DAWN OF THE SR-71 BLACKBIRD – PROJECT SENIOR CROWN II

Bill Weaver climbs into an SR-71 at Palmdale.

The NASA SR-71B Blackbird in flight over the Sierra Nevada in 1994.

During the course of the A-12 program, the Air Force had been exceedingly helpful to the CIA. It provided financial support, conducted the refueling program, provided operational facilities at Kadena, and airlifted A-12 personnel and supplies to Kadena for operations over Vietnam and North Korea. Through it all, the Air Force remained frustrated that a strategic reconnaissance mission had been given to another government agency.

On July 24, 1964, at 3:30 p. m., president Lyndon Johnson held a news conference at the State Department Auditorium revealing to the world the existence of Lockheed’s Mach 3-capable reconnaissance aircraft:

Good afternoon, ladies and gentlemen. I would like to announce the successful development of a major new strategic aircraft system, which will be employed by the Strategic Air Command. This system employs the new SR-71 aircraft and provides long-range, advanced strategic reconnaissance plane for military use, capable of worldwide reconnaissance for military operations.

The Joint Chiefs of Staff, when reviewing the RS-70, emphasized the importance of the strategic reconnaissance mission. The SR-71 aircraft reconnaissance system is the most advanced in the world. The aircraft will fly at more than three times the speed of sound. It will operate at altitudes in excess of eighty thousand feet. It will use the most advanced observation equipment of all kinds in the world. The aircraft will provide the strategic forces of the United States with an outstanding long-range reconnaissance capability. The system will be used during periods of military hostilities and in other situations in which the United States military forces may be confronting foreign military forces.

The SR-71 uses the same J58 engine as the experimental interceptor previously announced, but it is substantially heavier and it has a longer range. The considerably heavier gross weight permits it to accommodate the multiple reconnaissance sensors needed by the Strategic Air Command to accomplish their strategic reconnaissance mission in a military environment.

This billion-dollar program was initiated in February of 1963. The first operational aircraft will begin flight testing in early 1965. Deployment of production units to the Strategic Air Command will begin shortly thereafter.

Appropriate members of Congress have been kept fully informed on the nature of and the progress in this aircraft program. Further information on this major advanced aircraft system will be released from time to time at the appropriate military secret classification levels.

Although President Johnson’s announcement had no impact on the status of the program, the Air Force was now under great pressure to get the first aircraft completed and shipped to Lockheed’s Palmdale facility by October. Difficulties with vendors continued to plague the program. Finally, on October 29, 1964, the first SR-71 was surreptitiously delivered by truck convoy from Burbank to Palmdale for final assembly and preflight preparations. Engine runs were initiated on December 18, 1964. Three days later, the first taxi tests were undertaken. In his journal, Kelly Johnson wrote, “A large number of SAC people were here to see taxi test of aircraft 950. They were very much impressed with the smooth operation. I delayed the flight of the aircraft one day, due to unfavorable weather and to get it in better shape to fly.”

The next day, December 22, 1964, the first SR-71, with Skunk Works test pilot Bob Gilliland at the controls, flew aircraft 950 for the first time. Departing from Lockheed’s Air Force Plant 42 facility at Palmdale, it remained airborne for just over an hour and reached a speed in excess of one thousand miles per hour. Although the first SR-71 flight had been completed with few difficulties, ongoing flight testing of the aircraft had not been problem free.

During April 1965, fuel and hydraulic difficulties led to numerous test flight cancellations. Johnson noted, “We have gone through very extensive reworks of the electrical system and tank sealing on the SR-71s. Category 1 tests are way behind schedule, but so are Category 2 tests. The Air Force are very understanding. Our major problem now has to do with the range, where we are about 25% short. We have made our speed, altitude, and are getting good results with the sensor packages.”

“EJECT, EJECT!”

