SR-71 inflight breakup

[Slasher]

One very lucky bugger.

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.

[Beef Raiser]

Thank you Captain Slash, a very interesting article.

[Yamagata ken]

Jeebus.

[Cacophonix]

To have escaped, unscathed, in such an in-flight breakup scenario at such a high Mach number and altitude is extraordinary indeed. The scenario described here in the SR71 accident was far more extreme, even, than the accident that befell the pilots in the VSS Enterprise crash in which the aircraft also disintegrated, killing the co-pilot and ejecting the unconscious pilot at a relatively high altitude at just over Mach 1. In the latter case the pilot, whose parachute was automatically opened by a barometric trigger, survived with substantial injuries. The pilot did not eject per se as the aircraft was not equipped with such and he simply fell in his seat after the initial breakup.

VSS Seat - Not an ejector seat.jpg (54.44 KiB) Viewed 447 times

VSS Enterprise breakup.jpg (56.36 KiB) Viewed 444 times

The National Transportation Safety Board has released a summary of an interview it conducted with Scaled Composites pilot Pete Siebold, who was in command of SpaceShipTwo when it broke up over the Mojave Desert last Oct. 31 during a flight test. Siebold was thrown clear of the ship and managed to parachute to safety, but not before passing out and struggling to activate his oxygen system. Co-pilot Mike Alsbury was not as lucky; he died in the crash.

The following excerpt describes Siebold’s descent and landing from about 10 miles up, the extent of his injuries, and his treatment by medical personnel in the desert and at Antelope Valley Hospital.

Because he considered this a “high-risk” flight he stated that he took extra precautions and took time to think through scenarios that might happen and how he would rapidly respond in an emergency and activate his parachute and oxygen cylinder. About 10-15 minutes prior to release there was a period of low workload when he was able to physically feel for the parachute D-ring rip cord, oxygen activation pud, and the dual-lever seatbelts to improve his “muscle memory” in the event of an emergency. This was not a written procedure, but something he personally did on some flights.

The last thing he recalled in SS2 was a very violent, large pitch-up with high Gs, and grunting noises. He heard a loud bang followed very quickly by signs of a rapid cabin depressurization. In the background he heard the sound of “paper fluttering in the wind,” which he believed was the sound of pieces of the cabin coming apart. There was then a period when he had no recollection, which he attributed to “g-lock” due to the unexpected onset of high Gs for which he was not prepared.

The next thing he remembered he was outside of SS2 and he perceived that he was still at high altitude, above the haze layer. He heard a high frequency whistling noise and his helmet and mask were no longer straight on his face. He felt the mask was peeled up a little bit and both it and the helmet were twisted to the left. His believed the mask seal was compromised at that time. At some point he became aware that the visor had been ripped off. It felt as if something was continuously trying to rip his helmet off. He opened his eyes and saw a wide expanse of desert from a high altitude. He was falling in a stabilized position with his head slightly down and he had to look up to see the horizon. He was not tumbling.

He did not recall what actions he took first, but he remembered attempting to activate the oxygen system by pulling on it “many times.” He could not be certain whether he attempted this activation at this time or during a later period of consciousness. He did not specifically recall being in his seat but remembered unfastening the dual-lever seatbelt without difficulty and assumed the free fall with his arms out and legs apart.2 He recalled no pain. He then experienced another period of unconsciousness or lack of memory.

The next thing he remembered was a “sudden jolt” when the parachute opened and feeling as though he had been asleep. He did not pull the D-ring for the rip cord and believed the CYPRES device had activated the parachute. He described the parachute opening as “gentlemanly… it was not harsh.” It was difficult to estimate the altitude but he estimated it was somewhere between 10,000 and 20,000 feet, noticeably lower than his previous period of consciousness. He looked up and checked on the canopy to ensure it was properly deployed. His eyesight was “degraded” and events began to “slow down” in his mind allowing him to absorb more information. He again recalled attempting to activate the oxygen but was unsure at what point in he made the attempts. It was either during one or both periods of consciousness. He tried “many, many, many times” and “just got the feeling” that it was not working and he never got oxygen flow. He also stated that he “didn’t know what to expect or what it should feel like… it just didn’t feel like it did anything.” When asked if he used one or two hands he stated that he only used one hand – his left. He further stated that “you can’t really do anything with your right hand with the oxygen. It’s not a very convenient angle so I would assess it as a one hand operation.” When asked if he could see what he was pulling on he stated that he could not recall.

The chase airplane began to circle him and he became aware that he had sustained injuries. His eyes hurt and it was very bright and difficult to see. He could not raise his right arm and assumed it was dislocated. He was concerned about the parachute landing fall and did not want to reinjure a previous left foot injury he had sustained years earlier. He wanted to reach the risers to position himself into the right attitude for a proper landing. He manipulated his right arm several times in an attempt to resolve the dislocation but he was not successful. He was running out of time and made the decision to put his hands at his sides with his feet and bent knees together. Between about 5,000 and 2,000 feet he noticed a very high ground speed and became concerned about landing and being dragged through the desert, but by the time of touchdown the surface winds were calm. He descended in a very slow spiral with no noticeable ground track.

