FLIGHT 2-21-37

Pilot - Major Robert White


1. Launch using side stick, light engine to 100% thrust, SAS 8-6-8, and rotate to a = 10°.

2. Maintain 10°a to pitch angle q = 25°.

3. Maintain q = 25°, pushover to zero g at 48 sec from engine start.

4. Accelerate at zero g to engine burnout (approx. 83 sec).

5. Set SAS 8-0-0 and perform rudder pulse.

6. Extend speed brakes and increase angle of attack to 10° < a < 15°. Evaluate handling qualities using b-dot control technique.

7. Reset SAS 8-6-8, retract speed brakes and perform pushdown-pullup over a range from 0 to 15°.

8. Extend speed brakes, set SAS 8-0-0 and continue b-dot control evaluation in a = 10° to 15° range.

9. Reset SAS 8-6-8, turn to high key using speed brakes as required.

10. Perform pushdown-pullup at M = 0.8.

I. Launch

A. Please discuss any unforeseen airplane motions or system failures resulting at launch.

P.C. The launch was the same as usual. I don't think there are any pertinent comments to make on this launch. There were no system failures.

II. Climb A. Please note differences between planned climbout profile and actual flight profile.

P.C. On the rotation I had 10°a or perhaps a little bit better and felt I was pretty well pegged on it. I pulled up and bobbled around 25°q but again felt I was right on all the way. As far as I was concerned in the cockpit, I should have been right on the planned climbout profile. As I rotated into the climb, however, the sun was shining right in my face and I had to shield my eyes with my left hand in order to get a better look at the cockpit gages. This situation may have produced some pitch oscillations during the initial rotation.

III. Speed Run A. Please describe airplane handling qualities to Vmax.

P.C. Handling of the airplane to Vmax at zero g was no different from what I have experienced in the past. (Handling characteristics have been very good during this portion of the flight.) I did have the stabilizer trimmed out during the speed run. I wasn't impressed by any airplane motions at burnout. The shutdown seemed to be a little bit different this time -- compared with a shutdown by closing the throttle -- it seemed to occur over a longer time interval. However, this delay did not upset the airplane trim.

B. Please rate pilot task to Vmax. Rating No. Pitch 1 , roll 1 , yaw 1 .

IV. Deceleration, SAS 8-0-0 A. In the speed range 3.2 < M < 6, please describe airplane response as a function of angle of attack, and adequacy of the control technique.

P.C. After the speed brakes came open, I increased angle of attack and it was very slow at first. I suppose you are not as handy at elevating the angle of attack in the airplane as you are in the simulator. I was impressed that it took me a lot longer to get to 8°a. I had the airplane pretty well trimmed out, but I suspect I may have been holding a little bit of back stick. I pulled up to around 8°a without experiencing any control problem and was content to just sit there without making any input to the control. I satisfied myself you can fly along under these conditions without picking up motions which require corrective control action. One or two times I started getting some sideslip when I pulled back just a little bit to increase a. Corrective control (aileron) was applied to stop the directional motion, but at no time did I get into a situation where I really had to start forcing the airplane around -- or apply the b-dot technique to stop the motion.

B. Rate pilot control task - Rating No. in pitch 2 , roll 3 , yaw 3 .

C. In speed range 2 < M < 3, please describe airplane response as a function of a, and adequacy of b-dot control technique.

(The second dampers-off pullup was terminated following failure of the right windshield outer panel. The data show piloting inputs and airplane response to be very similar to the first, higher speed, period. Peak indicated a reached was about 7°.)

P.C. I turned dampers off (8-0-0), put speed brakes out, started to come up in angle of attack, and the windshield cracked -- all at once. This failure was worse than the earlier incident (flight 2-20-36) for there was no visibility through the right windshield at all. It was not too long after this that I reached down and turned SAS back on. The directional oscillation experienced was of little concern. I don't think you get excited unless it becomes larger than about 2° (b). (Measured bmax » 1.5°).

D. Rate pilot control task in this speed range - Rating No. in pitch 2 , roll 3 , yaw 3 .

V. Landing A. Discuss briefly flare initiation noting in particular altitude and airspeed.

P.C. The landing was pretty much as usual except for the limited visibility which came as a surprise. In the landing, I felt I must have been at least 2 seconds behind in making corrective control inputs. For instance, when the flaps went down and as I flared, and then the trim change taking effect and the altitude change, I was 2 seconds behind on the control to prevent the airplane from ballooning. It ballooned quite a bit higher than it had on previous flights.

It's pretty obvious now that both windshield panels are required because I had the impulse to move over to use both eyes through the one clear panel. But, of course, with the restricted head room you can't move over. Perhaps on this landing, my depth perception was compromised a little bit -- but not completely, since I still had both eyes operating even though one windshield was opaque.

I think the black lines painted on the lake surface make a tremendous difference as far as aiding your depth perception during the final approach. It wasn't apparent that this restricted visibility was offering any problem until the roll out onto final and all of a sudden one black line started to disappear.

On final approach, I was fairly high, even after the gear came down, 90 I held it and let it settle with a pretty high sink rate. At the last minute, I made a control input much sharper than I ever have at a point that close to touchdown. The control change arrested the sink rate and a fairly normal landing resulted.

B. What was intended touchdown point?

P.C. The second chevron was the intended touchdown point.

VI. General Comments A. Please outline items which in your opinion modified or prevented, the fulfillment of this flight mission.

P.C. Other than the windshield incident, nothing occurred during the flight which compromised completion of the mission.

B. Please note any areas where the fixed-base simulator did not predict airplane response.

P.C. The simulator gave me a good clue as to what I could expect during the flight. I wasn't impressed that anything unexpected was experienced compared with the simulator preparation.

C. Please extrapolate the SAS-off experience gained on this flight to forthcoming reentry conditions.

P.C. I feel I could have gone to a higher a, but I would have started working to control the airplane. I believe it is more significant to determine the limiting a where the airplane is behaving well with the pilot making only the smallest corrective control inputs. You cannot fly the airplane at an angle of attack where you will be required to make control inputs to damp airplane oscillations and at the same time contend with the rapid buildup in dynamic pressure and normal acceleration. I think you are going to lose the airplane under those conditions.

I think 10°a would be the limit above which the pilot would fast become dissatisfied with the airplane control characteristics -- in the reentry environment.


Typed: 12/4/61