Flight 3-64-95 was flown on October 17, 1967, by Major William J. Knight for the purpose of obtaining data for:

Acceptable data were obtained on all experiments except the Pod Deflection experiment. Loss of data for this experiment was caused by a coating of hydraulic fluid getting on the scanner lens.

There were no major malfunctions during this flight.

Flight Track and Profile

The radar track and profile for this flight are shown in figure 1. The ground track showed launch approximately 0.5 nautical miles west of the planned launch point. Due to a 3.5° discrepancy shown between the actual and the planned ground track this distance had increased to about 4 nautical miles east of track near Ballarat Lake where a right turn was initiated to Edwards. The pilot's display indicated the planned heading was being flown throughout the flight. This discrepancy has been noted on several flights from Smith Ranch Lake and is being investigated in an effort to determine its cause. In an effort to compensate for this discrepancy the aircraft was launched on a heading 2 degrees to the right of the planned track. This 2° correction reduced the deviation between planned and actual ground tracks by approximately one-half that of the previous flight.

The flight profile, as shown in figure 1, is approximately 4000 feet higher than planned. The planned profile was established without the aid of boost guidance. When boost guidance was incorporated into the simulator for pilot training purposes the profile consistently came out essentially the same as the flight profile.
 
 

Stability and Control

A time history of the significant stability and control parameters telemetered during the flight is shown in figure 2. The launch, from Smith Ranch Lake on a heading of 170 degrees was normal.

Engine burnout occurred after 84.2 seconds of powered time giving the planned final velocity of 5600 fps. During the ballistic portion of the flight to peak altitude roll maneuvers were performed to obtain data for the Ultraviolet Exhaust Plume Measurement experiment. Other experiments were activated as the required altitude was attained.

During the descent from peak altitude the pilot held 24 to 25 degrees angle of attack while setting up for reentry. The reentry was performed at 5g and 22° angle of attack as planned. The normal acceleration, as shown in figure 2, is incorrect for the reentry maneuver since the linear range of the accelerometer was exceeded.

The glide back to Edwards was performed as planned. Buffet was experienced during the landing pattern at approximately 6 to 7 degrees angle of attack and a Mach number of 1. The approach, landing, and rollout were normal.

A time history of the airplane weight is shown in figure 3, and of the longitudinal center-of-gravity position is shown in figure 4. The calculated landing weight was 14,905 pounds with a longitudinal center-of-gravity position of 24.1 percent of the mean aerodynamic chord.

Ultraviolet Exhaust Plume Characteristics

Partial data were obtained on this experiment. The dual channel radiometer functioned properly; however, the camera did not operate. A malfunction of the camera heater during taxi was the cause of camera failure. Postflight examination revealed that the heater problem was in its wiring.

The dual channel radiometer data has been sent to the experimenter for a detailed analysis.

Solar Spectrum Measurement

The Solar Spectrum experiment was activated during the flight by the pilot, at an altitude of approximately 180,000 feet.

The experiment functioned as expected, acquiring and tracking the sun for approximately 150 seconds, until it was turned off as the airplane descended through 190,000 feet.

A preliminary analysis of flight data, by the experimenter, showed no discrepancies. A detailed analysis of the data is in progress.

Micrometeorite Collection

This experiment was activated during the flight by the pilot at an altitude of approximately 180,000 feet. The experiment extended and proceeded through its automatic timing cycles as planned. Because of problems experienced on the previous flight during the retract operation, the experiment was retracted as the airplane descended through 190,000 feet instead of 180,000 ft.

A postflight inspection of the experiment revealed it functioned normally; except, only four of the six collector surfaces had been exposed for their 16 second period. The pod has been removed and sent to the contractor for investigation into the cause of this problem. The collector package and flight data have been returned to the experimenter for a detailed analysis.

Ames Boost Guidance

The Ames Research Center's Boost Guidance experiment was programmed in the ALERT computer for this flight. The pilot was to fly the boost portion of this flight using boost guidance as long as the display of pitch attitude was within +2° of the planned 37°. The experiment functioned as expected.

The flight data have been sent to the Ames Research Center for a detailed analysis.

Pod Deflection Scanner

No acceptable data were obtained on this experiment due to a coating of hydraulic fluid on the scanner lens. The hydraulic reservoir was not serviced to a one-half inch lower level for this flight as planned. In an effort to alleviate this problem the reservoir will be serviced to the lower level for future flights.

Data Systems Discrepancies

The following discrepancies were noted on PCM prime commutator:

Ch. 35 Nose gear S/G 408 was intermittent during flight.

The following discrepancies were noted on PCM sub-commutator:

#1 Ch. 1-45 Left-hand bell crank was not operating properly.

Ch. 1-68 UV-l Static was improperly plumbed.

#2 Ch. 2-24 #1 nozzle box pressure froze up during flight.

The following discrepancies were noted on the Parsons tape:

Ch. 6 The fin tip acceleration tape track was faulty.

Postflight examination revealed the 16 mm camera and camera heater for the ultraviolet plume experiment did not operate during the flight. A preliminary analysis of the onboard data showed that the Gulton timer reset prior to launch.

These problem areas are being investigated to determine their causes and the steps necessary to correct them.

Operational Discrepancies

Inspection of the airplane on the lakebed showed the third skid did not deploy. Further investigation revealed the failure to deploy was because it was not armed.
 
 

E. J. Adkins, Chief

X-15 Research Project Office