Pilot - Joseph Walker

General preliminary comment: 1. Pitch SAS mode failed at engine start and could not be reengaged.

2. Roll SAS mode was reduced to, and remained at, a 4 setting just prior to the power-off rotation to a = 12°, 14°.

I. Launch A. Rate pilot task required to recover from launch and establish a = 7° trim attitude.
  1. Rating No. in pitch 5 , roll 5 , yaw no correction required.

Pilot Comment: (Pitch SAS mode failed at engine start and could not be reengaged.) Pitch SAS malfunction after engine start reduced longitudinal controllability and required constant pilot attention.

B. Rate airplane damping in pitch 7 , roll 3 , yaw 1 .

Pilot Comment: Low damping made control difficult and demanded considerable pilot concentration. Also, excessive attention was needed to keep wings level with roll SAS mode inoperative.

C. Please comment on side vs. center stick characteristics during recovery from launch.

Pilot Comment: Center stick is superior to side stick for longitudinal accelerations experienced to date. Side stick displacement is over sensitive in pitch. Also, back stick required to trim airplane is greater than wrist movement available, necessitating raising the forearm to a cramped position. Lateral side stick displacement and force gradient is low relative to pitch axis. Positive roll centering is hard to determine, particularly when holding longitudinal force. Movement of trim knob usually produces unwanted lateral control motions. Trim button would be more acceptable to pilot.

Side stick displacements and forces on simulator are representative of airplane .

II. Climb A. Rate pilot success in performing q = 30° climbout.

Pilot Comment: Climbout was made at q < 30° due to preoccupation with SAS pitch mode failure and residual roll oscillation.

1. Rating No. in pitch 5 , roll 3 , yaw 1.5 .

2. 30° pitch attitude held within ± °?

Pilot Comment: Below range set on pitch vernier.

3. Wings held level within ±l0°.

4. Was vernier presentation adequate? (See .II.A.2.)

B. Pilot's attention was directed principally toward first pitch, and then roll.

Pilot Comment: SAS roll residual oscillation became bothersome during the initial climb and reducing roll SAS (0-7-8) did not adequately alleviate the oscillation. Simulator adequately predicted roll motion.

C. Please comment on effect of longitudinal acceleration in accomplishing climbout.

Pilot Comment: Relaxing head back against headrest possibly resulted in a longitudinal stick movement sufficient to produce a 3.3g pitch oscillation as airplane pushed over to zero g.

D. Adjustment of trim , or stick force , preferred for longitudinal control?

Pilot Comment: With normal SAS, prefer to trim out force. Trim button would provide more positive control over stabilizer trim settings. Simulator representative under these flight conditions.

E. Rate airplane damping in pitch 5 , roll 3 , yaw 1. 5 .

F. Rate side stick control effectiveness in pitch oversensitive, SAS Off, roll poor centering.

G. Rate side stick force gradient in pitch high, roll ? .

Pilot Comment: Pitch to roll force gradient ratio not as compatible as with center stick .

H. Did side stick control motions and forces appear linear low a's , or nonlinear dh > 20° with resulting airplane response ?

I. Was side stick position comfortable in this trim range?

Pilot Comment: No. Back stick required to trim is greater than wrist movement available, necessitating raising forearm to a cramped position.

III. Acceleration at Zero g A. Rate pilot task during acceleration run to Vmax.

Pilot Comment: Speed run was easier to control than climb.

1. Rating No. in pitch 5 , roll 3 , yaw 1. 5 .
B. Pilot's attention was directed principally toward pitch control mode during speed run?

C. Please comment on airplane stability and trim to Vmax.

Pilot Comment: Airplane appeared more stable about all axes.

D. Adjustment of trim , or stick force preferred for longitudinal control during speed run?

Pilot Comment: Trim out all force when using side stick but retain a small force when controlling with center stick.

E. Describe cues used for determination of engine shut-down point.

Pilot Comment: First inertial velocity meter followed by ground control time check. Pre-flight simulator runs were helpful on this item.

