X-15 PILOT QUESTIONNAIRE

FLIGHT 2-19-35

Pilot - Commander Petersen

RESUME OF FLIGHT REQUEST

1. Launch using side stick, light engine at 100% thrust, rotate to 10°a.

2. Maintain 10°a until q = 30°.

3. Maintain 30° q, pushover to zero g at 31 seconds.

4. Reduce throttle to 50% thrust at 68 seconds and extend speed brakes.

5. At T = 72 seconds, V = 4,800 fps, roll into 80° left bank and maintain until burnout.

6. Burnout. After burnout roll to 80° right bank, maintain 10°a.

7. At V = 4,300 fps, increase to 15°a and perform rudder pulse.

8. Roll out of turn on heading of 220°, reduce to 5°a, set SAS 8-0-0, evaluate controllability.

9. At V = 3,000 fps, reset SAS 8-6-8, retract speed brakes, perform pushover-pullup 0-15°a.

I. Launch - Climb - Pushover

A. Launch 1. Please comment on side vs center stick characteristics during recovery from launch. (Include effects of correcting initial roll motions, acceleration effects, control of airplane during rotation.)

P.C. There was no difference in the airplane using the side versus the center stick during recovery from the launch maneuver. The side stick was held loosely. The roll motions of launch were not compensated for until after the airplane was completely away from the flow field of the B-52.

2. Please describe longitudinal trim techniques used for climb. Do you feel this is optimum? Was transonic trim change noticeable?

P.C. On the simulator trim was used as primary longitudinal control for the climb. In the airplane force was held and then trimmed to a at about 10°. This appeared to be an optimum technique. Transonic trim was noticeable and caused some a variation in round up.

3. Please rate airplane for launch, recovery, initial rotation period.

P.C. Simulator: pitch 3, roll 3, yaw 3.

Airplane: pitch 2, roll 3, yaw 2 .

4. Rotation: Airplane Simulator

P.C. a = 9° ± 1° 10° ± 1°

q = * 30° ± 1°

f = 0° ± 10° 0° ± 20°

* Initiation of pushover was coincident with the approach to a 30° climb attitude.
B. Climb 1. Please rate airplane during climb.

P.C. Rating for airplane: pitch 2, roll 3, yaw 2. Rating for simulator: pitch 3, roll 2, yaw 2. The simulator appeared to be stiffer in roll than the airplane.

2. Were any lightly damped airplane motions noticeable?

P.C. There were no noticeable lightly damped airplane motions.
 

C. Pushover - Zero g Flight
  1. Please rate airplane at zero g pushover.

P.C. Rating for airplane: Pitch 2, roll 4, yaw 2 . Rating for simulator: Pitch 2 ,roll 2 yaw 2 There were no lightly damped airplane motions nor any structural vibrations.

II. Throttling Action A. Please describe sequence of events in reducing throttle and extending speed brakes including pilot scanning of instruments.

P.C. Simulator: Begin establishment of 75° bank angle at 64 to 65 seconds. Altitude was primary instrument at 68 seconds. Reduce power to 50% followed by full opening of speed brakes.

Airplane: At 4,800 ft/sec throttle was reduced to 50% and the speed brakes were opened. With the speed brakes open enough trim for about 2g was applied and the pullup was completed using longitudinal force. A bank angle of 65° was attained with the opening of the speed brakes.

B. Rate airplane pitch 3, roll 3, yaw 2. Simulator pitch 2, roll 4, yaw 2.

C. Were any inadvertent control inputs or problems noted in the longitudinal mode?

P.C. There were no inadvertent control inputs. In establishing 3 1/2g I overshot to 4g and back to 3 l/2g and held that to burnout.

III. Roll Maneuver A. Power On 1. Describe sequence of roll and pullup.

P.C. Simulator: Bank angle has been established. Trim longitudinal input for about 2g and manually increase g to 3 1/2. Note a and lock on. Monitor a, f, q, H (inertial), V (vertical), and V (total). a is the critical parameter.