The SR-71 flight test program, conducted at Palmdale, was not without its accidents. The first accident involved aircraft 952. On January 25, 1966, Skunk Works test pilot Bill Weaver and his back seater, Jim Zwayer, were to evaluate procedures for improving high Mach cruise performance by reducing trim drag. Although not a true ejection out of the SR-71, the following story told by Weaver is priceless in conveying the experience of departing a Blackbird at an altitude of fifteen miles and speed of Mach 3.2:

Among professional aviators, there’s a well-worn saying: Flying is simply hours of boredom punctuated by moments of stark terror. But I don’t recall too many periods of boredom during my thirty-year career with Lockheed, most of which was spent as a test pilot.

By far, the most memorable flight occurred on January 25, 1966. Jim Zwayer, a Lockheed flight-test specialist, and I were evaluating systems on an SR-71 Blackbird test from Edwards Air Force Base. We also were investigating procedures designed to reduce trim drag and improve high- Mach cruise performance. The latter involved flying with the center of gravity located further aft than normal, reducing the Blackbird’s longitudinal stability.

We took off from Edwards at 11:20 a. m. and completed the mission’s first leg without incident. After refueling from a KC-135 tanker, we turned eastbound, accelerated to Mach 3.2 cruise speed, and climbed to seventy-eight thousand feet, our initial cruise-climb altitude.

Several minutes into the cruise, the right engine inlet’s automatic control system malfunctioned, requiring a switch to manual control. The SR-71’s inlet configuration was automatically adjusted during supersonic flight to decelerate airflow in the duct, slowing it to subsonic speed before reaching the engine’s face. This was accomplished by the inlet’s center-body spike translating aft and modulating the inlet’s forward bypass doors.

Normally, these actions were scheduled automatically as a function of Mach number, positioning the normal shock wave (where air flow becomes subsonic) inside the inlet to ensure optimum engine performance. Without proper scheduling, disturbances inside the inlet could result in the shock wave being expelled forward-a phenomenon known as an “inlet unstart.”

That causes an instantaneous loss of engine thrust, explosive banging noises, and violent yawing of the aircraft-like being in a train wreck. Unstarts were not uncommon at that time in the SR-71’s development, but a properly functioning system would recapture the shock wave and restore normal operation.

On the planned test profile, we entered a programmed 35-degree bank turn to the right. An immediate unstart occurred on the right engine, forcing the aircraft to roll further right and start to pitch up. I jammed the control stick as far left and forward as it would go.

No response. I instantly knew we were in for a wild ride.

I attempted to tell Jim what was happening and to stay with the airplane until we reached a lower speed and altitude. I didn’t think the chances of surviving an ejection at Mach 3.18 and 78,800 feet were very good. However, g-forces built up so rapidly that my words came out garbled and unintelligible, as confirmed later by the cockpit voice recorder.

The cumulative effects of system malfunctions, reduced longitudinal stability, increased angle of attack in the turn, supersonic speed, high altitude, and other factors imposed forces on the airframe that exceeded flight control authority and the Stability Augmentation System’s ability to restore control.

Everything seemed to unfold in slow motion. I learned later the time from event onset to catastrophic departure from controlled flight was only two to three seconds. Still, trying to communicate with Jim, I blacked out, succumbing to extremely high g-forces.

Then the SR-71 literally disintegrated around us.

From that point, I was just along for the ride. And my next recollection was a hazy thought that I was having a bad dream-Maybe I’ll wake up and get out of this mess, I mused. Gradually regaining consciousness, I realized this was no dream; it had really happened. That also was disturbing, because I could not have survived what had just happened.

I must be dead. Since I didn’t feel bad-just a detached sense of euphoria-I decided being dead wasn’t so bad after all. As full awareness took hold, I realized I was not dead. But somehow I had separated from the airplane.

I had no idea how this could have happened; I hadn’t initiated an ejection. The sound of rushing air and what sounded like straps flapping in the wind confirmed I was falling, but I couldn’t see anything. My pressure suit’s faceplate had frozen over, and I was staring at a layer of ice.

