SR-71 Breakup

chas smith R.I.P. · From: Encino, CA, USA

A friend, who is a pilot, sent me this and since there are steel players who are airplane enthusiasts, I thought I'd pass it along. Keep in mind, the SR-71, the fastest 'conventional' jet airplane was designed with slide rules back in the 1950's and came on line in 1964.

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. "For those who fly....or long to." Contrails is an Aviation
Week & Space Technology initiative to capture the untold stories that
collectively make up the rich lore of aviation and space DH

Jim Phelps · From: Mexico City, Mexico

Wow. That is nothing less than amazing.

Even more amazing, I'd bet the farm that it's just one of many he could tell.

Imagine this being your everyday job.

These guys deserve a lot of respect.

Charlie McDonald · From: out of the blue

Very scary; heaven to hell in seconds.
Amazing aircraft; 100 mi. turn radius.

Charles Curtis · Posted 6 Sep 2005 3:41 pm

Hi Chas, just curious here because when I served as an airborne loadmaster, the CG, (center of gravity) had to be located in the forward third of the MAC (mean aerodynamic chord) or the chances of the aircraft getting off the ground could be diminished. Maybe your friend could explain a little more; I'm interested.

Tom Jordan · From: Wichita, KS

Thanks Chas,

Great story. I had read it previously in the book titled (I think) SR-71 Blackbird...a really good account of the developement and deployment of the "Habu".

Tom Jordan

Earnest Bovine · From: Los Angeles CA USA

Charlie McDonald · From: out of the blue

That's some G's.

Ray Minich · From: Bradford, Pa. Frozen Tundra

quote:
Unbelievably good luck is the only explanation for my escaping
relatively unscathed from that disintegrating aircraft.

Oftentimes that's all that's left.

I escaped unscathed from this aircraft in 1976 'cause I was a dumba$$ tourist trying to take pictures. MP's weren't smiling, and the German Shepherd looked hungry.

[This message was edited by Ray Minich on 07 September 2005 at 12:17 PM.]

Steve Robinson · Posted 7 Sep 2005 3:54 pm

Chas,
Thanks for sharing that hair-raising story. Not many folks have survived supersonic instability/breakup to tell about it. I have a couple of buddies who flew the SR-71, and they all have good tales to tell! As for loading fwd of the CG, taking the wing supersonic alters the center of lift significantly.

I'm trying to think of some way to relate this to PSG!! I'm sure cabinet drop is Mach number dependent... how's that?
Steve

Michael Johnstone · From: Sylmar,Ca. USA

Here's another tense tale for all of us steel player/pilots,avaition enthusiasts(and astronauts).

This is a good first person report from a helicopter crewman in the New Orleans area of responsibility. I recieved this today from an acquaintance via e-mail:

I am still trying to unwind from the
caffeine/sugar rush you build up sitting 12 hours in a hole drinking coffee
and eating snacks instead of real meals. So I thought I would share:

It's still a mess, our wing is providing back haul communications, forward
linking sensor data, food, water, fuel, and aircraft but at times it feels
like we are pissing on a forest fire. It could be the constant UAV feed that
play on the big screen, or the never ending stream of MISREPS we copy, but
it's still going on strong. We have guys who literally got home from over
seas are now working in the area, hell of a welcome home... We have been
cleared to engage hostiles which pretty much put an end to that stupidity.
Even crack head gang bangers will not tangle with a brace of GAU-2s. I am
supposed to be on leave (vacation) right now (doing the SEAL-160 run) but,
I will stay in place until we have things better sorted out, besides we have
no/limited fuel in my neck of the pan handle right now.

got this from my old crew thought I would pass it along.

