there's an old airplane story that's
called the LA speed check and go
something like this a pilot of a
single-engine Cessna calls the Los
Angeles air route Control Center and
asked for a speed check wants to know
how fast he's going and the senator
tells him he's going about 90 knots
immediately thereafter another pilot
someone in say a twin engine Beechcraft
trying to make fun of how slow the
Cessna goes ask for a speed check and
the senator tells him that he's going
around a hundred and twenty-one knots
but almost immediately thereafter
another voice chimes in and this is a
Navy pilot who's flying at an f-18
fighter jet and he doesn't really need
to know how fast he's going he's got an
airspeed indicator inside his cockpit
he's just trying to prove to everybody
out there on the frequency that he's
flying the biggest baddest fastest jet
in the world and to all those Cessna and
Beechcraft owners how fast our plane
really flies and the LA Center radios
back that he's going an impressive six
hundred and twenty knots and you think
that would be enough to win this little
contest
what another voice casually asked this
is Aspen 3-0 can you give us a speed
check and after a moment the Center
responds Aspen 3-0 we have you going
1993 knots that story which was related
in Bryan Scholz book sled driver flying
the world's fastest jet shows how
extreme the world's fastest
air-breathing manned jet aircraft in
history the Lockheed sr-71 blackbird
really was but you know if you find an
airplane that can go more than three
times the speed of sound and almost into
outer space one thing is important you
don't want to fall out and if you did it
would be history that deserves to be
remembered in late 1957 the CIA
approached the defense contractor
Lockheed asking them to secretly design
an undetectable spy plane the project
called Archangel was to be handled by
the Lockheed advance development
projects team led by legendary aircraft
engineer Kelly Johnson Lockheed advance
development project unit was called the
skunk works a nickname it had gotten
since the original facility had been
built near at an old plastics
manufacturing plant that produced awful
smells in 1955 the sky
quirks had gotten a CIA contract to
build an ultra high altitude spy plane
designed for flying over the Soviet
Union and photographing sites of
strategic interests the plane was the
Lockheed u2 a plane able to fly at such
a high altitude that it was thought to
be outside Soviet radar capacity and
invulnerable to Soviet fighter aircraft
and ground-to-air missiles the new
request was for a plane that could go
even higher and faster than the u2 the
need for such a plane was highlighted
when the Soviet s75 ground-to-air
missile successfully shot down the u2 in
May of 1960 causing an international
incident project Archangel produced a
single-seat reconnaissance plane called
the a12 and the two-seat fighter
interceptor prototype called the yf-12
that set speed and altitude records in
1965 while the f12 never made production
it was used as a marble for an Air Force
reconnaissance plane that was longer
than the a12 held more fuel and had a
two-seat cockpit the plane ended up with
the designation SR for a strategic
reconnaissance 71 painted a blue so dark
that was almost black to camouflage the
plane against the night sky it earned
the nickname blackbird a total of 36
sr-71 black birds were manufactured the
sr-71 was designed for flight at over
Mach 3 with a flight crew of two the
pilot in the forward cockpit and the
reconnaissance systems officer operated
the surveillance systems and equipment
from the rear cockpit and directing
navigation on the mission flight path
traveling at supersonic speeds meant
that the outside of the aircraft would
get very hot more than 600 degrees so
lucky could not use aluminum the plane
was 92% titanium inside and out while
titanium has low density in high
strength it offers unique challenges in
manufacturing but most problematic is
that the ore needed to make titanium is
rare and in short supply in the United
States the major supplier of the ore was
the Soviet Union the u.s.