The pressure suit was inflated, so I knew an emergency oxygen cylinder in the seat kit attached to my parachute harness was functioning. It not only supplied breathing oxygen but also pressurized the suit, preventing my blood from boiling at extremely high altitudes. I didn’t appreciate it at the time, but the suit’s pressurization had also provided physical protection from intense buffeting and g-forces. That inflated suit had become my own escape capsule.

My next concern was about stability and tumbling. Air density at high altitude is insufficient to resist a body’s tumbling motions, and centrifugal forces high enough to cause physical injury could develop quickly. For that reason, the SR-71’s parachute system was designed to automatically deploy a small-diameter stabilizing chute shortly after ejection and seat separation. Since I had not intentionally activated the ejection sequence, it occurred to me the stabilizing chute may not have deployed.

However, I quickly determined I was falling vertically and not tumbling. The little chute must have deployed and was doing its job. Next concern: the main parachute, which was designed to open automatically at fifteen thousand feet. Again, I had no assurance the automatic-opening function would work.

I couldn’t ascertain my altitude because I still couldn’t see through the iced-up faceplate. There was no way to know how long I had been blacked out or how far I had fallen. I felt for the manual activation D-ring on my chute harness, but with the suit inflated and my hands numbed by cold, I couldn’t locate it. I decided I’d better open the faceplate, try to estimate my height above the ground, then locate that “D” ring.

Just as I reached for the faceplate, I felt the reassuring sudden deceleration of main-chute deployment.

I raised the frozen faceplate and discovered its uplatch was broken. Using one hand to hold that plate up, I saw I was descending through a clear winter sky with unlimited visibility. I was greatly relieved to see Jim’s parachute coming down about a quarter of a mile away. I didn’t think either of us could have survived the aircraft’s breakup, so seeing Jim had also escaped lifted my spirits incredibly.

I could also see burning wreckage on the ground a few miles from where we would land. The terrain didn’t look at all inviting-a desolate, high plateau dotted with patches of snow and no signs of habitation.

I tried to rotate the parachute and look in other directions. But with one hand devoted to keeping the faceplate up and both hands numb from high-altitude, subfreezing temperatures, I couldn’t manipulate the risers enough to turn. Before the breakup, we’d started a turn in the New Mexico-Colorado-Oklahoma-Texas border region. The SR-71 had a turning radius of about one hundred miles at that speed and altitude, so I wasn’t even sure what state we were going to land in. But, because it was about 3:00 p. m., I was certain we would be spending the night out here.

At about three hundred feet above the ground, I yanked the seat kit’s release handle and made sure it was still tied to me by a long lanyard. Releasing the heavy kit ensured I wouldn’t land with it attached to my derriere, which could break a leg or cause other injuries. I then tried to recall what survival items were in that kit as well as techniques I had been taught in survival school.

Looking down, I was startled to see a fairly large animal-perhaps an antelope-directly under me. Evidently, it was just as startled as I was, because it literally took off in a cloud of dust.

My first-ever parachute landing was pretty smooth. I landed on fairly soft ground, managing to avoid rocks, cacti, and antelopes. My chute was still billowing in the wind, though. I struggled to collapse it with one hand, holding the still-frozen faceplate up with the other.

“Can I help you?” a voice said.

Was I hearing things? I must be hallucinating. Then I looked up and saw a guy walking toward me, wearing a cowboy hat. A helicopter was idling a short distance behind him. If I had been at Edwards and told the search-and rescue unit that I was going to bail out over the Rogers Dry Lake at a particular time of day, a crew couldn’t have gotten to me as fast as that cowboy-pilot did.

The gentleman was Albert Mitchell Jr., owner of a huge cattle ranch in northeastern New Mexico. I had landed about 1.5 miles from his ranch house-and from a hangar for his two-place Hughes helicopter. Amazed to see him, I replied I was having a little trouble with my chute. He walked over and collapsed the canopy, anchoring it with several rocks. He had seen Jim and I floating down and had radioed the New Mexico Highway Patrol, the Air Force, and the nearest hospital.