Airplane: Holding 10°a, I changed from about 65° left wing down to 75° right wing down, increased the angle of attack to 15° and held it there for several seconds and then did a rudder pulse.
 

(a) Was roll power adequate?

P.C. Yes, I feel it was.

(b) How much da was used?

P.C. I used half available.

(c) Constant input?

P.C. No, it was not a constant input.

(d) Estimate Pmax.

P.C. I have no idea what Pmax was.

(e) Any b noticed?

P.C. There might have been about 1° of b.

(f) Was roll stopped before a increased?

P.C. Simulator: f - +75 to 75°. Airplane: f = 65° to +75°. Roll was stopped before a was increased to 15°.
 

2. Was any lateral or longitudinal force held?

P.C. Simulator: Longitudinal force was held except for bank angle correction. Airplane: No lateral force was held. There were no indications of spiral divergence. No forces were required to hold the bank angle. The a was changed by using longitudinal force.

3. Were any heating effects noticed?

P.C. No heating effects except the smoke in the cockpit. There was no creaking or popping noises. This may have been because there was normal acceleration on the airplane.

4. Was a lowering in directional stability due to high a noted.

P.C. I did not notice any lowering in the directional stability. It seemed solid as a rock.

5. Were any lightly damped airplane motions noticed? Were any structural vibrations felt by pilot?

P.C. I should not say it was solid as a rock, there were some motions, but none that would concern me.
 

B. Power Off 1. Were any burnout effects on airplane motions noticed?

P.C. There were no burnout transients.

2. Describe roll to right bank (da input, max rate, any coupling, was a held constant?)

P.C. Simulator: There was some reduction in a going through zero bank angle. Angle of attack was increased to 15° at 75° right wing down using force plus longitudinal trim for about 2g. Airplane: I did not want a high rate of roll. It seemed to bank a little bit easier than it did on the simulator.

3. Rate airplane at 10°a power on.

P.C. Airplane: power on - pitch 3, roll 3, yaw 2.

power off - pitch 3, roll 3, yaw 4.

Simulator: power on - pitch 4, roll 4, yaw 4.

power off- pitch 4 roll 4, yaw 2.

IV. High Speed Flight at 15° 1. Describe technique used to obtain a = 15°. (Was full trim used and was it sufficient?)

P.C. See answer to III-A.1.

2. Rate airplane at: a = 15°, SAS 8-6-8.

P.C. Airplane: Pitch 4, yaw 2, roll 2

Simulator: Pitch 6, yaw 2, roll 4

3. Describe airplane motions at a = 15°.

P.C. There were no motions that I did not induce.

4. Describe airplane response to rudder pulse.

P.C. On my indicator the pulse was deadbeat and there was about 2° of sideslip.

V. Flight at SAS 8-0-0 1. What a was set up before SAS was turned off? Were all forces trimmed out?

P.C. Simulator: Angle of attack was 4° and SAS was set at 8-0-0. Increase a to 10°. Rudder pulses as required to establish directional oscillation. Sideslip well damped. More dv pulses required to maintain b oscillation. Normal lateral control technique used. Airplane: Angle of attack was at 4° before SAS was turned off and all forces were trimmed out.

2. After SAS off describe build up of motion.

P.C. Simulator: bmax ±4°, fmax ±4°, a ±0°, lateral period 2 sec., long. period l sec. Airplane: bmax ±2°. There was one point where I reached for the roll damper. I wanted to be near it because suddenly the airplane became real sensitive in roll. The airplane would want to roll off one way or the other when I flew hands off but you could bring it back by normal control. I think there was some associated with this, but it was quite small and it was roll displacement that I was concerned with more than the yawing, I think I was at about 9° angle of attack. I got the nose of the airplane pointed down at about Mach 4 with dampers off from about 4°a with the thing coming downhill definitely, I increased angle of attack to about 9°. I must have sat there for about a minute and a half. I rolled the airplane 45° a couple of times.

3. Rate airplane before pilot control attempt.

P.C. Pitch 2 1/2 to 3, roll 3 1/2, yaw 3 1/2.

