FLIGHT NO: 1-63-104 DATE OF REPORT: 5/20/66
PILOT: John B. McKay DATE OF FLIGHT: 5/6/66
CARRIER AIRCRAFT: B-52 #003 LAUNCH LAKE: Delamar
ENGINE SERIAL: 103 APU #1 16AN APU #2 20AN
PURPOSE OF FLIGHT: 1. Atmospheric Density (Univ. of
Michigan)
2. Micrometeorite Collector (ACRL)3. Apollo Horizon Scanner Phase II (MIT)
4. Sky Brightness (Nortronics)
5. Stick Pusher
6. Non Glare Glass (a indicator)
I. Discussion of Previous Operations
The experiment configuration includes an electric clutch brake and a gear train with high mechanical advantage which prevents the experiment from extending with power off. Inspection after flight 1-63-104 revealed a sheared gear shaft which allowed the negative "g" forces to extract the mechanism. For the past flight, procedures called for the experiment switch to be positioned at "OFF"; on future flights the switch will be placed in "RETRACT" to provide continuous power if the experiment moves to a position which actuates the closed limit switch. In addition to procedure changes, a beef-up of the failed gear shaft was incorporated and an adjustment of the retract micro-switch was made to insure that the mechanism was not contacting the mechanical limits and loading the gear train.
B. Because of the recent, numerous cockpit pressure failures which have been traced to cold environment of the cockpit pressure regulator, a study was made to select another location for the regulator. A layout was made for installation in the LH onboard rear corner of the elevator bay with the exhaust air ducted through the space between inner and outer skin and into the side fairing. A hole pattern was selected to provide an adequate exhaust path from the inner skin duct into the outer fairing area. The relocation proved satisfactory in operation as demonstrated on this flight with the extended cold soak experienced and the use of external air-conditioning air for the IFDS which, in the past, has caused malfunction of the cockpit pressure regulator.
2. The wing pod experiment installation included:
b. Skybrightness in the LH rear position.
c. The Air Density (University of Michigan) in the RH forward position.
d. Pod cone with ballast (22 lbs total) in the RH rear position.
3. The MLG uplock hook, roller bracket and bracket fasteners were changed by NAA E.0. and provided increased strength; thermal differentials causing bowing of the MLG strut have caused higher loads in the MLG uplock assembly.
4. The stick-pusher system was completed and an operational check was satisfactory to qualify for inflight use.
2. A second digital converter box was installed in tandem with the IFDS display unit to provide the predicted altitude pilots display. The installation is located behind the pilots panel on bracket mounted to the landing gear pulley bracket.
3. The cockpit pressure regulator was relocated from the Sta. 200 bulkhead to the LH rear corner of the elevator bay with an air exhaust duct mounted to the inner skin; air discharge is accomplished between the inner and outer skin and into the side fairing area. Installation was made per ED-0-479 (sheet 1-5).
4. A switch to provide pilot control of the Pitch, Yaw and Roll RAS Solenoid Valves was installed. Leakage has occurred after APU H202 pressurization, and cycling of the valve can correct valve seat leakage.
5. The resistance type mixing chamber temperature indicator was installed because of shortages of the Hickok Gages.
6. The engine 501 power relay was removed from the engine D.C. circuit; D.C. power is now controlled directly with the master switch.
7. The aircraft electrical circuit secondary bus was installed to automatically reduce electrical load with loss of one generator. The RH windshield heater and one air-conditioning blower are powered by the secondary bus.
2. An added IFDS computer protection circuit was incorporated into the electrical configuration which signals the computer dump circuit when either alternator drops from the line.
3. The IFDS loader harness connectors were relocated from the elevator compartment to the cockpit LH rear console to allow IFDS reloading and trouble shooting without removal of the elevator lid.
2. The wing pod disconnects were installed per EO808970, 971, 972 in order to provide configuration flexibility and to avoid necessity of the rewiring effort to remove and reinstall pods.