F. Was sufficient time available to prepare for engine shutdown without exceeding planned Vmax?

Pilot Comment: Yes -- Pilot had sufficient lead time to prepare for engine shutdown.

G. Vmax was 5,000 ± 50 fps, and out of trim motions (if any) at shutdown were about ? ° in pitch ± ? ° in roll, and ± ? ° in yaw?

Pilot Comment: Engine shutdown out of trim motions were either very small or were masked by the continuous pitch oscillation.

H. Other than the instruments, were any new cues apparent to indicate the airplane is traveling at great speed?

Pilot Comment: Pilot could sense that airplane was radiating heat into cockpit. Increased suit cooling was required.

I. Please describe and rate airplane response to rudder kick and pitch pulse at a = 0°.

Pilot Comment: Low amplitude yaw-roll motions followed rudder step input. Damping was light but positive. Pitch pulse was not attempted.

IV. Pullup to a = 15° A. Rate pilot task required to pullup and trim at a = 15° with SAS at O-6-8

Pilot Comment: SAS settings were 0-4-8.

1. Rating No. in pitch 3 , roll 2 , yaw 1 .

2. Airplane trimmed at a = 12°, 14°, and required maximum stabilizer trim max or stick force above stab. trim limit ?

Pilot Comment: High angle of attack below 4,000 fps required maximum trim plus back stick force. a = 15° was not attempted due to pitch controllability problem. Pilot task would have been difficult even if SAS were operable.

B. Was longitudinal control motion linear , or nonlinear x , with a?

C. Was longitudinal control force linear ? , or nonlinear ? with a?

Pilot Comment: Could not recollect force gradient.

V. Controllability at a = 15° A. Was any reduction in controllability apparent at 8-6-8 SAS gains? If affirmative, describe.

Pilot Comment: Final SAS settings were 0-4-8. Wallowing reported on previous flight, was apparent at these flight conditions also. Airplane appeared neutrally damped in roll at the elevated angle of attack.

B. Pilot's attention was directed principally toward roll control mode during the high a deceleration?

Pilot Comment: Pilot concentrated on keeping wings level during deceleration. Holding high a and damping pitch motion was secondary consideration.

C. Aileron x , or rudder used for directional control? Please comment on airplane response in yaw to aileron inputs.

Pilot Comments: No attempt was made to damp lateral-directional wallowing with rudder. Yaw from aileron input was quite noticeable.

D. Please describe airplane response to aero control pulses,

Pilot Comment: Larger yawing motion developed from aileron pulse than from rudder pulse. Airplane motions indicated slight positive damping from pulse disturbances.

E. Please describe airplane response to BCS control pulses.

Pilot Comment: Pilot was able to discern airplane response to BCS pulses. Angular accelerations were quite low due to marginal flight conditions for BCS operation.

F. Longitudinal trim was held at a = 10° ± 2,3°, and lateral trim could be held ± 30° between pulse maneuvers?

Pilot Comment: Suit inflation interfered with center stick travel and aggravated the longitudinal control problem somewhat. Side stick control was easier during elevated a flight with suit inflated.

G. Did speed brake deployment produce noticeable nose down trim change? · a = °?

Pilot Comment: Speed brakes were not deployed during this flight.

H. Did speed brakes have any apparent effect on response to control inputs?

Pilot Comment: Same as G.

VI. General Questions A. The outstanding deficiency noted during the flight occurred about the pitch axis (or axes) and resulted from:

1. Inadequate stability .

2. Inadequate damping X .

3. Inadequate control effectiveness X side stick

4. Inadequate control force characteristics X side stick

5. SAS X .

6. Cockpit presentation .

7. g effect .

8. Other X .

Pilot Comment: Roll residual during low a, high q flight conditions. Low damping resulting in lateral-directional wallowing flight at a » 12°.

B. Did NASA simulator adequately predict the airplane motions encountered on this flight?

Pilot Comment: Airplane environmental factors increase control problem compared with simulator. Stability deficiencies encountered during the flight were generally predicted by the simulator.


Typed: 6/12/61