Forum: Technology

Salute all!

Loss of conciousness due to gees has come up on the F-20 thread. So let's put some stuff out there......

First of all, if you pull hard enuf, long enuf YOU WILL LOSE conciousness. But in previous jets it was gradual. First tunnel vision, then gray, then black, then.......

The physiology lecture we had ran something like this:

you can pull many, many gee's for a second if you ease off right then and were clenched up at beginning (chest tight, neck tight, etc.).
if you pulled many, many gee's real quick and were not all tight, then you bypassed the traditional cues and went straight to the "blackout". So the F-15, 16 and 18 provided us the oppo to test this 'theory'
bad thing about going from 'all is well' to G-LOC was it took you 20-30 seconds to even be coherent. maybe a minute to be close to normal.

You knew this was coming..... I was backseat of the third troop that demonstrated this phenomena.

First one was also in my flight. Names private, but here goes. The troop was in front seat with 'edderds' and we were a three-ship. My stud (I was in a family model) was outta the fight and gaining energy/alt. Suddenly, this plane goes into a very tight, high AOA spiral and edderd let's out a 'whahoo!' over the radio. Then 'knock it off'. He recovers the jet and then tells us he can't talk to the stud in front seat. Turns out the stud's g-suit was disconnected. Also turns out he reefed the jet into a high-gee pull very quickly while looking up. So we come home and debrief and all make sure our g-suit is connected real good from then on.

Next one was in some TV specials. Rooster was in back seat and showed us the tape just after he landed (long before PBS, ABC, Discovery or anyone else got it). Great tape, and the stud was rambling for 20 seconds, but not able to do squat. He would have been a smoking hole except for the IP.

About a week later I am in a family model and Joe Baggodonuts is looking up at the bandit converting on him. We are not too nose low, maybe 20 degrees, then he yanks real hard. About a second later the gees go to 1 gee or maybe a little less. I wonder why he ain't pulling. Maybe he's trying to get more smash! Then I see his head beating the canopy. 'Hey, ski! I called'. No response. So I recover the jet while calling 'knock it off'.

Ski finally talks to me. I ask him to check his g-suit. Sure enuf, it's disconnected.

There was a way to put the g-suit hose under the lap belt that helped to keep it from disconnecting. Most folks weren't aware of that technique. Very soon, we got better connections and so forth. Also, the family model front seat seemed a bit further forward from the g-suit connection. Who cares, they fixed THAT problem.

Our physiological training got better and we only lost another few troops to gee-loc. Marathon runner - bad. Bench press, no-neck fooball player - good. Low blood pressure - bad. Short- good. Tall - bad.

End of post: We found, and the Doctors found out, that if you have a very high gee onset when 'relaxed', then you can knock yourself out in two seconds if your jet can get to 7 or 8 gees in less than a second. Older planes couldn't do that.

out,

F-16.net Sponsor

Gums, I recall reading a medical brief, might have been from the squids, that mentioned that there was also a cumulative effect of pulling Gs pos-neg-pos. It said that a certain series of events like a 3-4g positive for a few second, an unload to negative G for a few, then a positive pull to any G was an instant off-switch for the stick actuator. That sequence is what I recall from about 4-5 years ago so don't quote it as gospel. Did you ever hear of anything like that?

Kevin
The Ejection Site

I don't think so, but I ain't a Doc.

Seems to me that pushing over forces more blood to the brain, so one might actually have a better positive tolerance after negative gees.

The one guy we had a Hill that had the computers freeze up pulled something like 22 negative gees. He ejected once the plane wound up in an inverted stall/spin. Was actually back home the next day and had the two biggest black eyes you ever saw.

J. Moats supposedy ejected when negative gees got down to -3. Chute began to open just as he hit. Was about 300 feet or so when the computers froze. Another hundred feet and he would have likely made it. (we'll get a thread on the computer power failure doofer back on main board one day)

Damned good seat, as I've said before. Sure glad you and others like you kept'em working. Haven't heard of a single failure.

later,

Wow. As usual great stuff.

Whoa... holy shite, now that puts a whole new perspective on what I used to think bout pulling Gs..

Ok now for the million dollar question Gums: HOW do we train up for G-tolerance ? I've heard of dudes that didn't get to the Viper because they only managed to pull 8Gs or something like that...

Is there any way to increase the body's resistance to Gs so that you don't black out that fast (besides doing the AGSM) ? Any sports to play, any exercises to do etc ?

I'll be signing on with the Air Force as soon as I graduate from college, and I'd really appreciate any tips you got.

Salute Razor!

Ask Cylon and STBY for latest poop, but a few things we learned early in the program.

Don't train for marathons. You need your body to increase blood pressure, heart rate, etc. If you have a pulse rate of 55 during a fight, you'll have less g-tolerance
do curls, bench presses, and crunches. You need to keep the blood up in your brain. G-suit helps for lower extremities, but until they put a noose around your neck, you need to have upper body muscles and know how to use them
there are recommended techniques for breathing and contracting your muscles. Again, Cylon and STBY will have the latest poop.

Hell, I was 41 years old when I flew my last mission. Only way I could hold above 7-8 gees for over 5 seconds was to anticipate. Otherwise, I would pull for a second, take a breath at 4-5 gees, then pull again.