Upon touchdown, he could not roll to one side because of a lack of directional control and fell forward into a creosote bush. He did not attempt to absorb any of the energy with his legs. The parachute drifted over the top of the bush and immediately collapsed. He sat up and began to become more aware of the severity of his injuries. His eyesight continued to degrade and was painful. He could not keep his eyes open and he never opened his right eye again until the emergency responders arrived. His right arm was bleeding and his flight suit was saturated with blood but it did not appear to be actively bleeding so he was “not overly concerned about it.” He did not perceive any lower body injuries. As he was moving to take the parachute harness off he felt a “clunking noise” in his chest and was concerned about a spinal fracture. Therefore, he decided not to move until the emergency responders arrived. He took his helmet off and may have taken his glove off. His right hand was numb, as if he were out throwing snowballs without gloves while his left hand felt normal. He did not release the Capewells on the parachute harness, although he was prepared to do so if he began to get dragged.

The Extra chase plane circled him numerous times while he was both in the air and on the ground. He recalled waving to them to show them he was conscious. He recalled that it took “a really long time for the responders [helicopter] to get there,” which surprised him. When they arrived the helicopter landed about 100 yards away. The first helicopter was from the National Test Pilot School. He recalled someone wearing a flight suit from the school and someone dressed in airport firefighting gear. They bundled up the parachute and were going to use it to stabilize him somehow. They examined him and eventually got a backboard and stabilized him on it. His boots were removed and later found on scene. He was taken to a second helicopter which had landed, which he presumed was the “Mercy Air” helicopter. One of the paramedics attempted to start an IV but was unable to until they got on the ground in Lancaster. Once in the emergency room he was cut out of his flight suit and his injuries were addressed.

Upon touchdown, he could not roll to one side because of a lack of directional control and fell forward into a creosote bush. He did not attempt to absorb any of the energy with his legs. The parachute drifted over the top of the bush and immediately collapsed. He sat up and began to become more aware of the severity of his injuries. His eyesight continued to degrade and was painful. He could not keep his eyes open and he never opened his right eye again until the emergency responders arrived. His right arm was bleeding and his flight suit was saturated with blood but it did not appear to be actively bleeding so he was “not overly concerned about it.” He did not perceive any lower body injuries. As he was moving to take the parachute harness off he felt a “clunking noise” in his chest and was concerned about a spinal fracture. Therefore, he decided not to move until the emergency responders arrived. He took his helmet off and may have taken his glove off. His right hand was numb, as if he were out throwing snowballs without gloves while his left hand felt normal. He did not release the Capewells on the parachute harness, although he was prepared to do so if he began to get dragged.

The Extra chase plane circled him numerous times while he was both in the air and on the ground. He recalled waving to them to show them he was conscious. He recalled that it took “a really long time for the responders [helicopter] to get there,” which surprised him. When they arrived the helicopter landed about 100 yards away. The first helicopter was from the National Test Pilot School. He recalled someone wearing a flight suit from the school and someone dressed in airport firefighting gear. They bundled up the parachute and were going to use it to stabilize him somehow. They examined him and eventually got a backboard and stabilized him on it. His boots were removed and later found on scene. He was taken to a second helicopter which had landed, which he presumed was the “Mercy Air” helicopter. One of the paramedics attempted to start an IV but was unable to until they got on the ground in Lancaster. Once in the emergency room he was cut out of his flight suit and his injuries were addressed.


He stated that had a four-part fracture of his right humerus that was not compound. The ball itself was broken as well as broken off the humerus and it was dislocated. He also had a nondisplaced fracture of his right clavicle. He had a small “gash” in his right elbow that was the source of the blood on his flight suit. He had a deep scrape/contusion on his right wrist and multiple scrapes on the back of his right shoulder. He had a lot of bruising on his right chest but did not know how that occurred. He did not recall any bruising on his left side. He had a lot of bruising on the tops of his quadriceps on both legs which were sore for many days. He did not receive an official diagnosis for the “clunking” noise in his right chest but was told it may have been a muscle or cartilage tear between the ribs. Several days after the surgery his left little toe was sore. When it was x-rayed it was determined that it was fractured. He had an abrasion under his chin which he felt was consistent with the location of his chin strap. He had multiple contusions and scrapes on his face. He was initially diagnosed with only corneal scratches in his eyes but he removed a piece of fiberglass from his left eye during his hospital stay. His eyes did not improve as fast as he was told they would so he saw an ophthalmologist after being discharged. The ophthalmologist also removed some foreign matter from his left eyelid and a “silver sliver” from his right cornea. His eyes improved quickly almost immediately after the procedure.

http://www.parabolicarc.com/2015/07/29/ ... two-crash/




https://en.wikipedia.org/wiki/VSS_Enterprise_crash

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