4. (a) were fixed controls or hands off flown?
 

P.C. I flew a combination of fixed control and hands off. I put in motions whenever I wanted to. There was no tendency to put in motions that I did not want to put in. I was not subjected to any accelerations or oscillations from the airplane.

(b) Were any conventional techniques used to control the airplane motions?

P.C. I used conventional techniques only. There was no necessity for the b-dot technique.
 

5. Was b-dot technique used?

P.C. No.

6. Was a changed?

P.C. 4° to 9°.

7. Were motions similar to flight 1-22-37 with dampers set at 8-0-0?

P.C. Here are the following differences: On the other flight I used the center stick and on this flight I used the side stick. On the other flight I was down around 70,000 feet and on this one I was probably around 80,000 feet. Also, there was a difference of ship. No. 1 last time and this time it was ship No. 2. On the last flight I had residual fuel on board and on this flight I did not have fuel on board. On the last flight the suit inflated, and on this flight it did not.

8. Describe accelerations imposed upon pilot by airplane motions? Did they compromise or influence the use of the side stick?

P.C. There were no accelerations.

9. From this flight experience, how useful is b-dot technique for extended emergency operation of airplane? Was side stick a help or hindrance?

P.C. The b-dot technique was not required for control of the airplane on this flight. The side stick control appears to be a help.

10. Please compare emotional stress level of this portion of flight with launch and landing.

P.C. Normal emotional stress levels were experienced during this portion of the flight. Higher levels of stress were felt during the power-on portion of the flight.

11. Did kinesthetic motion cues complicate the airplane task compared with the fixed-base simulator?

P.C. Motion cues did not complicate the airplane control task compared with the simulator,

12. Please note any other distracting factors which complicated optimum airplane control during this portion of the flight .

P.C. The only distracting factor noted would be the brief period when smoke filled the cockpit and prevented a clear view of the instrument panel.

VI. Landing A. What cues were used for determination of flare initiation?

P.C. Cues used were altitude and visual reference with the ground. Observed altitude was on the order of 500 feet.
 

1. Flare initiation point: Vi = 300. Hp = 2800.

2. Describe flare initiation point relative to ventral jettison and flap actuation.

P.C. Flaps were lowered at 2,500 feet altitude and ventral had been jettisoned before flare initiation.
 

B. Was an aiming point used prior to the flare? Please describe technique used?

P.C. An aiming point was used up to the point of flare initiation. The aiming point was the one-mile marker on the runway.

C. Was a spot landing attempted? How far from planned point was touchdown?

P.C. The planned touchdown point was the two-mile marker. Flaps and gear were deployed easily to shorten the glide, with the result that the touchdown was short of the desired landing point.

D. Were flight controls used successfully for runout control?

P.C. The airplane tended to slide off to the left during runout and the flight controls were used to help hold it on course.

VII. General Observations

A. Sidestick

1. Was stick configuration adequate?

P.C. The side stick configuration is adequate as regarding position and comfort. I would like to see a little additional wrist support.

2. Did the trim button work alright?

P.C. Trim button worked fine.

3. Were stick forces and centering adequate?

P.C. Force and centering characteristics appeared to be good on this flight.

4. Was stick displacement sensitivity adequate?

P.C. I would rate the stick sensitivity as adequate to good.

5. Were there any inadvertent inputs or combination inputs?

P.C. I believe I had no inadvertent inputs and very few combination inputs.

6. Was overall airplane response to side stick inputs satisfactory? Were there any phasing problems?

P.C. The airplane response to side stick inputs was very satisfactory and there were no phasing problems.
 

B. Please note the major deficiency during this flight.

P.C. The major deficiency noted on this flight would be the lack of clear radio communication.

C. Other than kinesthetic cues, please note airplane control characteristics which were not encountered on simulator.

P.C. On this flight the airplane responded very closely to the motions predicted by the fixed-base simulator.

D. Any comment on ground control?

P.C. Except for radio communications, ground control was excellent during this flight.