3. The forward fuselage beef-up for increased landing loads was accomplished per EO898992 (ECP X-15-218).
4. As part of increased landing gross weight capability, the aluminum nose wheels and 10 ply tires serviced to 295 psi were incorporated per EO900567.
5. The IFDS computer environmental air recirculation plate previously attached to the lower elevator frame was moved to the computer shelf structure. The plate produces an air recirculation condition between the exhaust and inlet blowers to avoid over-cooling the computer.
2. A reconfigured pilots display panel and a revised pedestal switch panel were installed. (Fabricated per Sk EE-0-468, sheet 1, 2).
3. The fasteners at Sta. 200 on the lower 90° quadrant between longerons were changed to 7S36J-3A screws to increase shear strength. Portions of the inner elevator floor were removed for access.
4. A closeout plate was designed and installed to replace the heavy upper elevator. Approximately 50 lbs were saved on the installation. Fabrication was accomplished per WO 670-0-4548.
5. The a indicator was shortened by approximately (1) inch to clear an interference and to allow the conventional arrangement of the "G", a , and 3 axis ball indicator locations. The original instrument length interfered with the altitude predictor digital converter box after installation of the new pilots panel.
2. Both APU/BCS ON-OFF-JETT valves were replaced for a slow, incomplete cycle on one valve, and for leakage through the jettison port of the second valve. One stock valve was rejected for external helium leakage at a banjo fitting during the post installation checkout.
3. The cabin pressure regulator was replaced because of an off-schedule regulation of 38K of the previous flight.
4. The Lox vent
valve was noted to have a crack in the valve seat. The stock item had a
score mark across the sealing face of the adapter body requiring exchange
of details with the old valve.
C. A series of flight date rescheduling was required by periodic rain and wet lake conditions. The various schedule target dates were 11/30/65, 12/14/65, 1/5/66, 3/1/66, and finally 4/12/66. Each reschedule period was occupied with configuration changes, some of which apply to future experiments.
D. Time compliance items and maintenance were accomplished and included:
2. An on-board pressure transducer calibration was accomplished on 3/31/66.
3. An elevator bay area resealing effort was made to rejuvenate deteriorated sealing.
4. A 360 day ejection
seat inspection and operation check was accomplished.
F. A successful engine run was accomplished on 4/6/66 with engine S/N 103. The manifold and discharge pressures were reversed at the engine patch panel. APU runs were satisfactory with a BCS demonstration included. An LN2 crocker valve was replaced because of failure to close in APU-Cooling-Single condition.
G. Pilot dissatisfaction with the new pilots instrument panel layout required relocation of the "G", "Q", and a indicator positions; the revision restored the original relative positions for best cross-correlation of gages during flight.
H. A cockpit pressure check on 4/8/66 produced a leakage rate of 85 CFM. Additional effort reduced the leakage to 81 CFM for flight.
I. Engine preflight functionals were accomplished on 4/18/66. The aircraft was ready for flight, however, X-15-2 was scheduled ahead of X-15-1. An aircraft basic weight was made at 14,288 lbs (minus any propellants and pilot).
J. The aircraft mating was delayed from 4/20/66 through 4/22/66 because of C-130 shortage.
K. Engine functionals were repeated on 4/25/66, however, the flight was rescheduled for 4/29/66 because of C-130 support and X-15-2 priority. All aircraft functionals were reaccomplished including a 30 day ejection seat inspection. The No. 1 air conditioning blower failed and was replaced. Normal APU runs were made on 4/27/66. Further delays in C-130 support allowed time for installation of the cockpit window shade, P/N 240-531286 intended to reduce the effects of afternoon sun glare in the cockpit.
L. Flight was rescheduled for 5/6/66 because of delays in X-15-2 and C-130 support.
M. On 5/5/66, the fourth in an extended series of engine preflight functionals revealed an intermittent S-9 chamber pressure switch in the engine control box. The control box was replaced and a satisfactory engine operation was accomplished. Post engine run functionals and aircraft closeout were completed by 0400 A.M. on 5/6/66.