Extracting myself from the parachute harness, I discovered the source of those flapping-strap noises heard on the way down. My seat belt and shoulder harness were still draped around me, attached and latched. The lap belt had been shredded on each side of my hips, where the straps had fed through knurled adjustment rollers. The shoulder harness had shredded in a similar manner across my back. The ejection seat had never left the airplane! I had been ripped out of it by the extreme forces, seat belt and shoulder harness still fastened.

I also noted that one of the two lines that supplied oxygen to my pressure suit had come loose, and the other was barely hanging on. If that second line had become detached at high altitude, the deflated pressure suit wouldn’t have provided any protection. I knew an oxygen supply was critical for breathing and suit pressurization but didn’t appreciate how much physical protection an inflated pressure suit could provide.

That the suit could withstand forces sufficient to disintegrate an airplane and shred heavy nylon seat belts yet leave me with only a few bruises and minor whiplash, was impressive. I truly appreciated having my own little escape capsule. After helping me with the chute, Mitchell said he’d check on Jim. He climbed into his helicopter, flew a short distance away, and returned about ten minutes later with devastating news. Jim was dead. Apparently, he had suffered a broken neck during the aircraft’s disintegration and was killed instantly.

Mitchell said his ranch foreman would soon arrive to watch over Jim’s body until the authorities arrived. I asked to see Jim and, after verifying there was nothing more that could be done, agreed to let Mitchell fly me to the Tucumcari hospital, about sixty miles to the south.

I have vivid memories of that helicopter flight as well. I didn’t know much about rotorcraft, but I knew a lot about “red lines,” and Mitchell kept the airspeed at or above red line all the way. The little helicopter vibrated and shook a lot more than I thought it should have. I tried to reassure the cowboy pilot I was feeling OK; there was no need to rush. But since he’d notified the hospital staff that we were inbound, he insisted we get there as soon as possible. I couldn’t help but think how ironic it would be to have survived one disaster only to be done in by the helicopter that had come to my rescue.