surreptitiously worked through
third-world straw buyers to acquire the
or the plane was designed to reduce its
radar cross-section an early version of
stealth that combined with its speed and
altitude made the plane virtually
invulnerable to countermeasures the
sr-71 was powered by two pratt & whitney
j58 engines this axial-flow turbojet
engine was designed
be most efficient it speed mach 3.2
although later experience showed that it
may have been even more efficient at
higher speeds but that was a complex
problem at those speeds air coming
inside the engine had to be slowed to
subsonic speeds to maintain consistent
flow to the compressor this was done by
moving a cone that was called a spike
inside each inlet but as the airflow
reduces it causes a disturbance a shock
wave called normal shock in in a locked
computer within the engine would control
a complex system of bleed tubes and
bypass doors to handle the pressure
however the early analog computers would
often have difficulty keeping up with
rapidly changing flight conditions if
the pressure inside the engine became
too great it could blow back off the
front of the engine disrupting airflow
and what was called an inlet unstart the
unstarted initially causes immense drag
because of the forward blowback and
would often extinguish the afterburner
causing a symmetrical thrust and violent
yaw inputs from the autopilot system and
the pilot could counter the yargh
recapture the shock wave and return the
plane to normal operation but an unstart
would almost always result in a rough
ride sometimes accompanied by violent
banging noises and counter yarra the
yarn can be so violent that the pilot
helmets would bang against the canopy
the effect was described as like being
in a train wreck
there were also challenges given the
plane's altitude ceiling above 80,000
feet a normal pilots mask could not
provide enough oxygen for a pilot above
about 40,000 feet and breathing becomes
impossible above 49 thousand feet as the
pressure at which the lungs excrete
carbon dioxide exceeds outside air
pressure at 62,000 feet some 18 plus
kilometers the pressure reaches
something called the Armstrong limit
named after the pioneering flight
position who identified the phenomena
the Armstrong limit represents the
altitude above which atmospheric
pressure is sufficiently low that water
boils at the normal temperature of the
human body simply put a human cannot
survive above this limit as their blood
would literally boil to a stand the
conditions aircrews for high-altitude
craft have to wear pressurized suits in
the terrible scenario where an air crew
had to ejected extreme altitudes the
suit had a built-in oxygen tank designed
to keep the suit pressurized the sr-71
performance would subject
extreme conditions planes returning from
missions often would have rivets ripped
out or panels that were delaminated or
parts like air intakes it had to be
repaired or replaced and one place where
the extreme conditions that affected
this airplane showed was in aircraft
losses of just 32 sr-71s built 12 were
lost to accidents and the first of those
accidents occurred during the planes
testing phase of January 25th 1966 the
plane tail number nine five two took off
from Edwards Air Force Base at 11:20
a.m. the pilot was bill Weaver an
experienced Lockheed test pilot
Jim's where a Lockheed flight test
reconnaissance and navigation system
specialist was in the rear the two were
investigating procedures designed to
reduce trim drag and improve high Mach
cruise performance the latter involved
flying with the plane configured with
the center of gravity located further
aft than normal the first leg of the
flight went normally and the sr-71 was
refueled by a kc-130 tanker Weaver
increased the plane speed to mach 3.2
and climbed to 78,000 feet
several minutes later the right engine
automatic Inlet control system failed
requiring to switch to manual control
this was common in the early test phase
of the aircraft
but as Weaver took the plane into a
scheduled 35 degree Bank turned to the
right the right engine suffered a
dreaded Inlet unstart the resulting
asymmetric thrust caused the plane to
roll further right
increasing the bank to 60 degrees and
pitch up Weaver yanked the control stick
as far left as it would go but it seemed
to have no effect
knowing the chances of surviving an
ejection at Mach 3 point one eight and
seventy eight thousand eight hundred
feet was not very good
Weaver hoped to be able to get the plane
to a lower altitude and speed to allow a
safe ejection
he yelled FERS where to stay with the
planes as they attempted to gain control
but the g-forces were so strong that the
words came out garbled and
unintelligible part of the problem was
the nature of the test flight moving the
center of gravity aft of normal specs
reduced the Blackbirds longitudinal
stability given the yaw from the inlet
unstart the reduced longitudinal
stability combined with the increased
angle from the turn and the speed and
altitude the cumulative forces simply
exceeded the automatic system's ability
to control the plane the radical
g-forces were beyond human limits and
Weaver in
wäôre lost consciousness neither able to
activate the ejection system the
