June 20, 1967

MEMORANDUM for Chief, Research Projects Office

Flight 1-72-125 was flown on June 15, 1967, by Major Michael J. Adams for the purpose of:

The primary flight objectives were attained and acceptable data were obtained on all experiments.

Flight Track and Profile

The radar track and profile for this flight are shown in figure 1.

The launch was at Delamar #2 from 45,080 feet, IAS - 222 Kts, and Mach 0.815. Engine light occurred 1.4 seconds after launch.

The pilot reported starting throttle back at an indicated velocity of 5130 fps. The maximum velocity observed by the pilot was 5190 fps. Preliminary radar data indicates a maximum velocity of 5250 fps at 136,000 feet or 100 fps higher than planned. As a result of the extra 100 fps, the maximum altitude was 7,000 feet higher than planned or 227,000 feet. The pilot reported that the inertial altitude also indicated 227,000 feet at peak. Engine burn time from throttle-on to throttle-off was 81.2 seconds or 0.4 seconds longer than planned.

The ground track was about 2° east of the planned track during the powered portion of the flight. Approximately 25 seconds after launch a right roll of 16° was executed to straighten the ground track; however, the heading was allowed to drift back to the planned heading in the boost phase. This resulted in the actual track being 8 nautical miles to the left of the planned track at entry.

After entry the pilot pushed over to low a and extended speed brakes to 35° and began the planned right turn to high key. Since the ground track was 8 nautical miles to the left of the planned track the vectoring turn required 2.8 g for approximately 40 seconds. High key was entered at Mach 1.0 at 40,000 feet.

Stability and Control

A time history of the significant stability and control parameters telemetered during the flight is shown in figure 2.

At shutdown the pilot felt that he induced a small pitching oscillation (q ±2°) when he reached for the throttle. A minor engine thrust vector misalignment caused a 2° nose left sideslip at shutdown; however, this presented no piloting problems.

There were no other significant stability and control problems.

Weight and Balance

A time history of the total airplane weight is shown in figure 3 and the longitudinal center of gravity position is shown in figure 4.

Air Force Western Test Range Launch Monitoring

This was the second flight of the experiment to provide an operational checkout of the systems operation. Postflight examination of the experiment produced the following discrepancies:

MIT/Apollo Simultaneous Photographic Horizon Scanner

Preliminary analysis indicates that all systems functioned satisfactorily. The experiment has been removed from the aircraft and returned to MIT for re-calibration. The experiment will be re-installed for the June 27 flight.

Horizontal Stabilizer Local Flow Direction

Data were obtained for this experiment. Preliminary review of the data failed to disclose the occurrence of the local flow direction change with BCS operation.

Operational Discrepancies

During the runup the burst disc on the stick kicker was ruptured. The flight continued as planned with special instructions to the pilot to hold the stick forward at touchdown. A relief valve has been installed to replace the burst disc to prevent future problems.

At shutdown a blown fuse in the WTR experiment's frequency converter was attributed to a large voltage transient output from the number one APU. For this flight the power inputs for the WTR experiment came from both APU's. To prevent future problems all inputs are being wired to the number two APU which has lower transients.

Data Systems Discrepancies

The only discrepancy note for this flight was light timing lines on the three axis accelerometer A-8-3M. This discrepancy is being corrected for the June 27 flight.
 
 
 
 

E. J. Adkins, Chief

X-15 Project Office