B. Modifications of the mixing chamber pneumatic control gas system per ECP X-15-155 has resulted in intermittent regulation of mixing chamber temperatures. After extended periods of operation, higher than normal mixing chamber temperatures are obtained. As described in previous reports, the tubing coil placed at the blower inlet to provide higher control gas temperature as a corrective measure improved the operation, however, heating capacity is marginal.

C. Pilot suit vent capacity is also marginal when the pilot selects more than two turns on the control valve and the high setting on the heater. The heater capacity had been increased by adding a resistance winding on the fin-tube heat exchanger. Added heater capacity or reduced pilot vent requirements will be required to prevent expelling extremely cold gas or liquid LN2 into the pilots suit.

B. The inertial platform computer malfunctioned and was replaced during the post-mate checks.

C. A flight attempt was made on July 2, 1963. A foreign material resembling asbestos insulation lodged in a pylon LN2 supply shutoff valve and also in the pylon LN2 disconnect fitting resulting in the loss of pilot suit vent and the heat and vent liquid nitrogen supply. The fuel single point disconnect was replaced because of leakage in the course of aircraft servicing and the lox tank regulator malfunctioned in a manner which vented the fox source overboard following the venting operation of the ground jettison check. The regulation function of the lox tank regulator was not affected and replacement was not required (the X-15 must be demated to replace the lox tank regulator).

D. Flight 1-A-58 was attempted on July 3, 1963. The flight was canceled by inoperative X-15 communications. Bench checks accomplished after the flight revealed a faulty transmit-receive relay with improper contact action.

E. An intermittent No. 2 generator-out light was traced to the generator control relay contacts. The upper elevator was removed to allow replacement of the No. 2 generator control relay. During the flight servicing, a short APU run was accomplished with generators on the line to demonstrate the system.

B. The No. 1 APU H2O2 low light flickered during operation of the RAS. This light condition did not indicate a capacity condition, however, it does imply that the rapid RAS valve opening is causing a pressure differential between the tank standpipe and regulated helium source sufficient to operate the pressure switch. RAS operation was not affected.

C. The 13 cps oscillation of the horizontal surfaces was detected by the RAS electronics and RAS inputs occurred intermittently at this frequency from ten seconds beyond burnout until the system disengaged at auto-cutoff during reentry.

D. The traversing probe became inoperative after burnout due to an overloaded fuse. The fuse supplied the 3 axis accelerometer and the main chamber 3 channel pressure recorder in addition to the traversing probe. The fuse capacity has been increased.