Interesting Reading

[Gyro]

 This article is kinda interesting I thought http://www.combatsim.com/htm/may99/blackout.htm


Gyro

[CptTrips]

Yeah, nice article.


> To provide high-G tolerance the designers
>tilted the seat back 30 degrees from the
>vertical and raised the heel elevation six
>inches above the Vietnam era seats. These
>modifications reduced the effective
>distance between the heart and the brain
>which increased G tolerance by about two
>G's. By doing this they effectively gave
>the F-16 driver an edge over any other
>aircraft.

> Furthermore, since that time systems have
>been added such as "Combat Edge." This
>system consists of a "Positive Pressure
>Breathing" oxygen regulator which forces
>air into the lungs to assist oxygen intake
>during straining maneuvers, coupled with a
>vest that limits how far your chest will
>expand (we don’t want to blow up like a
>balloon now do we?) Also, a few years back
>engineers increased the air flow output in
>the G suit to aid in response time and
>obtain near instantaneous inflation.


I assume, since they took the trouble to implement these extensive measures, that GLOC was infact a problem in earlier generation aircraft or they would not have bothered.  Not really in WWI, but certainly by WWII.  At this point air frames and power plants evolved to the point where they could generate and sustain g-loads in excess of what the human occupant could.

And of course, 1942 era pilots did not have the benefit of 30 deg inclined seats, positive pressure oxygen regulators, and G-suits.  They didn't know anything about anti-G strain maneuvers.  GLOC was in fact a real concern the ACM of that era.  To try and produce a faithful representation of WWII era combat and leave out GLOC would be like modeling WWI Camels and DR. 1 without including the strong engine torque that was their hallmark characteristic. ;>

In Boyington's bio, he talks about accidentally learning that tightening his neck muscles in high g maneuvers gave him a few seconds edge against pilots who didn't. (i.e. THEY BLACKED OUT BEFORE HIM OR HAD TO START UNLOADING TO AVOID IT). I read about one German pilot who to escape a pursueing Spit, pushed over into a high negative g dive which the spit could not follow (gravity fed carb).  As he sustained the push over he completely red'd out.  When he finally made it back to his base and got out of his plane, people looked at him like he had grown horns.  Until someone lead him over to a nearby mirror and he could see that his eyesballs were blood red from all the capularies bursting.

Look, you got big, fast planes.  When you go making radical changes in the velocity vector you're gonna generate alota g's.  Mother nature just never designed that 8 lbs of wet sponge in your noggin to operate under those conditions.  Now is the onset gloc in the current modeling too soon, should the effect be more gradual, should it be influenced by how quick the g's are loaded or more from cummulative effect; those are all factors that will be tweaked in the coming weeks.(Christ its only B day + 4!)

But anyone (not necessarily Gyro),  who claimes that modeling GLOC in a WWII fighter sim somehow makes it less realistic, is either uninformed, or is being disengenous.  Or both.

Regards,
Wab

[Bohica]

UMM, I would be very carefull what you say.

I am a pilot and have experienced GLOC and I can tell you where it occurs, and its higher than 4.5 Gs.  If you have ridden Lightning Loops or some other roller coaster that loops they are usually designed somewhere around 5 G for front or back car as they go through the loop.  Did you black out last time you were on one?

There are also 2 types of G loading, Instant and progressive.  Instant loads of 9gs and its lights out for the most part.  To fly an F-16 you have to be G rated because of that.  It was one of the first aircraft that could INSTANTLY put 9Gs on you.

The WWII Pilots were capable of blacking them selves out if they were in a high energy state.  ABsolutely.  They were able to load alot more than 4 or five Gs on the airframes to do it.  

However my personal tolerance is up around 6 Gs with no pressure suites and minimal straining.  If I were to practice the straining manevers that the F-16 pilots practice and were extremely proficient at it, I could proably add one more G to it, for a short while.  But 7+ gs definately requires the pressures suits, in reality anything above 6 does, GLOC is BAD!  Often when you come out of it, you will spasm like an epileptic.  Some call it the funky chicken dance...

Now I am 5'7" and a blood pressure of about 120 over 80.  (High blood pressure is good for this sort of thing believe it or not, and guys that are in great shape have more trouble)  Taller guys also have more trouble, where shorter guys with higher blood pressure would have an advantage over me.   The German Pilots took Dexedrine to stay awake, but it also raises the blood pressure.  That and the seat position of the ME109 probably gave them an advantage.

Ideally I think women have a greater G tolerance when using Gsuites because their CG is lower, so there is more blood to be squeezed by a pressure suite, and they tend to be shorter.  Biology is in THEIR favor on this one.

As fly by wire takes off, and strength is less and less an issue, I expect to start seeing women win the fighter trophies... The only reason they haven't done it so far is they haven't been flying combat aircraft long enough.  But wait, Next five years or so you will start to see it.  

Oh and everyone knows who Patty Wagstaff is right?



------------------
Bohica
900th Jaguars

[CptTrips]

>UMM, I would be very carefull what you say.

(best Beavis voice) Are you threatening me?  I am the great Cornholelio!

