Pilot Physiology Model in AH2

[Crumpp]

I understand that GScholtz.  Yes you will lose vision.  There is not that much lag time nor is that lag time of any real value.  It's not like you lose vision and can still function.   Remember it takes O2 to work your muscles.  The more O2 deprived they are the weaker they become until they no longer function as a unit (spasm).  Your brain is the biggest O2 user in your body.  Your vision goes your body is in the hurt locker already.  Your other systems are not functioning properly and severly degraded at the least.

However, some people might think they can still function.  I've seen guys in the chamber convulsing and when they regain their faculties claim they were reaching for the "green apple" get O2 and were completely in control.  Only when they see the films do they believe the instructors.  In their minds they where fully functional but the reality was very different.   The whole point of taking guys to that limit is so they can dispell the myth they will be able to "stave it off" and can identify their particular symptoms.   I immediately regained conscieness each time I've passed out.  Being consciencous and having control are two different things.  I was very aware of what was going on around me.  I just couldn't figure out why my body wouldn't respond.  In less than 2 minutes you will recover completely.  

    There are many symptoms of hypoxia (GLOC).  Some people are effected by some of the symptoms more than others.  EVERYONE is effected though when the machine runs out of O2 enough to lose vision.  Some folks get the other symptoms as a warning.  Some recieve no warning at all, the lights just go out.  I feel really euphoric for a split second.  Then the TV shuts off, just like in AH, til I have nothing but a small white dot center sceen that fades to black.   Hitech definately got part right, at least for me.  Once that TV gets about 3/4 of the way shut off, it's all over but the crying.  
Good fighter pilots will ride that Grey line but closer they get to total blackness the greater their body is effected.  If the screen goes all black your not flying that plane anymore, it is flying you.

Crumpp

[GScholz]

Yes you can lose vision and still function. It is not like your whole body is losing its supply of oxygenated blood, your arms and legs will work perfectly. It's just that the heart is having problems pumping blood up to your head because of the increased gravity. And while the brain is the biggest consumer of oxygen, the eyes are more quickly affected by lack of oxygen. In a perfectly relaxed state it is possible to pull just enough Gs to lose vision, but never lose consciousness.

[Crumpp]

We have an Air Force Physiologist assigned to my unit and their is an AFB less than 15 minutes from my house.  I'll swing into the F16 squadron and ask thier flight med this week.  I bet you can go a long time with the tunnel vision "grey out" but as soon as your entire vision goes black your ability to function goes too.

Crumpp

[DipStick]

Originally posted by GScholz
In a perfectly relaxed state it is possible to pull just enough Gs to lose vision, but never lose consciousness.

I'm sure a real WWII pilot fighting for his life over enemy territory with an ace on his 6, pulling enough Gs to black out ... was perfectly relaxed.  

[guttboy]

Crumpp,

Not to be technical but there are many types of Hypoxia....GLOC....can fall under that category.  (So folks that dont fly or know what we are speaking of dont get too confused.)

You can function when you cant see.  Bottom line.  Period dot. (I am referring to a GLOC blackout scenario...NOT a hyperbaric scenario).

If you are saying that you cant then you are very mistaken.

Now...does it take a toll on you YES!  Anyone who says it doesnt is kidding themselves.

If you are referring to the altitude chamber there is a significant difference between g induced blackouts and blackouts due to pure lack of O2.  

When I "ride" the chamber you do the two step profile where you go up...do the symptoms then take you to the "rapid D" arena.  Works good...But here is where the disconnect between GLOC and blackout from lack of O2 in the chamber works.

In the chamber your blood supply has less O2 in it to work with due to the lower partial pressures of O2 at higher altitudes.  This does NOT go back into the bloodstream in a rapid fashion...it takes time to be brought in  to the lungs then travel the body.

In a GLOC situation, however, the blood may be perfectly saturated with O2.  The problem in this case is that the blood, fully oxygenated, cant make it to the brain.  It is still oxygenated but just cant make it there.  (hence use of straining maneuvers/g suits to keep blood up!).

When the onset of g's occurs...the blood tends to pool in the lower extremeties..hence the strain/suit.  If you "ride the tunnel" you are still recieving blood/O2 to the brain just in a diminshed capacity.  If you continue...one of the first things to go is your vision.  You are still functional and you can still maneuver...what you have to do is release the g's and then the heart/strain/suit can get the blood back to the brain.  THIS IS FULLY OXYGENATED!  Voila'  back to normal...well still strained but enough to fly.

In a hypoxic situation due to low oxygen levels in the blood....hyperbaric chamber ride example...it takes time for that blood to be fully oxygenated and circulated.

