X-15 OPERATIONS FLIGHT REPORT



FLIGHT NO: 1-61-101 DATE OF REPORT: 11/10/65

PILOT: Capt. J. Engle DATE OF FLIGHT: 10/14/65

CARRIER AIRCRAFT: B-52 #003 LAUNCH LAKE: Delamar

ENGINE SERIAL: 108 APU #1 16 APU #2 20

PURPOSE OF FLIGHT: 1. MIT Horizon Photometer (Phase I)

2. Pace Transducer (LH Pod Nose)

I. Discussion of Previous Operations

A. Evaluation of the main landing uplock roller bracket attachments using Sauerisen ceramic cement and epoxy cement on the bracket interface, indicated relative movement between roller bracket and gear attach flange was occurring. Removal of the 5/32 diameter NAS 1200 rivets showed varying degrees of step shear in the rivet shanks. Oversize elliptical holes and overdone off-center counter sinks prevented a proper rivet installation on the original assembly. The rivets were replaced with duplicate rivet configuration. Tests were conducted on a non-flight strut assembly, indicating a load capability of 1650 lbs ultimate load. A redesign was made based on a strut temperature gradient of 569°F which was not included in the original design. NAA, using most severe gear preload and strain-gage hook loads from X-15-3, will provide an increase in roller bracket rivet size to 1/4 diameter, Inconel-X brackets to replace 4130 brackets, beefed-up hook with over-center geometry and an increase in material strength. The bracket system yield strength is raised to approximate 2770 lb. Close inspection will continue pending reconfiguration to the new design. II. Aircraft Configuration Changes A. The IRATRAN window assembly was replaced with a metal plug since the IR Scanner experiment was concluded.

B. The MIT Horizon Scanner, Phase I with tailcone box were installed as the prime experiment.

C. The air density Pace transducer was installed in the LH wing pod nose cone.

 III. Preflight Events A. Epoxy cement was again applied to the main landing gear uplock hook brackets after rivet replacement, reference Item I A.

B. APU runs accomplished on 10/2/65 were satisfactory. A RAS leak check indicated leakage from the pitch up rocket motor however, cycling the valve eliminated a major portion of the leakage. This valve caused the flight abort (l-A-100). The RAS valve could not be operated in the airborne configuration as it is on the ground. An in-flight RAS test switch is proposed to allow airborne valve operation.

C. An extended closed canopy cockpit and regulator purge was accomplished the day before flight l-A-100.

D. Flight l-A-100 was accomplished on 10/8/65, intended as a flight demonstration for the X-15 conference. Capt. J. Engle was pilot and the aircraft was mated to B-52 #003. The abort was caused by excessive leakage from the RAS pitch up rocket. A spurious IFDS malfunction detector signal was obtained on the first attempt to operate the IFDS on the ground before flight; the indicated computer gross malfunction did not represent actual system operation and was accepted for flight. Restart of the system eliminated the indicator malfunction. The abort flight data was removed from the two oscillographs and the tape recorder in order to evaluate the MIT temperature environment. Adjustments were made in the MIT experiment compartment temperature sensors to raise the temperature level as result of the data evaluation.

E. The RAS pitch-yaw valve was replaced after l-A-100. Engine preflight functionals and IFDS computer reload was accomplished Monday, 10/11/65.

F. The flight was canceled after pilot entry on 10/13/65 because of weather.

 IV. Flight Events A. The flight was scheduled for 1100 because of a B-70 flight. The lateness of the launch and sun angle produced serious reflections on the instrument panel from the pilot's silver suit, and required the pilot to look directly into the sun. The pilot stated that the conditions hampered proper profile control.

B. The cabin helium source pressure leakage was excessive with launch accomplished at 2250 psig; 900 psig remained after landing.

C. The SAS yaw channel disengaged at launch and was reset by the pilot. The yaw again disengaged during reentry when severe yaw oscillations were encountered. Reset could not be accomplished until the oscillations were damped out.

D. Consumption of APU H202 was sufficient to require use of the H2O2 transfer system.
 
 
 
 

 Approved by: Prepared by:

Perry V. Row Ronald S. Waite

X-15 Senior Project Engineer X-15 Project Engineer