airframe initially broke apart after the
cockpit sr-71 tail number nine five two
disintegrated in midair back at Edwards
the plane disappeared from radar and
they lost radio contact the initial
assessment was was that the flight crew
could not have survived such a violent
breakup at that speed in altitude when
Bill Weaver woke up he thought he was
having a bad dream his next thought was
no one could survive what just happened
therefore I must be dead but as he
became more aware he could hear rushing
wind what sounded like straps flapping
he was alive and had somehow separated
from the aircraft despite not activating
the ejection system in fact he had been
thrown clear in the accident his
ejection seat was still with the
wreckage of the plane falling to earth
at that very moment the flight suit had
apparently done its job with the oxygen
tank that was attached to the parachute
harness inflating the suit to keep it
pressurized that was itself astounding
given the violence of the planes breakup
and it was a good thing otherwise
Weaver's blood would be boiling
but the visor on his helmet was iced
over well I could tell that he was
falling he couldn't see 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
the parachute system was supposed to
initially deploy a small chute that
should keep him from tumbling but he
couldn't be sure that it had deployed as
he had no idea how long he'd been
unconscious he didn't know how far up he
was or how long before he might
experience the rapid deceleration caused
by colliding with the earth but the
small chute had deployed and he was
falling vertically the main chute should
open automatically at 15,000 feet but it
could not be sure the automatic systems
were functioning he tried to find the
manual activation for the chute but his
hands were numb by cold and with the
suit inflated he couldn't find it but
just then he felt the reassuring sudden
deceleration caused by the opening of
the main chute he lifted the faceplate
on his visor only to find that the latch
was broken and he had to hold it up
given the plane speed he couldn't even
be sure which state he was going to land
in and the ground below looked desolate
he could see the burning wreckage of the
airplane on the ground some miles away
and most importantly he was reassured to
see Jim's way or chute open some
distance off despite being an
experienced test pilot we
never actually jumped out of an airplane
before this was his first parachute
landing and he said it went okay despite
nearly landing on what appeared to be a
very surprised antelope given the size
that the search area must be he figured
he'd have to figure out how to survive
the night before he could expect rescue
but on that count he was wrong he was
busy trying to collapse his parachute
while having to hold up his faceplate
when he heard someone behind him say can
I help you with that it turns out the
plane had broken apart over a New Mexico
ranch owned by Albert J Mitchell jr.
Mitchell and several ranch hands were
Brandon Colts when they heard a noise
and saw parachutes descending from the
sky several minutes later Mitchell was a
pilot and owned a small Hughes 300
helicopter and it immediately flown to
where Weaver had landed after helping
Weaver collapse the chute Mitchell flew
to where Jim's waders chute had landed
only to find that swea was deceased his
neck had apparently snapped when the
airplane broke up after the accident
Weaver found out that the flapping noise
that he'd been hearing as he was falling
was because the heavy nylon straps it
had strapped him into the aircraft had
been shredded by the accident and that
shows how impressive it was that his
flight suit held together through all of
that but he also found out that the
oxygen tank that connected to his flight
suit was connected by two tubes and one
had torn loose and the other was barely
hanging on if that second tube had torn
loose then the flight suit would not
have inflated and he would have died
Albert Mitchell flew Weaver to the
nearest hospital which was in Tucumcari
New Mexico and Weaver remembers being
terrified because Mitchell kept a little
helicopter speed above the red line for
the entire trip and Weaver was thinking
how ironic would be that if he survived
falling out of an sr-71 at 78,000 feet
only to die in a little helicopter on
the way to the hospital lockheed decided
as a result of the accident to
discontinue any testing of the sr-71
that put the center of gravity aft of
Speck's and they solve some other
problems through aerodynamic means and
eventually a digital computer replaced
the analog computer that controlled the
air intakes and those intake unstart
became much more rare the Air Force
retired the sr-71 in 1998 and NASA
retired theirs in 1999 but there are
persistent rumors that the skunk works
is working on a successor to the sr-71
that some people claim will be twice as
fast in its 33 years of service
where was the only sr-71 crew member to
die in a flight accident bill Weaver was
back flying sr-71s within a week and
eventually became Lockheed chief test
pilot he retired and lives in Carlsbad
California I hope you enjoyed this
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