X-15 OPERATIONS FLIGHT REPORT

FLIGHT NO: 2-51-92 DATE OF REPORT: May 23, 1967

PILOT: Maj. W. Knight DATE OF FLIGHT: May 8, 1967

CARRIER AIRCRAFT: B-52 #008 LAUNCH LAKE: Hidden Hills

ENGINE: S/N 109 APU #1 21 AN APU #2 22AN

PURPOSE OF FLIGHT: (1) Stability and Control with Dummy Ramjet

(2) Canopy Eyelid Checkout

(3) T/C System Checkout

(4) Ramjet Local Flow Data

(5) Alternate Airspeed Source Evaluation

I. Discussion of Previous Operations

A. Failure of the T/C recording instruments to survive the severe environment in the "29 bay" next to the Lox tank on the last several flights resulted in the decision to install an electric heater system and make a captive flight to check its effect. Accordingly Flight 2-C-90 was made on December 22, 1966, with this item as its primary objective.

Reliable recording of the T/C's was not obtained, and it was then decided to move the entire T/C package to the environmentally controlled instrument bay. (Space for this relocation was available since the Startracker experiment has been terminated,)

II. Configuration Changes A. Relocation of the T/C recording instruments to the instrument bay.

B. Nose gear "thin" door installation.

C. L/H windshield eyelid installation.

D. Yaw ASAS installation.

E. Installation of an instrumented dummy Ramjet and associated ventral stub "pylon" modification.

F. Removal of BCS rockets and valves to save weight.

G. Removal of Startracker experiment and deactivation of "flip-top" doors.

H. A screen was installed over each transformer/rectifier case opening to keep stray hardware from causing short circuits.

I. Installation of ARC-51 radio.

III. Preflight Events A. On December 16, 1966, the decision to terminate the Startracker experiment was made.

B. A captive flight (2-C-90) was made on December 22, 1966, to check the operation of the T/C heater modification under the severe chilled environment of captive flight, (see Section I-A). Secondary objectives were:

1. Functional test of the "thin" nose gear door.

2. Checkout of an alternate procedure for ground erection of the inertial system (inertial mode throughout the flight.)

3. Functional check of the "TAZ 8" ball nose.

All objectives were achieved.

C. The X-15 was placed in work status following the captive flight. The modifications made during this time are listed in Section II.

D. During the week of January 30, 1967, the X-15 was used in a demonstration of ablative particle contamination control by the Martin Company, using the newly constructed ablative spray facility at FRC. The demonstration was successful.

E. In Mid-March, the first dummy Ramjet was received from NAA. Installation of instrumentation was begun. This was followed by fit checks and a resonant vibration test with the Ramjet installed on the X-15.

F. Preflights were without incident. Engine and APU ground runs were completed on April 27, 1967.

G. The first attempt at Flight 2-51-91 was canceled on 5/1/67 due to unavailability of the C-130 support aircraft, and the X-15 was demated to permit the B-52 to be used for an M-2 flight. The M-2 flight was made on Tuesday, 5/2 and the X-15 remated that same evening. An incorrectly grounded Yaw servo caused Yaw SAS channel failures on two successive days (5/3 and 5/4).

H. Adverse weather caused a pre-launch abort (2-A-91) on Friday, 5/5/67.

IV. Flight Events A. The flight was made on Monday, 5/8. Servicing was normal and X-15 systems operation was generally good. Ramjet separation was very good, but the cable for the Ramjet parachute broke under opening shock loads and the parachute separated. However, damage to the Ramjet was not too serious and it will be repaired. A stronger cable system will be incorporated.

The inertial velocity meter indicated low throughout the flight. A computer error is suspected.

ARC-51 radio reception by the X-15 pilot was intermittent at times. Some trouble-shooting is necessary in this system.

Approved By: Prepared by:

Perry V. Row William P. Albrecht

X-15 Senior Project Engineer X-15 Project Engineer