The young sprogs could fly at 5-6 gees for a long, long time. So could I, but I wasn't very effective. Heh heh.

later,

A couple of good articles on G-LOC and G training on the Code One website:

http://www.codeonemagazine.com/archives ... ra_92.html

http://www.codeonemagazine.com/archives ... ra_90.html

http://www.codeonemagazine.com/archives ... na_90.html

(ok, three)

For info: Transitioning from zero or negative G does make the pilot less able to cope with high positive G forces. It is recommended that after doing -G's to keep it low for at least a few seconds, before pulling to the hard stuff.

I can't remember why this is worse. Perhaps it was to do with an accelerated drain of blood from the brain. Or the fact that you should be relaxed when pushing neg G's, and you gotta be very quick to tense up before hitting the pos G's... (speculating now). I have spoken to a few high level aerobatic pilots who have advised me to be careful of this.

A few years back I used to push negative G in aeros, and as part of my guns jink. The instructors hated it, as they couldn't follow me. They also REALLY hated it if I did it whilst they were in the back seat with me !!

OK, they weren't actually IN the back seat WITH ME. Rolling Eyes

Gotta get in quick before Gums, Habu brothers or Razor closes in for the kill !!

Rogah that, thanks for the info fellas !

Cylon and STBY, you got mail ! Very Happy

And Jorgo, check your six d00d, heheheh Wink

Don't know of others that do this or not, but some of the C Eagle pukes will "warm up", do a few hard turns and pull a few g's to "get the blood flowing", before having a friendly battle.

Don't know if that is some big approved technique, but that is what an F-15 guy told me once and later read something similar in an article, and sounds like it is part of the bigger picture of overall health in the cockpit, for doing all the crazy stuff that fighter pilots do.

The warm up routine is the norm in the Aussie F/A-18 world. They normally do a couple of 180's at 4G. It seems to help.

Then again, weight lifters don't just come into the competition and try and lift 500lbs. They also warm up with lighter weights. So it makes sense.

You're gunna have to push on the stick harder than that Razor. Byeee..

Any of you gents care to comment on the newer full-body anti-G suit and PPB masks? Any good scuttlebutt you can pass along to us non-flyin' types? Question

Seems like a few years back MacAir was workin' on a new suit and mask system that would allow sustained 10 Gs for upwards of 30 seconds (not that anyone would actually WANT to be in that regime for an extended period). They spun this human lab rat up to 10 in the 'fuge and he was still able to converse the the TD, albeit with some effort given his cheeks were down 'round his shirt pockets.

Apparently they are the bee's knees, but ya gotta love being squeezed all over, and then having oxygen pressure blown into your lungs cause you can't breathe.

Guess they should make them outta latex rubber - sounds kinky !!

Ok, this board has been inactive for awhile, so I will add my two cents.

You wanna know about Combat Edge? You came to the right guy. I've prepared it for the fly boys and have used it (albeit in a ground test.) It's great. Some of the older jocks had a bit of trouble adjusting, their take being that REAL pilots don't need Combat Edge. The studs, however, took to it like ducks to water.

I'll start from your toes, and take you up to your head, as that was how I briefed pilots, when instructing them on how to use it. (BTW, when I briefed pilots on how to properly use the equipment, I would also be wearing a flight suit, and would put on my own equipment as I went along. Then I would hop in the simulator, and blow everything up like a balloon to show them what it looks like, and show proper breathing/muscle tension at high G.)

First, I would recommend making sure your boots fit SNUGLY. Not too loose, but not too tight either. Not only is this for safety, but it also ensures proper circulation (sounds silly, I know, but it is SERIOUS.)

Next, going up you have your G-suit, which everyone should be familiar with by now. The G-suit is good to have, however it can be a "Wolf in Sheep's Clothing." It's not really very good over roughly 2 to 3 G's tolerance.

Next, we come to the new equipment, Combat Edge. This is the vest that you will wear under your harness. It works separately of, but in conjunction with your G-suit. The hose that comes out of your left chest panel, will connect to the top port of your CRU-94 respirator unit (at this point, I would show them a CRU-94, and show a proper connection.)

Next, after donning the harness (which I did,) again ensure a proper connection of your G vest hose to the CRU-94. The reason, The G vest mainly works through your breathing. When the aircraft is onset with higher G forces, your breathing/straining will increase. This is what will help inflate your vest. Your oxygen mask will plug into the CRU-94 the same way (and in the same port position) as the older CRU-60 respirator. Next, we come to the 20/P mask. There are a few differences between the 20/P and the older 12/P mask (I would have an example of both to make it clearer.) First, the mask is a softer plastic, designed to custom fit to your face. Unlike the 12/P mask, the 20/P features both an inhalation (inside the mask under the hose,) and an exhalation valve, on the opposite side. This allows for you to focus your straining on the G forces, not your breathing (very crucial.)

Next, you will notice the small, black hoses that connect from your mask, to the port at the left rear of your helmet. This connects to the G bladder on the inside rear of the helmet. Once again breathing/straining actuated, it will inflate when higher G's onset, and your breathing/straining becomes more intense.

By this point in the briefing, I would have all of my own equipment on, and would sit in the sim to show them exactly how it looks starting at about the equivalent of 2 G's, all the way up to about 9 1/2 G's. I'd also wear a clear visor on my helmet, so they could get a good look at how I looked, when straining against the pressure.

Bottom line, Combat Edge is great equipment, but ultimately, it will also come down to how a pilot prepares (exercise, G warm-ups, proper straining technique) ALONG WITH proper use of the equipment that will decide a pilot's max G tolerance. I've heard that the Navy will soon be adopting their own version of Combat Edge. Hope their version works just as well as the USAF's version.