Flight 3-24-41 was flown by Milton 0. Thompson on November 27, 1963, for the purpose of pilot checkout. Energy management information was not available to the pilot due to a blown chopper excitation fuse in the computer associated with the inertial platform. Other systems appear to have functioned normally throughout the flight.

The launch configuration for this flight was MH-96 adaptive, R.C. off, BCS off, Heading vernier to standby, and lower ventral off. The launch was made in the vicinity of Hidden Hills on a magnetic heading of 212° at an altitude and a velocity of approximately 44,000 feet and 740 feet per second respectively. The maximum altitude and velocity attained during the flight was approximately 89,O00 feet and 4800 feet per second. The maximum dynamic pressure was approximately 1300 psf.

The powered flight duration was 89.6 seconds with engine light occurring 2.1 seconds after launch. The throttle was moved past the 75% throttle gate and 10.1 seconds of flight occurred at approximately 90% thrust. The pilot reduced the thrust to approximately 60% using the chamber pressure gauges for reference. Glare from the sun interfered with the pilot's vision and angle of attack increased to approximately 18.1 degrees at 2.2 seconds after launch. Intermittent buffet occurred for 3.2 seconds as angle of attack decreased to 12.3 degrees and reoccurred when the angle of attack increased to approximately 17.0 degrees. The pilot reduced the angle of attack to approximately 7.7 degrees, maintaining a » 8° ± 3° during rotation. Approximately 4.1 seconds after launch, the pilot performed a - da input (fmax »-14.7°) and returned to f » O degrees after 2.1 seconds.

The pilot pushed over at 39.8 seconds after launch, at q » 34.9°, a » 9.1°, and An » +2.1 "g." The aircraft rotated to q » 20°, a » -2.6°, and An » -0.7 "g", after 8.7 seconds and was then rotated till q » 26° and An » 0.85 "g", with a gradual decrease in pitch attitude until shutdown, when q » 5 . 4 ° and An » +0.75 "g".

Shortly before burnout, a moderately severe transient was noted in the servo follow-up, surface positions, and related parameters. This transient was not electrical, but may have been caused by structural thermal relief. Visual inspection of the aircraft disclosed a severe buckle in the side fairing in the vicinity of the servo-actuator installation that could have affected the servo-actuator linkages to produce the transient. A similar occurrence can be expected on future flights where structural yielding to thermal stresses are expected.

The pilot indicated that he flew "g" during pushover, rather than angle of attack and rated the control task for the speed run as:

q 2 , f 2 , y 2.5 .

Following shutdown, the pilot performed a da input (q » 780 psf, fmax » -44.2°) and a series of rudder pulses with the MH-96 system on adaptive. The pilot switched the yaw damper to fixed gain and performed a series of rudder inputs (^·b » 2.8°, ^·y » 7.2° ) and a +da input (fmax » +40.8). The pilot extended the speed brakes slightly (dj » 5°, q » 800) and performed a +da input (fmax » +48.6°) after which the speed brakes were extended to 20 degrees (q » 1100 ) and the yaw damper was switched to the adaptive setting. The speed brakes were fully extended (q » 1200 psf) and the pilot performed a -da input (fmax » -79.1°) followed by a -dv pulse. During the roll maneuvers, the pilot was not aware of any limit cycle and did not notice any heading change. Damping was considered to be very good and the pilot ratings were:

q 2 , f 2 , y 3 .

The pilot then closed the speed brakes for 25.8 seconds as the vehicle approached high key. The maximum angle of attack (a » 19.9°) during this flight occurred during the turn with f » -69°. The pilot extended the speed brakes in intervals and buffet occurred at a » 10.0°, q » 240 psf, M » .95, and intermittently throughout the remainder of the flight.

Out of the turn, on final approach, the pilot closed the speed brakes for 13.1 seconds followed by intermittent opening and closing of speed brakes. During this interval, the normal acceleration momentarily reached 4.0 "g". Immediately prior to touchdown, the pilot opened the speed brakes full and angle of attack increased to 17.9 degrees at touchdown. The touchdown was at a rate of sink of approximately 6.4 feet per second and occurred approximately l300 feet south of the 2-mile marker.

Nose-gear touchdown was approximately 205 feet from main-gear touchdown. The landing disengage switch was utilized during the landing and the servos were centered and locked approximately .l seconds after main-gear touchdown, completing 423.6 seconds (7.06 minutes) of flight time.
 
 
 
 

James R. Welsh

Aerospace Engineer