B. An altitude predictor was installed in the cockpit to give the pilot a continuous prediction of the maximum altitude attainable at engine shutdown.

B. The #1 and #2 shutoff valves were leaking and necessitated changing.

C. Cabin leakage has increased to 70.5 cfm at 3.5 psig, from previous operation. It was felt that this would be satisfactory for flight.

D. A flight (3-A-33) was aborted on 8/6/63 due to unfavorable weather conditions up-range.

E. During checkout of the altitude predictor on 8/9/63, a fuse was blown in the stable platform computer. This required removal of the elevator in the mated condition.

F. Because of adverse weather conditions, the preflight functionals were re-run. During the propellant checks the lox tank regulator would creep up slowly to almost relief pressure. This required demating to install a new regulator. The propellant functional was then completed without any discrepancy.

G. Flight 3-A-34 was aborted on 8/l3/63 due to the inability to keep the #l APU running. The APU would start and then shutdown in approximately 4 seconds. This type of malfunction looked like one which had occurred previously when the latching mechanism on the APU shutoff valve failed. This valve was replaced. The removed valve was checked in the lab and no discrepancies were found in its operation. Also the APU operated satisfactorily and no problems were observed.

H. During ground checks for the APU, the #2 cooling blower became inoperative. This required removing the elevator to change.

I. The generator-out-light circuit developed an open wire and this was replaced while the elevator was out for the blower change.

J. During checkout of the stable platform system, after reinstalling the elevator, excessive fluctuations of the altitude predictor and altitude indicator were observed. The elevator was again removed and after two computer changes, it was again reinstalled.

K. On 8/15/63, flight 3-A-35 was aborted due to adverse weather conditions. During the return flight, several attempts were made to start the #l APU but it would not run over approximately 4 seconds. Ground checks re-vealed that the APU controller was affected by low temperatures and that it would cause an over-speed shutdown below 0°F. This was the first experience of this kind on the controllers.

L. Also during this mated flight the radio was inoperative. .The radio was changed. During bench check-out of removed radio, it was found that the power supply plug did not have full engagement of its pins.

M. The airplane was demated to rerun all the functionals and rerun the engine.

N. The H2O2 engine safety valve was replaced prior to engine run because of leakage observed during the aborted flights.

O. The engine lube pump was replaced due to excessive seal leakage.

P. #1 APU was changed due to excessive oil leakage from the gear case.

Q. A successful engine run was performed on 8/19/63.

R. The #2 engine spark plug was inoperative after the engine run. Replacing the exciter resulted in satisfactory operation.
 

B. The left roll BCS rocket, actuated by the MH automatic reaction control valve, would not operate. It is believed that the H202 froze in the lines to the rockets. It is suggested that the pilots do a longer BCS check to warm up these lines.