U-2 pilots suffer brain damage

U-2 pilots suffer brain damage

Aviators piloting aircraft at very high altitudes for the military have "significantly more" brain lesions known as white matter hyperintensities, US Air Force medical researchers have found through MRI scanning.

It flies at altitudes above about 69,000 feet (above 21,000 meters) and maintains a cabin altitude - the altitude equivalent kept inside the cockpit or cabin of an aircraft - of between 28,000 and 30,000 feet.

What is missing here is the effective altitude when wearing the pressure suit. I certainly hope the pilots are not flying at equivalent 28kft. That is well above the point where some people have altitude sickness. The altitude is not a hard number. Probably it depends how you measure the distress of the individual. I have been at 8000ft with a number of people and nobody ever complained.

reply to post by gariac


We always pressurized our aircraft to 8000 feet. Hypoxia starts to kick in at 18,000 feet. But that story does seem wrong. I don't think that they had a cabin altitude that high. After all they could take their masks off whenever they want to eat grub. So there's no way it was that high.

So,have they sat all these pilots down and said 'sorry guys, but your risks of a stroke and / or dementia just went through the roof'?

Well, that's not something I'd like to read on my annual fitness report - I hope the views from up there were worth the memories - cherish them whilst you still can guys

That is interesting. I wonder if there is a solution to the problem without having to suit all up.

I stand corrected. Apparently they pressurize the cockpit up to around 30000 or so during high altitude flights. Guess they don't eat...

Yeah they do eat, they have a little space meal in a weird bag and an adaptor from their helmet. Squeeze it up and nom nom nom.

reply to post by gariac

Hi, gariac.

You said:

I have been at 8000ft with a number of people and nobody ever complained.

No problem.

I was at 9500' for a good while, in a RV-7 and I did not feel anything special !!
We where back from Oshkosh to Montreal. WHAT A 2007 summer SHOW it was !! B-)

I hope/guess I was not in danger, knowing the regulations about flying 10,000' or FL0100
and over, for short times, without a mask.

Blue skies.

reply to post by C-JEAN


The threshold is 8kft, but it isn't like this is a binary effect. Around 10kft, some people start to feel the effects. I've done about 11kft and never noticed anything. But the deal is with instrumentation, you can nearly always find some effect for just about anything.

There is much nonsense on the internet about altitude sickness. Very little has research to back it up. I had to laugh about one of those link bait farms that suggested hiking no more than 1000ft a day. Good luck doing anything at that rate. About the only source I trust is the US Marine mountain warfare center. They have papers backed up with medical research.

A lot of lighters won't work over 10kft. Using a turboflane with Primus all-season gas. Brunton makes an adapter so you can go from the can to a lighter. Those esbit fuel tabs are really hard to get going with just matches.

Originally posted by gariac
U-2 pilots suffer brain damage

Aviators piloting aircraft at very high altitudes for the military have "significantly more" brain lesions known as white matter hyperintensities, US Air Force medical researchers have found through MRI scanning.

It flies at altitudes above about 69,000 feet (above 21,000 meters) and maintains a cabin altitude - the altitude equivalent kept inside the cockpit or cabin of an aircraft - of between 28,000 and 30,000 feet.

What is missing here is the effective altitude when wearing the pressure suit. I certainly hope the pilots are not flying at equivalent 28kft. That is well above the point where some people have altitude sickness. The altitude is not a hard number. Probably it depends how you measure the distress of the individual. I have been at 8000ft with a number of people and nobody ever complained.

Or it could be an effect of cosmic radiation. Though the heart does pump blood into the brain in a way that circulates oxygenated blood from the centre of the brain to the outer surface of the brain. So these lesions should be closer to the arteries. If they were on the outer surface, or all throughout the brain that would be more due to radiation.

U-2 pilots suffer most of the same symptoms that they're finding in F-22 pilots (minus the Raptor cough), but they go so long between flights that their body has a chance to recover from it for the most part.

Boomer, they have a special tube on Theo helmet near the corner of their mouth, with a flapper valve in it. Their food is liquified in tubes that fit through there and into their mouth.

stormcell

Or it could be an effect of cosmic radiation.

This was my first impression also.

Can't see how it would be related to altitude, or you'd see Everest Sherpas having similar probs

reply to post by Puffnstuff


It's most likely related to the pure oxygen that they use. Pure oxygen has some interesting effects on the brain, and that's what U-2 pilots breathe in their suits.

"When the children inhaled pure oxygen, their breathing quickened, resulting in the rapid exhalation of carbon dioxide from their bodies," said study co-author Paul Macey, a UCLA associate researcher in neurobiology. "The drop in carbon dioxide narrowed their blood vessels, preventing oxygen from reaching tissue in the brain and heart."

That's when something surprising happened on the MRI scan. Three brain structures suddenly lit up: the hippocampus, which helps control blood pressure; the cingulate cortex, which regulates pain perception and blood pressure; and the insula, which monitors physical and emotional stress.

All this activity awakened the hypothalamus, which regulates heart rate and hormonal outflow. Activation of the hypothalamus triggered a cascade of harmful reactions and released chemicals that can injure the brain and heart over time.

"Several brain areas responded to 100 percent oxygen by kicking the hypothalamus into overdrive," explained Harper. "The hypothalamus overreacted by dumping a massive flood of hormones and neurotransmitters into the bloodstream. These chemicals interfere with the heart's ability to pump blood and deliver oxygen — the opposite effect you want when you're trying to resuscitate someone."

newsroom.ucla.edu...

Under the CARE program, they are reinforcing the cockpit structure, and lowering the pressure altitude to 15,000 feet. The CARE program should eliminate DCS symptoms. It took 33 days to do one airframe, and there were as many as four airframes in at any given time.

Each aircraft underwent work to reinforce the airframe, replace valves, change the bleed air system logic, and alter the cockpit controls.

www.beale.af.mil...