>I am a pilot and have experienced GLOC and
>I can tell you where it occurs, and its
>higher than 4.5 Gs.
...
>There are also 2 types of G loading,
>Instant and progressive.

>The WWII Pilots were capable of blacking
>them selves out if they were in a high
>energy state. ABsolutely. They were able to
>load alot more than 4 or five Gs on the
>airframes to do it.


OK, I'll have to quote myself. :> (you made me do it. ;> )

>Now is the onset gloc in the current
>modeling too soon, should the effect be
>more gradual, should it be influenced by
>how quick the g's are loaded or more from
>cummulative effect; those are all factors
>that will be tweaked in the coming
>weeks.(Christ its only B day + 4!)

So, yeah.  The is some threshold, well within the envelope of WWII that makes you go nighty-night.  And yeah, it may need to be tweaked.  But gloc is perfectly reasonable to model if you pass that magic number.  Alot of the arguments I've seen (on other bbs)is that its not realistic because you can't feel the g's to warn you.  True, but that can't be helped.  They do give you an acceleramator to monitor your load.  I think the alternative of leaving out gloc at all would be much worse.

$0.02 I'll bill you later. ;>

Regards,
Wab

[Bullethead]

>>>>>>>>. The is some threshold, well within the envelope of WWII that makes you go nighty-night. And yeah, it may need to be tweaked. <<<<<<<<<<

The suddenness of blacking out in AH is a subject of lively debate over in my squad bbs  .

Personally, I have no problem with the current modeling.  I don't start getting any tunnel vision at all until I pull about 4.5 Gs and then only around the edges.  I hardly ever get the serious "gunsight only" tunnel and have never blacked out totally in a fight online.  I believe this is because I'm more gentle with the stick than most of my squaddies.  I've experimented with yanking the stick in AH and that does make blackouts pretty total and sudden.  

So the game does in fact model the difference between instant and progressive G loading.  If you do it progressively (and very gently), it's no big deal.  The question then is whether the progressive loading is too touchy as modeled now.  

As of yet, I don't think we have sufficient data to go on because none of us are as used to flying AH as we are "Brand W" and "Brand A"--we still have to train our wrists to AH's flight model.  Also, I doubt anybody's got their stick scaling optimized for AH yet, because the flight model seems a bit different from "Brand W."  Once we get a better feel for AH and then scale our sticks, however, I believe we'll find the onset of blackout is pretty close to right as it stands now.  After all, I'm not having trouble with it and figure that scaling my stick will allow me to be more hamfisted than I fly now.

-Bullethead <CAF>

[Windle]

We could use the 'D' key for Dexedrine ingestion. I don't think it's being used for anything else.  

 

------------------
Lt. Jg. Windle
VF-17 'The Jolly Rogers' 8X
  Skychrgr@aol.com  

[Jochen]

 

To provide high-G tolerance the designers tilted the seat back 30 degrees from the vertical and raised the heel elevation six inches above the Vietnam era seats. These modifications reduced the effective distance between the heart and the brain which increased G tolerance by about two G's. By doing this they effectively gave the F-16 driver an edge over any other aircraft.

Old news  

Fw 190 had higher heel elevation than other fighters of its era and it was credited to give pilot a edge on fast and hard G turns.

(Fw 190 in combat by Alfred Price)

------------------
Oblt. jochen 'Stern von Afrika' 2./ Jagdgeschwader 27 'Afrika'

[Vermillion]

 

If you have ridden Lightning Loops or some other roller coaster that loops they are usually designed somewhere around 5 G for front or back car as they go through the loop. Did you black out last time you were on one?

Are you sure about that Bohica? It was my understanding that even the most powerful rollercoasters don't pull more than 3 G's (contrary to many hyped stories and advertising for publicity), and that even then the onset is very gentle and very brief so the effect is mild.

I am not normally a pilot but I did take an aerobatic flight in an AT-6 Texan with Warbirds Adventures, down in Kissimee FL (its great btw, well worth the money). We pulled quite a few 4.5-5 G manuevers, and I can guarantee you that I have never experienced anything close on a rollercoaster. And I have rode the biggest and baddest coasters in the country.

Now for me, as long as I was prepared and used the "grunt" technique the pilot taught me, I didn't have the slightest problem with blacking out or geting tunnel vision. But once I was rubbernecking at the scenery and was unprepared, we pulled a hard cuban 8 and I got the "tunnel effect" we see in AH.

While discussing this with my pilot, he told me I had a high tolerance for G's, and that typically most passengers have many more problems than I did. Realize too that I am 30 years old, 6'2" tall, 195 pounds, and usually run and work out in the gym, so my physical conditioning (at least at that time   ) was pretty good.

Another WB's pilot I talked too once, took the same flight I did, and from his discription, had many more problems with the G effects. So realize that G effects are different for each individual person, and that AH is looking at the "average" person.

Personally, I like the way that AH is handling G effect, I think it is quite realistic.