SR-71A Cutaway drawing

1. Pitot head

2. Alpha/beta probe, incidence and yaw measurement

3. RF isolation segment

4. RWR antennae

5. VOR antennae

6. Interchangeable nose mission equipment bay

7. Loral CAPRE side-looking ground-mapping radar antenna

8. Antenna mounting and drive mechanism

9. Detachable nose bay mounting bulkhead

10. Cockpit front pressure bulkhead

11. Fuselage chine section framing

12. Rudder pedals and control column, Digital Automatic Flight and Inlet Control System (DAFICS)

13. Pilot’s instrument panel

14. Windscreen panels, port only with electrical de-icing

15. Heat dispersion fairing

16. Upward hinging cockpit canopy

17. Ejection seat headrest

18. Canopy actuator and hinge point

19. Pilot’s ‘zero-zero’ ejection seat

20. Side console panel with engine throttle levers

21. Canopy external release

22. Retractable ventral UHF antenna

23. Liquid oxygen bottles (3)

24. Rear cockpit side console with ECM equipment controls

25. Reconnaissance Systems Officer’s (RSO) instrument console and viewsight display

26. SR-71B dual control variant, nose section profile

27. Conversion Pilot’s cockpit

28. Elevated Instructor’s cockpit enclosure

29. RSO’s upward hinging cockpit canopy

30. RSO’s ejection seat

31. Cockpit sloping rear pressure bulkhead

32. Canopy hinge point

33. Honeycomb composite chine skin paneling

34. Astro-navigation star tracker aperture

35. Platform computer

36. Air conditioning equipment bay, port and starboard

37. Avionics equipment, port and starboard, access via nose undercarriage wheel bay

38. ELINT equipment package, port and starboard

39. Twin-wheel nose undercarriage, forward retracting

40. Hydraulic retraction jack

41. Infra-red unit

42. IFF transceiver

43. Flight refueling receptacle, open

44. Recording equipment bay

45. Starboard sensor equipment bays

46. Fuselage upper main longeron

47. Close-pitched fuselage frame structure

48. Forward fuselage fuel tankage, total internal capacity 12,219 US gal of JP-7 (80,280 lb)

49. Tactical Objective Camera (TEOC), port and starboard

50. Operational Objective Camera (OOC), port and starboard

51. Camera-mounting pallets/access hatches

52. Quartz glass viewing apertures

53. Stability Augmentation System (SAS) gyros

54. Forward/center fuselage joint ring frame

55. Center fuselage integral fuel tankage

56. Beta B.120 titanium skin paneling

57. Corrugated wing skin paneling

58. Starboard main undercarriage, stowed position

59. Intake center-body bleed air spill louvers

60. Bypass suction relief louvers

61. Starboard engine air intake

62. Movable conical intake center-body (spike)

63. Spike-retracted (high-speed) position

64. Boundary layer bleed air perforations

65. DIFACS air data probe

66. Diffuser chamber

67. Spike hydraulic actuator

68. Engine inlet guide vanes

69. Pratt & Whitney J58 afterburning turbojet engine

70. Nacelle bypass duct

71. Bypass duct suction relief doors

72. Split nacelle and integral outer wing panel hinged to vertical for engine access/removal

73. Starboard outer wing panel

74. Starboard outboard elevon

75. All-moving starboard fin

76. Fixed fin root segment

77. Afterburner duct

78. Afterburner nozzle

79. Tertiary air doors

80. Exhaust nozzle ejector flaps

81. Variable area exhaust nozzle

82. Starboard inboard elevon

83. Inboard elevon hydraulic actuators (6)

84. Inboard elevon servo

85. Starboard wing integral fuel tank bay

86. Corrugated titanium skin paneling

87. Brake parachute housing

88. Parachute doors

89. Parachute, drogue and release linkage

90. Skin doubler

91. Center fuselage frame structure

92. Aft fuselage integral fuel tankage

93. Inboard elevon servo input linkage and mixer

94. Roll and pitch trim actuators

95. Fuel jettison

96. Port all-moving fin

97. Fin rib structure

98. Torque shaft hinge mounting

99. Rudder hydraulic actuator

100. Rudder servo and yaw trim actuator

101. Fixed fin root rib structure

102. Port engine exhaust nozzle

103. Ejector flaps

104. Port outboard elevon

105. Elevon titanium alloy rib structure

106. Honeycomb composite RAM trailing edge segments

107. Outer wing panel cambered leading edge

108. Leading edge RAM segments

109. Outer wing panel titanium rib and spar structure

110. Outboard elevon hydraulic actuators (14)

111. Outboard elevon servo

112. Engine bay tertiary air intakes

113. Engine nacelle/outer wing panel integral structure

114. Nacelle/outer wing panel hinge axis

115. Port nacelle ring frame structure

116. Inboard wing panel integral fuel tank bays

117. Multi-spar titanium alloy wing panel structure

118. Main undercarriage wheel bay

119. Wheel bay thermal lining

120. Hydraulic retraction jack

121. Mainwheel leg pivot mounting

122. Main undercarriage leg strut

123. Torque scissor links

124. Intake duct framing

125. Outer wing panel/nacelle chine structure

126. Three-wheel main undercarriage bogie

127. Port Pratt & Whitney J58 afterburning engine

128. Afterburner nozzle

129. Afterburner fuel manifold, continuous cruise operation

130. Compressor bypass ducts (6)

131. Engine accessory equipment

132. Inlet guide vanes

133. Port air intake

134. Movable center-body (spike)

135. Spike honeycomb composite skin

136. Spike frame structure

137. Inboard leading edge RAM wedges

138. Leading edge spar

139. Inner wing panel leading edge integral fuel tankage

140. Wing root/fuselage attachment root rib

141. Close pitched fuselage frames

142. Wing/fuselage chine blended fairing panels

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