might be longer, but I began to put them out again because of energy management. I had to drop quite a bit of the flight plan because of the ranging. I think this is the type of flight plan that we could achieve better if we come out of Smith's Ranch.

G. Rate pilot task to pullup to dh = -35° and estimate conditions.

P.C.: I didn't get to 35° stabilizer for this reason. When it looked like I was having a little trouble holding my pitch trim, I elected to go ahead and put in some stabilizer trim and then use force, then if she began to really oscillate I could let up on it. I rolled in back trim and let the thing diverge up to 23° a but I elected not to go this route.

H. Rate and discuss the dv pulse at a = 13°. M » 3.4.

q 2.5 , f 2.5 , y 2.5 .Was the response of the airplane to this pulse normal? Compare airplane to simulator.

P.C.: These were mostly with dive brakes out. I got very little time and I would say it was probably more like 12° a coming back in. At M » 3.5 I had dive brakes in and was setting up for the energy management profile back to the field. I saw the field come under the nose and from then on everything was just getting back in and making the turn but I'll rate the controllability as shown.

P.C.: The only pulses I got during the glide to high key were a series of sine waves with all the controls for the RAS checkout. SAS was on at this time.

B. Was reengagement of SAS and ASAS normal?

P.C.: SAS and ASAS reengagement was normal. I made my high key a little bit higher than normal. In fact, I started down and I think I hit high key about 45,000 feet.

P.C.: I started in about 18,000 feet on the base leg still indicating about M = 1.1 or 320 knots and went down to about 315 knots and from then on I held this all the way down. It felt very comfortable, in fact, I think this is the way to do it. If you have to hit a small lake bed with a lot of altitude and a lot of airspeed, bleed off in an S-turn, put your brakes out and you can drop like an elevator.

B. Describe directional controllability during landing run.

P.C.: During the landing run, I got my nose gear in one of those ruts on the runway. It was just a series of directional sine waves down the runway.

C. Was a spot landing accomplished?

P.C.: I hit the two-mile marker again.

D. Was subsonic buffet experienced on this flight?

P.C.: A vibration was observed but I wasn't getting it through the control system. The clock sitting up there, however, was just a blur. I noticed this on the last flight. I think the last time I noted it at about 240 knots an somewhere near 48,000 feet. Today, it was about 45,000 feet at 280 knots so I don't know whether or not we can define the envelope of this vibration. It just feels like the buffet you'd get before you pitch up in an F-86.

I may have had some speed brakes out this time but by the same token, the last time I experienced this vibration, chase reaffirmed that the speed brakes were in. Also, before the last flight, we found that there was some play in the joints that hold the actuators to the speed brakes and they tightened these.

It's kind of a low amplitude-high frequency sort of thing and I can't tell you what frequency it is. Something over 40 cycles per second, I'm sure. I'm just taking this from the X-lB days when we could barely feel 40 cycles per second. This seemed to be at least twice that frequency but very low amplitude.

P.C.: I could have flown the whole flight without ground control really, but it is nice to know your timing is coming out the same. NASA 1 seemed to be a little early giving me the call to shutdown. I shutdown the engine at a little over 80 seconds. You don't think one second can make much difference but you're watching that clock forever and a day before you grab something. I might be wrong, but when I shut down NASA 1 was reading off the last three seconds. I don't think NASA 1 ever got to the shutdown word.

As far as the climb or actually as far as the flight's concerned, the visibility was so good, and the cues as far as inertial readouts seemed to be the same as the simulator had given us so I don't think I had to rely too much on the ground control, although they were certainly there for that purpose.

B. Comment on any distractions or unusual occurrences during the flight.

P.C.: Well, I would consider on the climbout the SAS reengagement problem, and after shutdown the wallowing, etc., that took place as distractions which contributed to complicating the flight plan.

C. Do you feel you had sufficient range to adequately complete your mission?

P.C.: Actually I don't think we did complete the mission. I think I could have used another 50 miles range and as a consequence I had to delete a portion of the planned tests. I think that I could have gotten to a somewhat higher angle of attack although at a lower Mach number if there had been sufficient range available before setting up for the landing.