It was only two hours into a routine surveillance mission in 2006, when the pilot of a U-2 spy plane
knew something was terribly wrong. Sudden fatigue, difficulty breathing, and hallucinations had
overwhelmed Kevin Henry, an experienced U-2 pilot. But as his cognitive abilities rapidly declined,
Kevin did one of the most dangerous things one could do while flying at 70,000 feet;
he opened the visor on his pressurized helmet … but the reason, is Not What You Think!
Kevin Henry’s mission started like any other, by putting on his pressurized full body suit. The
U-2 pilot suit is basically a space suit, similar to what astronauts wear, because when cruising at
the brink of space, the air pressure is so low that it can make your blood boil. Literally!
It can also get pretty hot pretty quickly in an air-tight suit, which is why the suit
is connected to a cooling system from the time the pilot puts it on, during transportation and
walking to the airplane , and finally hooked into the cooling system inside the cabin.
But when fully-pressurized, the space suit limits the mobility of the pilot . This is
one of the reasons the U-2 cabins are pressurized, so the suit can be only
partially pressurized as needed. And in the event of a sudden loss of cabin pressure,
the suit has an automatic mechanism to fully pressurize. But the cabin pressure by itself,
doesn’t create the most hospitable environment.
When flying at 70,000 feet the cabin pressure is equivalent to that at 29,000 feet, or what
climbers experience at top of Mount Everest. But the air at these altitudes is so thin,
that each breath pulls in less than a third of the oxygen that you and I are breathing in right now,
which is why those who summit Everest use oxygen tanks for their safety.
This explains why U-2 pilots also need to breathe in pure oxygen when flying,
but what it doesn’t explain is why U-2 pilots start pre-breathing oxygen at
least one hour prior to their flight, before they even get into the cockpit.
High-altitude pilots and scuba divers have two problems in common: number one … and number two!
If you need to pee, you just do. Of course, in the case of pilots,
they have a special contraption that helps them capture the urine,
and yes, there is a female version also. But when it comes to number 2, you just have to hold it in,
which is not a big issue during a 1-hour scuba dive, but not feasible during a 9-hour flight.
Which is why U-2 pilots go on a high protein, low residue diet twenty-four hours prior to take-off,
so everything that they eat can be almost completely absorbed from the gastrointestinal
tract. During the flight, they can also drink and eat via a tube through a port in their helmet.
Speaking of helmets and space suits,
a former NASA engineer developed Ground News, who’s sponsoring today’s video.
This news platform is unlike any news service I’ve ever used. It lets you compare articles
from more than 50,000 sources around the world and across the political spectrum - all in one place.
Like a few days ago, I was reading about the U.S. State Department approving a massive arms sale to
Saudi Arabia and the UAE. Not only could I quickly see how many sources are reporting on the story,
but also the political leaning of those news outlets according to independent third-party news
monitoring organizations. Which was interesting, because the story is heavily reported on the right
and is possibly a blindspot for people who typically read left-leaning news.
Ground News makes it easy to flip through different sources,
see how they’re framing the issue, and read entire articles in one place. I can even filter by bias
or location to see how different countries are covering this news for a more nuanced perspective.
I’ve been a big fan of this app and website for months now, and I can’t recommend it enough.
So go to ground.news/notwhatyouthink and sign up for free, or subscribe to get full
access and support a small team of media outsiders working to make the news more transparent for you.
But number 1 and 2 aside, the real risk that both U-2 pilots
and scuba divers face, is decompression sickness.
When you open the cap on a bottle of soda, the pressure inside the bottle is suddenly released,
which allows the CO2 that was previously dissolved in the liquid under pressure,
to escape in the form of bubbles. Similarly, there are inert gases, mainly nitrogen,
that are normally dissolved in our body fluids and tissues. But when the surrounding pressure
is suddenly reduced, whether it’s water pressure as scuba divers come to surface,
or air pressure when U-2 pilots ascend, those inert gases start leaving the body in the form
bubbles, or simply put, they boil, which In the human body, can cause extreme pain,
bruising, brain damage, and, without treatment, death. The potential for decompression sickness
is not limited to U-2 pilots. The F-22 Raptor can cruise at altitudes greater than 60,000 ft.
But one of the significant breakthroughs in the fight against decompression sickness for
high-altitude pilots was the discovery that breathing 100%
Oxygen before flying could wash out most of the existing nitrogen from the body.
During oxygen pre-breating, the nitrogen stored in tissue and fats moves into the bloodstream,
then into the lungs, from where it leaves the body during exhalation.
That guy is not just chilling there. He is pre-beathing oxygen to ensure a safe flight.