So Crumpp....there is a difference between the two instances of blacking out.  Same underlying principles (lack of O2 to the brain) however the mechanism is different and that is why you see a difference in response times to becoming "lucid" so to speak.\

Regards...

[guttboy]

Crumpp,

What base are you living near...I live in Albuquerque and am stationed at Kirtland AFB.  Been stationed at Hurlburt Field FL and Kadena AB Okinawa as well.

Regards...

[Crumpp]

I'm Army not AF.  I was stationed at Torii on Oki and lived on Kadena though.  Great place.  

I'm next to Pope now.

I agree that the mechanism for how the hypoxia is induced to the tissues is different in GLOC.  However the end result is the same.  You lose vision I bet you will lose control.  Your tissues are hypoxic enough to no longer function properly, hence you lose vision.  

One point that I do agree on.  Your recovery would be quicker from GLOC due to the O2 saturated blood already in your system.

Crumpp

[Crumpp]

Ok,

Here is some links and the facts on this subject:

Yes you can "blackout" without losing consciousness.  However you might as well be unconscious because your useful actions are very limited.  Your period of unconsciousness (medical) is very short but the disorientation last up to three minutes (average is like 37 seconds).  It takes a few seconds according to our Doc to recover from the disorientation of a "blackout" too.

Depending on the type of G's experienced and how they Onset determines the length of time between grey zone and actual blackout. From what I understand a pilot does not actually stay in the "grey zone" but rather hits it and backs off, then hits it again.  Even in the grey zone your are not very useful as a thinking man.

GLOC is even more disorienting than normal Hypoxia. One of the big factors is there are a number of "illusions" that occur in the grey zone and above.  This is due to the fluid pooling in the Semi-circular canals throwing off the brain's reference to up and down.  Pilots can no longer see or interpet the insturments and enters one of several fatal scenarios.  

Remember in this data the pilots had modern G-suits, AGSP, and Combat Edge kits.  All are designed to push a pilots G tolerance.  In 1939 many AF's believed the age of dogfighting was over.  Pilots could not stand the G forces required in a "Modern, low-wing, metal skin fighter".

-----------------------------------------------------------------------------------

Simo Siitonen, M.D.

+ Gz-forces in F-18 Hornet

In operational use F-18 Hornet has G-onset rate up to + 9 Gz. Contrary to previous high-performance aircraft of Finnish Air Force (FAF) Hornet can also maintain that Gz level for some time. This will result to physiological problems in form of circulation disturbance. Blood will be packed in lower body and eye-level blood pressure drops dramatically. After 5 seconds grey out occurs and if Gz load remains black out will appear shortly after grey out. A pilot loses his/her consciousness if Gz load is not rapidly decreased. Gz-force induced loss of consciousness (G-LOC) is the deadliest enemy of a fighter pilot if we think military flying from the aerospace physiology aspect.
Eye-level blood pressure drops 22 mmHg for every Gz. Normally eye-level blood pressure is about 100 mmHg, but during + 4 Gz exposure eye-level blood pressure has dropped to 12 mmHg, if a pilot is not using any G-protection. Without G-protection average pilot can handle + 4 Gz force without problems.
During WW II G-suit was introduced to better pilots G-tolerance. Together with L1/M1 counter maneuvers (muscle contractions and intrathoracic pressure increasement) G-suit will increase G-tolerance to + 8 Gz for short time. After + 2 Gz in modern fighters G-suit pressure will increase 8.6-10 kPa for every G, but maximum pressure is 69 kPa. Full cover G-suit (ML Lifeguard) of Finnish F-18 Hornet has 45 % larger air bladders than previously used G-suits of FAF. This means that G-tolerance has increased from + 1.5 Gz (old G-suit) to + 3 Gz (full cover G-suit) because of G-suit.
Pilots use G-suits because: 1) G-suit increases blood vessel resistance in lower body leading to increased blood pressure, 2) G-suit induced intra-abdominal pressure elevates heart 3 cm and shortens heart-brain distance and 3) venous blood is not situated in lower body and heart has enough venous blood in use to pump it to brain.
Pentti Kuronen, M.D. (Chief Flight Surgeon of FAF) led an evaluation team which selected pressure breathing system (ML Lifeguard) for F-18 Hornet of FAF. Also pressure vest, regulator and on-board oxygen generation system (OBOGS) were included in this system. Increased intra-thoracic pressure made by pressure breathing system increases G-tolerance about + 2 Gz. This way also risk of G-LOC decreases significantly.
Why fighter pilots and flight surgeons want to avoid G-LOC ? During G-LOC absolute incapacitation lasts 12 to 20 seconds but relative incapacitation can take more than 3 minutes. During those minutes anything can happen ! In US Air Force 12 % of the fighter pilots had experienced G-LOC. The same rate in US Navy was 14 %. Based on centrifuge experiences flight surgeons know that 50 % of G-LOC pilots do not remember their G-LOC experience. This means that one fourth of fighter pilots in USA have been on the edge at least once during their career.
Modern technology together with understanding of aerospace physiology has give fighter pilots tools to fight not only against the enemy, but also against themselves in high Gz environment.
Modified by Tuomo Leino, M.D.

