MEMORANDUM for Chief, Research Division X-15 Project Office

FROM: X-15-3 Research Project Engineer

SUBJECT: Flight Research Report on flight 3-49-73

Flown on September 28, 1965, by John B. McKay

I. PURPOSE OF FLIGHT

To obtain data for the following programs:

The flight was planned for 260,000 feet, and a peak altitude of 294,000 feet was reached. The original flight plan was based on a 58,750 pound thrust engine. This engine was changed and the new thrust figures were available two days before the flight. The new thrust of 61,000 pounds was used on the simulator and it reduced shutdown time from 81 to 79 seconds.

During the flight, the pilot could not reach the throttle in time and an overshoot in velocity occurred. The planned shutdown velocity was 5150 fps and the actual shutdown velocity was 5470 fps.

Postflight research indicated that the engine thrust developed was 61,500 pounds, and the actual pitch angle flown was 39.6° instead of 39°. This profile was duplicated on the simulator with enough accuracy to indicate that the above data were correct.

It was also noted that longitudinal acceleration at shutdown was about 3.9 g's. At a g » 31 ft/sec.2, normal reaction time could contribute up to 30 fps overshoot.

(Remainder of report missing)
 
 

Joseph A. LaPierre

Aerospace Engineer