X-15 OPERATIONS FLIGHT REPORT

FLIGHT NO: 3-10-19 DATE OF REPORT: October 11, 1962

PILOT: Maj. Rushworth DATE OF FLIGHT: October 4, 1962

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

PURPOSE OF FLIGHT: Investigation of Ventral Off Stability

I. Discussion of Previous Operations

None. II. Aircraft Configuration Changes A. The lower ventral heat shield was installed to allow for ventral off flight.

B. The tail cone was partially reworked at North American to allow for the installation of the ultraviolet exhaust-plume observation experiment. Additional work must be done when parts are available.

C. The MH adaptive flight control system has been changed to be consistent with the airplane for a lower ventral off flight. The changes consisted of removing the yaw rate-to-roll-axis interconnect and the lateral-acceleration loop in the yaw axis.

D. The lower ventral was not installed for this flight.

 III. Instrument Configuration Changes A. FM/FM TM system installed.

B. Angle of attack position indicator CPT installed for correlation with angle-of-attack data and servo recorder data.

C. Two thermocouples were attached to the radar beacon for temperature monitoring.

D. Wiring for the lower ventral GSAP camera sync circuit was completed.

E. A pressure transducer was installed on the #2 hydraulic pump discharge to obtain data on pump pressure delay on APU start.

F. Installation of inertial stabilizer internal temperature probe for readout during flight was completed.

 IV. Preflight Events A. Engine Removal: Engine S/N 107 was removed and sent to PSTS for changing of LOX Safe used throughout the engine LOX system. Engine S/N 107 was disassembled, cleaned, and reassembled using LOX Safe known to have passed recent impact sensitivity tests.

B. APU Removal: The #l system hydraulic pump seal failed during hangar checks. APU S/N 26AN was replaced by APU S/N 21AN.

C. FM/FM Radio Interference: During ground checkouts an interference between the FM/FM TM and the radio guard receiver was noted. However, when X-15 was airborne the interference disappeared.

The interference was analyzed as follows: On the ground due to ground reflected waves or some other phenomenon, a sufficient amount of signal from the FM/FM TM transmitter was able to pass through the tuned RF stage of the guard receiver even though the stage is designed to reject all frequencies except the guard frequency. Having entered the guard receiver, the FM/FM TM carrier frequency beat with the guard receiver local oscillator frequency. The resulting frequency produced by the difference of the two beating frequencies fell within the band width of the second IF stages of the guard receiver. Here they were amplified, passed on to the detector and appeared as noise in the guard receiver output. A fix for this ground noise condition is presently being worked on.

 V. Flight Events A. APU Failure: During the flight APU S/N 21AN which was installed in the #1 system during preflight, experienced an alternator dropout followed shortly by complete hydraulic pressure loss. Removal and teardown of the unit disclosed complete failure of the main drive pinion gear. Initial analysis performed locally by AFFTC is not conclusive but indicates hot gear operation due to interference with alternator drive gear. The interference was probably caused either by slightly loose bearing housings or a dimensionally imperfect pinion gear. Further analysis and final determination will be made by the contractor at Lynn, Massachusetts.

B. Cabin Source Pressure Drop: During flight a partial drop in cabin source pressure was experienced. Check out of the system after flight revealed a sticky relief valve as a cause of this pressure loss.
 
 
 
 

 Approved By: Prepared by:

Perry V. Row John G. McTigue

X-15 Senior Project Engineer X-15 Project Engineer