Research on the degree of incapacitation caused by GLOC has indicated that there is an average total incapacitation (unconsciousness) time of 15 seconds followed by a period of relative incapacitation (confusion and disorientation) of 12 to 15 seconds, resulting in a total time of incapacitation of between 24 and 37 seconds (14). Research is now focusing on ways to both prevent the GLOC episode and to shorten the periods of incapacitation.

http://www.sci.fi/~fta/physiolo.htm

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This one is extremely technical.  You need hard data HiTech, well here it is...

http://wwwsam.brooks.af.mil/af/files/fsguide/HTML/Chapter_04.html

Research on the degree of incapacitation caused by GLOC has indicated that there is an average total incapacitation (unconsciousness) time of 15 seconds followed by a period of relative incapacitation (confusion and disorientation) of 12 to 15 seconds, resulting in a total time of incapacitation of between 24 and 37 seconds (14). Research is now focusing on ways to both prevent the GLOC episode and to shorten the periods of incapacitation.

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Bottom Line - You can ride the grey but if you hit the black bad things start to happen.  Since Hitech can't reach through the screen and shake you into disorientation then the relaxation of the controls for a second or two is a good way to "sim" pilot disorientation, Or better yet IMO, the "wounded pilot" head movement along with a short period of control dampening.

Crumpp

[guttboy]

Depending on the type of G's experienced and how they Onset determines the length of time between grey zone and actual blackout. From what I understand a pilot does not actually stay in the "grey zone" but rather hits it and backs off, then hits it again. Even in the grey zone your are not very useful as a thinking man.

Crumpp,

Exactly....Onset is the big key....look at it this way....if you were flying and riding the "grey zone" for say 15 minutes (pretty ridiculous) in a constant 5g environ you would be an utter mess for the most part.

Instantaneous onset to the same point would have less of an effect on your body.

What does occur is like I mentioned before...you can and do ride that edge.

If you do lose sight altogether (although not wise and for only fractions of a second) you must back off....you still are in control of your acft and thus back off....if you do not then thats another story.

Yes you can "blackout" without losing consciousness. However you might as well be unconscious because your useful actions are very limited. Your period of unconsciousness (medical) is very short but the disorientation last up to three minutes (average is like 37 seconds). It takes a few seconds according to our Doc to recover from the disorientation of a "blackout" too.

Crumpp...I agree with what your doc is saying, however, disorientation can last up to 3 min.  It can...It does not always however and it is an individual thing.  

This is NOT something that I would advocate (Blacking out) Crumpp....I am not stating that by flying around without vision for any more than fractions of a second would be effective or safe...what I am saying, because it happens, is you CAN lose vision momentarily (aka...bumping the edge of vision loss) and still not be unconscious.

Another thought....Perhaps...and this is most likely the case...when I have experienced vision loss it may not have been right at the point of total loss....that can also explain why I havent funky chickened...LOL....

Crumpp I fly for a living and went back into the closet....I was  biology major at the USAF Academy as well and I pulled out my Fundamentals of Aerospace Medicine book....to quote....

"In typical +G sub z exposure approaching a subject blackout tolerance, the individual will normally have clear vision for about 2 to 4 seconds after reaching peak G (onset rate = 1 G/sec), then peripheral vision will fail, with only a cone of central vision available for reading instruments.  A second or so later this will fail, and total blackout will occur, In about 2 more seconds, vision will suddenly return as compensatory reflexes  are initiated to cause an increase in head-level blood pressure and an rise in heart rate.  From that point to the end of the G exposure, vision will remain clear.  The G level at which these events occur is defined as a person's blackout threshold."

Now with all that being said...it is a FINE line...one that should not be pushed to the extreme.  I think that we are talking about the same thing in but the nuances are slight.

Good reads in your post.....And I agree with everything that is said there...we get the same training and education everytime we do the Hyperbaric chamber.


On another note....cool you were at Torii Station?  I used to get all my dive gear there!!!  Were you with the 1st of the 1st?  I miss the island alot!  Especially the diving out there...not much of that here at Kirtland AFB I can tell you that!

Regards my friend....great debate here

[Crumpp]

Hitech,
Let me clarify my position on the Current Model.  It's a great base and with some minor changes could simulate the disorientation of flying at the edge for someone sitting at a computer better.  

