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
