X-15 OPERATIONS FLIGHT REPORT



FLIGHT NO: 1-55-89 DATE OF REPORT: 7/8/65

PILOT: M. O. Thompson DATE OF FLIGHT: 6/17/65

CARRIER AIRCRAFT: B-52 #008 LAUNCH LAKE: Delamar

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

PURPOSE OF FLIGHT: 1. I. R. Scanner

2. Honeywell Inertial System Checkout

3. Cross Track Vernier

I. Discussion of Previous Operations

A. SAS continues to exhibit extreme sensitivity to aircraft electrical transients as evidenced by the incident of pitch channel trip-out on the previous flight (1-54-88) prelaunch period and the present flight 1-55-89 where both pitch and roll channels were lost after hydraulic pressure was established. Extraordinary ground checkouts of SAS have not isolated a system deficiency, therefore more extreme action, including SAS rewiring and electrical radiation shielding of sensitive SAS components, will be considered. II. Aircraft Configuration Changes A. The MIT experiment was replaced with the Singer IR Scanner. The light-weight tailcone replaced the beefed-up tailcone including the experiment box. The "C" Band Radar antenna was transferred to the replacement cone.

A configuration change was made to the IR Scanner assembly to attach reflection shielding (polyurethane foam painted flat black) to the window frame and guillotine and to install an enclosure surrounding the scanner lens (covered by EO898939).

B. The ASAS engagement circuit was altered to provide for a pitch SAS channel failure signal in addition to the roll channel signal. Because of the circuit configuration, the change resulted in a yaw malfunction induced ASAS engagement. It was necessary to change the inflight-test procedure to properly check the normal SAS trip-out.

C. General Electric ablation material spray and low density type were applied to the F-3 and F-4 BCS panels.

D. The IFDS electrical power circuitry was changed to eliminate a 28 VDC relay powered by X-15 bus power. This relay caused loss of platform precision power during the period of ground to B-52 alternator power transfer. The altitude-loop updating manual selector was replaced with a continuous pressure altitude transducer to automatically update the IFDS. The transducer is plumbed in parallel with the pilots display static-pressure system.

 III. Preflight Events A. A periodic aircraft x-ray survey was accomplished including the wings, horizontal tail, upper and lower stub ventral structure, and upper vertical. Review of the x-rays yielded negative results. A period of approximately 12 months elapsed since the last x-ray series.

B. The cockpit pressure regulator was replaced because of the 38,000 foot cockpit altitude of the previous flight.

C. The PDM components were removed from the aircraft and operated in the laboratory to check environmental effects. The T/M transmitter was found to be temperature sensitive.

D. The pilots breathing pressure regulator was replaced because of high lockout pressure creep to 105 psig. The pilots low O2 pressure switch was replaced because of an unexplained previous warning indication in flight.

E. The No. 1 APU H202 tank was replaced because of a leak in the Vicone bladder.

F. Inspection of the MLG as part of the 5 landing x-ray requirement indicated significant galling in the MLG flange and mating bellcrank bearing shoulder faces. The patterns of the galled areas indicate drag loads during extension rotation are the cause. No action was taken; however, the surfaces were treated with DGV graphite spray.

G. The MLG bell crank were found to be interchanged left to right and vice versa. The parts were symmetrical except for grease fitting locations affecting ease of access to the fittings.

H. A satisfactory engine run was accomplished with S/N 108 on 6/3/65. A stop-prime shutdown was necessary on the first start because of failure of idle-cooling cutoff caused by an improper harness connection (pushed pin in a plug). The second start resulted in a vibration shutdown caused by a slow bleed-off of idle-cooling gas and a premature call for "throttle on"; the idle-cooling dump valve was not armed. Satisfactory APU runs were accomplished with APU #1 S/N 16 and APU #2 S/N 20.

I. The engine purge gas regulators were replaced because one regulator lockout pressure was above relief pressure.

J. Rescheduling of the flight was required because of delays in X-15-2 efforts on 6/10/65 and the pilot's schedule on 6/15/65.

K. The aircraft was mated to B-52 #008 on 6/16/65.

 IV. Flight Events A. Operation of the SAS during the outbound track before and after hydraulic pressure was marginal because of trip-outs of pitch and roll channels. Resets were made and the decision was made to proceed with launch. The pitch-roll tripped out on launch and ASAS operated satisfactorily until the pilot reengaged normal SAS late in the flight. Trip-out of pitch and roll occurred again in the descent to landing. One reset of SAS was made without ASAS disengagement.

B. The tape data switch was not selected until after launch, however, the tape data configuration was negligible (engine vibration only).
 
 

 Approved by: Prepared by:

Perry V. Row Ronald S. Waite

X-15 Senior Project Engineer X-15 Project Engineer