1.  If a pilot stays in the Grey Zone - no change to the current model.

2.  If a pilots takes it to the "all black" screen - The countdown to unconsciousness starts and a number of cumlative effects begin to happen.

      First time - Pilot gets a "wounded pilot" head shake as soon as vision returns.

      Subsequent times - Head shake AND control dampening with the period of dampening increasing the more times you enter the black.

       
IF Unconsciousness is reached the pilot has bought the 37 seconds of incapcitation.  Some of it in total blackness and some it in the frustration of flying at whatever control input when consciousness was lost.

The "clock" gets reset by a set time of flying at 1 G regaining a pilots "composure".

Perk points could be spent in Tour of Duty representing Physical training, Anti-G position training, and the skill your pilot has to apply them.  These would serve to lessen the effects.

Crumpp

[guttboy]

Crumpp,

I would have to agree with you on the modeling....that would be a good feature for TOD...for the MA (CLASSIC)...I think HiTech would get a lot of complaints from folks that fly in the "black" realm.

I dont go 100% black in the game...just I guess force of habit of "that will kill you".....but I like your suggestion.

Regards:)

[Crumpp]

Yes,
I was with 1/1.  Jason and Twins (Torii Locker), Gary Haglan (Kadena Locker) are all real good friends of mine.  I taught diving in my off time through MWR. I loved Asia and Speak Vietnamese fluently.  My regional orientation has changed, but I still miss that part of the world.

Yeah I think the current model has no real penalties for hitting the black excessively.  Pilots should fly the Grey but strive not to hit the black. Real pilots do this and we should too.

Great discussion!  Thanks for keeping me straight.

Crumpp

[SlapShot]

Originally posted by hitech
the funky chicken is modeld guttboy.

There are 2 modes of "Black out" modeled.

1. Where you don't see.
2. Where you are doing the funcky chicken.

Fatigue will build everytime you are fully blacked out "cant see".

Once a threshhold is reached you will be made uncionsious, the stick is automaticly released,the screen will still be black, and your current flight path is in a stick nutetral path.


HiTech

Great stuff Crumpp and guttboy !!!

I can testify to experiencing the "funky chicken" in AH I. Both times I was in a P-38 pulling massive multiple Gs.

I went into blackout, released the stick expecting to come out of it and oooooooh noooooo. I was in total blackout for what seemed like hours.

[guttboy]

Great discussion Crumpp....I like it when the boards (and channel 1...LOL) stay good context and not trash talking.

I loved Kadena....I was with the 353rd SOG out there stationed with the 17th Special Operations Squadron flying MC130s....Flew AC130s before that at Hurlburt.

One of the things I miss the most is the people on Okinawa...they were some of the nicest people in the world.  What was your favorite dive spot there.

I had a couple...I really liked Devils Cove...found some WWII ammunition that I have at home now (and it was close to the house and easy access through that little park when the surf was insane).

I had another we called "dead Cat Cut" because we found a dead cat on the walk down....it was on the north side of the peninsula that Bolo Pt was on.  Deep dive good fish.

Finally my fav of all time spot is horseshoe beach just down the shore from Toilet bowl....GREAT corals fish and pretty quiet as far as other divers go!

I managed to log well over 100 dives a year with pulling tdy 220+ per year I was stationed there...VERY UNDERSTANDING WIFE!!!!

What you doing at Pope now?

Take care cya in the air...What country and callsign you use?

Regards:)

[Crumpp]

Man you are bring back some memories!! I loved Meida Point for first time divers.  They loved the cave plus it was a great place to get students out of the water if things got rough.  Also it was cool for students to be totally surrounded by that huge school of Angel fish that camped off the tower there in the summer.

My favourite ones where on the end of the island past Naha.  We had "pipeline" and the very end of the island.  Wicked currents but I almost always saw big sea life.  Rays, Sharks, and sea turtles mostly with a few octopus's thrown in the mix.

Ie Shima Island was great too. My favourite place for Spear Fishing. Since I had a boat license for our 28 foot Boston Whaler, the command let us use it on the weekends.  We just had to top it off before we brought it back to the Maritime Operations Facility.  

I was on ODA 115 (Combat Diver) while in Oki.  Yeah I miss the folks over there too.

I'm at Bragg now.

I fly LW under the nick "Crumpp" in AH mostly in the CT.  Occasionally I'll show up as a "bish" in the MA.  MA really isn't my cup of tea.

BTW - Great diving in my AO if you can get this way.

Take Care! If your still in the community I'll start stickin my head the cockpit askin "what do you think of the Pilot physiology model in AH?"  LOL
Crumpp