We left Tucson Last Wednesday in the early afternoon heading to New Orleans
to render whatever assistance we could. It is an understatement to say that
we had any idea what we were up against, but we did speculate along the way
to help prepare ourselves for what we might see there. We had hoped to make
it in one shot straight across the country to expedite our arrival to
Jackson Mississippi, but ran out of crew duty day along the way and had to
stay overnight in Dallas-Ft. Worth. It ended up taking us 9 hours of flying
to get to Jackson because of 25 knot headwinds along the way. Right now all
of the Air Force Rescue assets are staging out of the international airport.
We have every available HH-60G from the Reserve, Active Duty, and the Guard
here at the moment, somewhere in the neighborhood of 32 helicopters. It's
the most I have ever seen in one location ever and if it were other
circumstances I would consider it more impressive...Seeing New Orleans makes
this entire operation from a community perspective pale by comparison. After
we arrived they immediately put us into crew rest...we would have to wait
until Thursday to see the city.
Thursday we figured out we were working 12 on and 12 off, which really means
your in 2 hours prior to take-off, then you fly around 10 hours straight,
then you are debriefing and preparing for tomorrow for another 2 hours
before you get to head to bed. So it really is a 14 to 18 hour day by the
time it's really over. I could go into detail about the rigors of flying 10
hours straight in a helicopter, but I can't adequately describe the effect
it has on you for an extended period of time. Prior to this I had done an 8
hour day with a 2 hour break halfway through...not quite the same, but
definitely not enough to prepare you for what we've gone through. It's an
hour flight from Jackson to Orleans, its hot, humid and boring. All that
changes the moment you get into the city.
I can tell you right now that New Orleans is gone. 90 percent of the city is
under water. You cannot, even from seeing the news understand the scope and
the depth of complete destruction that has taken place there. If you have
never been to NO, then you missed your chance. This city is a total loss.
Most of the city is under at least 4-7 feet of water, the area nearest the
17th street canal is up to the roofline. The only way around the city is by
boat, or helicopter. Most of the elevated interstates are underwater except
for the clover-leafs. There is no road access from the International airport
west of the city to the Mississippi River. East Orleans on the other side of
the river is completely underwater all along Lake Ponchartrain (Sp?).
Where to begin...I'll start with the totals... our crew has flown almost 40
hours in 4 missions, we have picked up 79 people, 6 dogs and 2 cats. For the
record, dogs are cool with the helicopter ride, it's just another open
window to hang there head out while they get a ride somewhere; Cats however
are another story...they are not impressed with the rescue effort. I have
performed almost all the pick-ups with the hoist because there are a very
limited number of places to land and most rooftops are not rated for a
20,000 pound helicopter. We've had cases of helicopters breaking through
rooftops and my crew wanted nothing to do with this risk. We initially
started to pick people off rooftops, balcony's, any piece of high ground
they could get to. Some hoists were quick and we were in a hover for 15
minutes. Others were very technical because of the wires and other obstacles
and we were in a hover for 1-2 hours at a time to get just a couple people.
Kids and old people are fun to pick up, their parents and other healthy
adults are not as much fun. Ummm, one note on people in NO, most of them are
very overweight. You can't exactly pluck a 300 pound woman from a rooftop
and pull her easily into the door of a helicopter when she's dangling from a
slender cable being held up by one of our PJ's. Pulling the combined weight
of them into the door is a very difficult maneuver under regular
circumstances, after doing it all day for hours and hours compounds that.
Combined it can be 600 pounds of swinging weight. That's a lot of momentum.
This is combat flying. I'd say it's absent of only the bullets being thrown
in your direction, but we've had instances of that too. The number of
helicopters flying makes this the most hazardous I have ever seen. You can
be hovering picking up people from one rooftop and there will be 4-5 or 6,
maybe more, helicopters all doing the same within a quarter mile radius of
you at the moment. All trying to do it safely while trying to maneuver in
the same airspace and do all the other associated things that come with
flying. It's dense to say the least. The water is full of sewage, fuel from
cars, rotten "Stuff", dead bodies floating in the water...and all of it ends
up as spray from the helicopter rotor wash as you hover there trying to pick
people up.
We hit the tanker for gas, drop people off at the international airport for
triage and return to the city to do it all over again. During the day you
are trying to find people in windows and doors, on the ground, anywhere. At
night you are looking for lights of any kind that might indicate life exists
in any structure. We are flying straight through from noon to 10 pm. When it
gets dark we goggle up and continue the search with NVG's. There is no
command and control and everything is complete chaos. But it's where we work
the best, we have a simple mandate: Conduct random search and rescue
operations. Recover people you find, assess or triage them and deliver them
to the appropriate collection point...repeat. 24/7.

chas smith R.I.P. · From: Encino, CA, USA

Steve, thanks for the answer on CG, this stuff is over my head, so to speak. I did have a friend, at the gym, over a decade ago who had done a little work with the SR-71, but was mostly involved with the YF-22. And when the SR-71 was declassified, one of my co-worker's father had een a pilot, and while he wouldn't say how fast or high it would really go, he said it was significantly above the admitted 3.6.

Of course I asked Michael, the engineer, if it would do Mach5 and his reply was simply, at Mach5 the wings come off.

How does this relate to pedal steel, well one time I had the woman half of a swing dancing couple, spin out of control and land on my Bigsby. Her "suit" withstood the forces leaving me with only a few bruises and minor whiplash.....

chas smith R.I.P. · From: Encino, CA, USA

I just read Michael's post, this is all so unbelievable and heart-rending. I had a shop in New Orleans in 1971, above the Atlantis Restaurant and across rom the Old Mint, and I lived out on Carondelet.

Charlie McDonald · From: out of the blue

Cool account, Michael; I'd almost rather be in a Blackbird than hanging for 2 hours with that pounding; paints quite a picture of the rescues.

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