N. Aircraft service
was accomplished with some attending difficulties:
2. At the request
of high range, the PDM system was turned off during the flight service
preparations to investigate frequency interferences. The commutator fuse
was blown when the system was turned on; however, the T/M master switch
was used instead of sequencing the commutator and master switch. The fuse
was replaced with a 1 amp slow blow variety fuse.
B. The engine automatically shut down at 31.6 seconds because of a low fuel discharge pressure condition; the pilot noted a low fuel line low pressure warning light. A turn back to Delamar was accomplished and jettison of propellants initiated. Final jettisoning occurred under favorable conditions with an aircraft angle of -9° (nose down) resulting in an estimated landing weight of 15,000 lbs. Other touchdown conditions were good, producing "light" landing loads of approximately 7500 pounds skid load. These loads correlate with bell crank loads of 31,073 lbs on the left side and 38,652 lbs on the right side; load limits are 48,800 lbs with an ultimate capability of 73,320 lbs. The touchdown point was long, and the aircraft ran off the lake for 265 feet. The slide out distance was 6397 feet with 6132 feet on the lake surface. The canopy was jettisoned by the pilot before the aircraft left the lake. Moderate damage was sustained by the canopy on contact with the lake surface. The aircraft velocity at the lake edge was 70-80 knots and the elapsed time for final off-the-lake deceleration was 5.8 seconds. Peak bell crank loads were experienced on a bump on the lake edge at 39,678 lbs left and 53,147 lbs right.
C. The aircraft was inspected on site and appeared to have sustained no serious landing gear or structural damage. The right hand fairing door was missing (having been blown off because of engine compartment pressure measured at 3 psig). A crack was noted in the engine fuel pump outlet scroll to explain the abrupt loss of fuel pressure. The B-52 pylon LN2 disconnect and three feet of hard line remained attached to the X-15, probably because of frozen moisture (since the LN2 disconnect was removed with normal effort). A secondary malfunction of the LN2 supply check valve was evident because the LN2 supply was depleted during landing or shortly afterward. Verification of suit vent supply and normal APU bearing temperatures after landing indicate no other problems were caused by the LN2 depletion.
D. The Micrometeorite experiment extended at some time during flight or during the decelerations after touchdown. The experiment switch was not moved from the "OFF" position, reference item I A.
E. The untested
items which demonstrated satisfactory operation during the flight include:
2. The flip-top elevator lid and closeout seal were in good condition, and cockpit pressure was normal.
3. The stick-kicker operated with reduced effectiveness, estimated at 5° up horizontal stabilizer. Some doubt exists concerning magnitude of the stick-kicker input because of opposing pilot inputs. The 600 psi service pressure was reduced by cold soak to 500 psi during the flight.
4. The new pilots panel layout was given approval and pilots comments were not unfavorable.
5. The "window shade" apparently helped with the sun glare problem during the rotation and the landing. The pilot did not retract the shade for landing.
6. The cockpit pressure regulation was excellent with good recovery response shown during the suit check. An exceptionally severe cold soak was demonstrated during the extended takeoff schedule with propellants serviced for 5:25 hours before takeoff.
7. For future reference, the on-board fuel hold time was 4:38 hours; the fuel temperature change recorded was from -49°F to -35°F at launch.
8. The Air Density
experiment containing a radioactive isotope, tritium, was installed for
this flight. Activities on the lake and during the recovery operation were
without incident. The experiment total pressure port was covered with tape
by the instrumentation technician after he arrived at the site. No further
changes were made until the aircraft returned to the NASA hangar. During
the aircraft inspections, the Air Density experiment was removed from the
pod without the tape covering the sensing port. Dirt particles which had
entered the experiment cavity during the landing over-run apparently eroded
the radio-active material from the treated chamber. These dirt particles
were dumped out of the experiment when the experiment was removed. When
a potential problem was later defined, a post-contamination check failed
to locate any residual contamination.
Perry V. Row Ronald S. Waite
X-15 Senior Project Engineer X-15 Project Engineer