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SR-71: A pilots story

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  • SR-71: A pilots story

    An interesting little "story" from a blackbird driver I enjoyed, thought you might....

    One Set of Wings Almost Lead to Another

    Bill Weaver : SR-71 BREAKUP

    Among professional aviators, there's a well-worn saying: Flying is
    simply hours of boredom punctuated by moments of stark terror. And yet,
    I don't recall too many periods of boredom during my 30-year career with
    Lockheed, most of which was spent as a test pilot. By far, the most
    memorable flight occurred on Jan. 25, 1966. Jim Zwayer, a Lockheed
    flight test reconnaissance and navigation systems specialist, and I were
    evaluating those systems on an SR-71 Blackbird test from Edwards AFB,
    Calif. 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 (CG) located further aft than normal,
    which reduced 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 a Mach 3.2- cruise speed and climbed to 78,000 ft., our
    initial cruise-climb altitude. Several minutes into 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 air flow
    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 by 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-deg. 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 ft. 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 2-3 sec. Still trying to communicate with Jim, I blacked out,
    succumbing to extremely high g-forces. The SR-71 then literally
    disintegrated around us. From that point, I was just along for the ride.

    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. Therefore, 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 had somehow 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 face
    plate 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 system--and assuming all
    automatic functions depended on a proper 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 15,000 ft. 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
    face plate. 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 face plate, try to
    estimate my height above the ground, then locate that "D" ring. Just as
    I reached for the face plate, I felt the reassuring sudden deceleration
    of main-chute deployment. I raised the frozen face plate 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 face plate 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 100 mi. 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 300 ft. 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 training. 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 face plate 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 had. The
    gentleman was Albert Mitchell, Jr., owner of a huge cattle ranch in
    northeastern New Mexico. I had landed about 1.5 mi. 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 me 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 10 min. 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 60 mi. 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. However, we
    made it to the hospital safely--and quickly.

    Soon, I was able to contact Lockheed's flight test office at Edwards.
    The test team there had been notified initially about the loss of radio
    and radar contact, then told the aircraft had been lost. They also knew
    what our flight conditions had been at the time, and assumed no one
    could have survived. I briefly explained what had happened, describing
    in fairly accurate detail the flight conditions prior to breakup. The
    next day, our flight profile was duplicated on the SR-71 flight
    simulator at Beale AFB, Calif. The outcome was identical. Steps were
    immediately taken to prevent a recurrence of our accident. Testing at a
    CG aft of normal limits was discontinued, and trim-drag issues were
    subsequently resolved via aerodynamic means. The inlet control system
    was continuously improved and, with subsequent development of the
    Digital Automatic Flight and Inlet Control System, inlet unstarts became
    rare. Investigation of our accident revealed that the nose section of
    the aircraft had broken off aft of the rear cockpit and crashed about 10
    mi. from the main wreckage. Parts were scattered over an area
    approximately 15 mi. long and 10 mi. wide. Extremely high air loads and
    g-forces, both positive and negative, had literally ripped Jim and me
    from the airplane. Unbelievably good luck is the only explanation for my
    escaping relatively unscathed from that disintegrating aircraft. Two
    weeks after the accident, I was back in an SR-71, flying the first
    sortie on a brand-new bird at Lockheed's Palmdale, Calif., assembly and
    test facility. It was my first flight since the accident, so a flight
    test engineer in the back seat was probably a little apprehensive about
    my state of mind and confidence. As we roared down the runway and lifted
    off, I heard an anxious voice over the intercom. "Bill! Bill! Are you
    there?"

    "Yeah, George. What's the matter?" "Thank God! I thought you might have
    left." The rear cockpit of the SR-71 has no forward visibility-- only a
    small window on each side--and George couldn't see me. A big red light
    on the master-warning panel in the rear cockpit had illuminated just as
    we rotated, stating, "Pilot Ejected." Fortunately, the cause was a
    misadjusted microswitch, not my departure.

    Bill Weaver flight tested all models of the Mach-2 F-104 Starfighter and
    the entire family of Mach 3+ Blackbirds--the A-12, YF-12 and SR-71. He
    subsequently was assigned to Lockheed's L-1011 project as an engineering
    test pilot, became the company's chief pilot and retired as Division
    Manager of Commercial Flying Operations. He still flies Orbital Sciences
    Corp.'s L-1011, which has been modified to carry a Pegasus
    satellite-launch vehicle (AW&ST Aug. 25, 2003, p.
    56). An FAA Designated Engineering Representative Flight Test Pilot,
    he's also involved in various aircraft-modification projects, conducting
    certification flight tests.

  • #2
    Awesome story. Thank you!

    Comment


    • #3
      Just heard about this in discovery prog about supersonic speed.
      Hala Madrid!!

      Comment


      • #4
        "Pilot Ejected."

        Still, if even for a second or two, I'd be thinking, "If I live, I'll get to say that I soloed in an SR-71 Blackbird, and everybody in the bar would think I was coolest guy they'd ever met when I proved it was true."

        Comment


        • #5
          Originally posted by indianguy4u
          Just heard about this in discovery prog about supersonic speed.
          Same here, saw it on the Discovery Channel just about a week ago, if I'm not mistaken. Remembered the part when that pilot said he saw a cowboy who came to his rescue, it was like a movie, hard to believe!

          SR-71 should have had an escape capsule, like F-111.

          Comment


          • #6
            Incredible.

            Comment


            • #7
              Originally posted by Captain Drunk
              Same here, saw it on the Discovery Channel just about a week ago, if I'm not mistaken. Remembered the part when that pilot said he saw a cowboy who came to his rescue, it was like a movie, hard to believe!

              SR-71 should have had an escape capsule, like F-111.
              I would say that this story is proof that the pressure suit was completely adequate to the task. Had the pilots actually ejected, they'd have both survived. If they relied on an escape module, it too would've been ripped apart as the aircraft disintegrated.

              It is one hell of a story.
              Last edited by Bill; 14 Jan 06,, 00:02.

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