Some U-2 pilots also perform enhanced pre-breathing, which includes a 10-minute
exercise of their upper and lower body at the beginning. This causes additional blood flow and
delivery of oxygen to major muscle groups, which has proven to enhance the rate of denitrogenation.
This purge of nitrogen from the body means less risk of bubbles
forming during the typical 9 to 12-hour missions that U-2 pilots fly.
Of course they continue to breathe pure oxygen during the flight as well.
But back to Kevin, who now we know was experiencing symptoms of severe decompression
sickness. Of course he didn’t know it at the time. But things took a sharp turn when he suddenly
vomited inside his sealed helmet. Not only could he not see anymore, but the small holes that bring
oxygen into his helmet were also clogged. He had no choice but to open the visor on his helmet,
in an attempt to wipe off all the … goo. But with the helmet open, he was breathing air that
was pressurized to only 29,000 feet, which has nearly no oxygen in it. This was Kevin’s Everest.
With his eyesight beginning to fade, colors turned black and white,
and in his words “none of it made any sense anymore anyway.” He knew something
was terribly wrong and he finally reached out to his home base in Beale air force base for help.
It didn’t take long for the team at the air force base to realize how severe
Kevin’s situation was. He had forgotten how to use the onboard computer system and couldn’t
remember how to punch in the necessary data into the autopilot to get himself back home.
To further complicate things, Kevin was flying near less-than-friendly countries,
where an out-of-control U-2 plane could pose a serious problem.
The only option was to get him to land at an air base in a Mideast nation; the name of the country
is still classified. With some difficulty, the home base was able to guide Kevin to at
least point his aircraft in the right direction, while he was slippin in and out of consciousness.
For the final hour, two fighter jets from the host nation flew out to accompany the U-2 plane,
to show him the way. It is reported that at times, Kevin was flying within a few
feet from the ground, but somehow, he was able to safely land the airplane.
Now let me help you understand why this is nothing short of a miracle.
Not only a half-conscious, oxygen-deprived pilot dealing with a severe case of decompression
sickness was able to fly for 6 hours back to base, but he landed center line with the wings level.
See, even on a good day, landing a U-2 plane is a complicated and challenging task. As the
U-2 approaches for landing after a very long flight, another pilot follows the airplane in
a chase vehicle, communicating the necessary information to help them land. On top of that,
the U-2 only has 2 sets of wheels, placed inline, like a bicycle. With a wingspan of over 100 feet,
an imperfect landing could mean tipping to one side or the other.
Upon landing, Kevin was quickly transferred to seek medical help. Examinations showed that he
has suffered from a "full frontal lobe attack." The nitrogen bubbles had formed in his brain,
impeding his ability to function. Even though he recovered, to an extent that he went back
to flying the U-2 only after 6 months, he was permanently grounded shortly after.
It is interesting to note that until 2002, no cases of decompression sickness severe enough
to hinder U-2 operations had been reported. But between 2002 and 2009, there were 16 confirmed
severe cases. Nine of the pilots who experienced serious symptoms reported long-lasting or
permanent brain damage, and one of them was Kevin. To investigate this sudden increase, a study was
published in 2011 which analyzed 40 years of the military’s medical records. The study identified
3 major factors for the increase in cases: First, U-2 pilots were flying more often;
122 percent more sorties than they did during the Cold War. Second, they were flying longer missions
with each sortie. During the Cold War, most flights lasted less than eight hours, but now,
they could last up to 12 hours. Both of these factors meant more frequent and longer exposure
to environments that can cause decompression sickness. And finally, the type of missions had
changed. Unlike Cold War reconnaissance missions, in the 2000s, the ground combat support missions
in Afghanistan required pilots to do more things; from inputting navigational data, to adjusting
sensors. This may seem minor, but the study showed that at those high altitudes, any motion as simple
as raising an arm to flip a switch, can greatly increase the risk of decompression sickness.
Once the US Air Force became aware of this problem, they handled it with CARE.
The Cabin Altitude Reduction Effort, or CARE was the program that implemented the necessary changes
to the U-2 airplanes to almost double the cabin pressure. This means the apparent altitude in the
cockpit was dropped from 29,000 feet to 15,000 feet. Basically they went from the top of mount
Everest, to below the base camps . According to the Air Force, no severe cases of decompression
sickness have been reported since. But the thing is, pilots place considerable pressure on
themselves to complete their missions, where they sometimes subjugate their personal safety to the
needs of the mission, and so not all instances of decompression sickness may be reported.
To sign up for Ground News, check out the link in the description.