------------------
Vermillion
WB's: (verm--), *MOL*, Men of Leisure, Goldlandia
AW's: (verm) ACCS, Aerial Crowd Control Services, Cland

[miko2d]

 In a T-6 trainer while relaxed, I blacked out completely under 4Gs. They actually will not let you exceed 4 Gs, let alone pull 5 or 6. The plane I flew in was 54 years old.

 I am sure with anti-G strain maneuvers I would have been able to withstand that much without blacking out. But when relaxed or preoccupied with someting else (looking around), the tunnel effect started around 3Gs.

 It may be possible to pull Gs and avoid blackout while looking froward and paying attention. There is no way to avoid blackout while trying to pull Gs and look around at the same time. I conclude that it was a safe bet that any during WWII if you saw a plane not flying  in a straight line, you could be sure he is not checking his 6 or 3 or 9 or even up. Maybe only 45% from the forward view.

miko--

[This message has been edited by miko2d (edited 10-04-1999).]

[Rawhide57]

After my first couple of flights in Aces High, I was very disappointed with the stall/blackout/redout characteristics of the flight model.  Over a 1/2 inch back on the joystick at any speed, and I was hit with the stall flutter and/or a blackened screen.  IMO, this greatly reduced the enjoyment I received from this simulation.

One thing I did notice, however, is that this occurred when using my MS Precision Pro stick, a stick which is known for its quick movement.  I found that when I used another joystick, like the Saitek X-35/36 combo, I experienced fewer stick induced blackouts/stalls.

Slow or gradual control inputs have helped me tremendously in avoiding GLOC/stall scenarios, making for a much more playable game.  While I still think the AH flight model could use some tweaking, some of you who are experiencing this may try to dampen your stick controls to overcome the tendancy to "rack the stick back" during manuevers.

I know this debate will rage on the "realism" of GLOC in WWII fighters, and the way it is recreated in this and other flight sims.  Personally, having experienced acrobatic manuevers in several hi performance prop driven aircraft, I do think the AH flight model is a bit too touchy right now for my taste.  

Now, if they could just simulate some vomit floating around in the cockpit...now there would be some realism...at least in my case...LOL

[CptTrips]

>I do think the AH flight model is a bit too
>touchy right now for my taste.

Part of that may be because you can't feel the g forced building up physically and often your first clue is that tunnel closing in.

Maybe they should take the acceleramotor off the dashboard and have a g-readout text at the screen top that can be watched from all view.  Or have the pilot start grunting as he approaches gloc loads. ;>

Regards,
Wab

[Rawhide57]

"To try and produce a faithful representation of WWII era combat and leave out GLOC would be like modeling WWI Camels and DR. 1 without including the strong engine torque that was their hallmark characteristic. ;>"

Hmmm...seems like placing "g-meter text readout at the top of the screen" would be stretching the "faithful representation of WWII era combat" a little far, don't you think?  What's next? HUD?   LOLOLOLOL

[CptTrips]

>Hmmm...seems like placing "g-meter text
>readout at the top of the screen" would be
>stretching the "faithful representation of
>WWII era combat" a little far, don't you
>think?

Maybe.  Is that worse than the acceleramotor gauge on the dash?  I dunno.  Did all the aircraft modeled in AH have those in real life?  If the gloc was a little more gradual it might not be needed at all.

Regards,
Wab

[Bohica]

Heh heh Vermillion catching someone looking down is an OLD trick that unkind/vicious/stupid pilots like to do to newbies. (The other trick is to turn up the heat to em airsick)  You wake up wondering what is happening and why you are flapping your arms <G>.  In this case I will assume that it was unintentional, and not that he was mean.  The rest of the flight seams to bear out that observation.

Just remember that fighter pilots that are driving the plane know when the load is coming so they can prepare themselves.

The rapid inflation Gsuits were developed in response to the very sudden onset of G's that the F-16 is capable of.  It was revolutionary in its ability.

The question of the rollercoaster (I forget who responded and am way too tired to look back, my apologies) I may be in error.  I got my information from an old show on the discovery channel when Lightening Loops first came out at Great Adventure in NJ.  They did a show on it.  They said that the forces in the front seat were highest going into the loop, and back seat was highest on the downside coming out of the loop and that  it momentarily touched 6 under those circumstances.  

Lightning Loops was the first roller coaster to loop to the best of my knowledge, and the cars were catapulted towards to loop, for those who never road it.  (I can remeber going to 6 flags Great Adventure 20+ years ago to ride that one roller coaster, it was awesome but over quick! It was only A loop, foward then back, catpulted in both directions.  Whole thing over in something like 40 Sec, except for the 2 hour line to get on it)



------------------
Bohica
900th Jaguars

[ft]

It seems to me that right now the blackouts are a plain function of the number of G's you are pulling at any instant, ie:

BO=f(g)

A more realistic representation IMO would be to allow a blackout to build up over time, something like:

BO=time integral of (f1(g) - c) + f2(g), with c being a constant and c>f1(g=1).

f1(g) would increase fairly shallowly with increasing g. You could pull g's all day as long as f1(g)<c. When you go over that threshold, you'll start building up to GLOC. When you go down below that threshold, the effect would start fading.

The f2(g) part would increase more rapidly at higher G's, making sure that you get instantaneous BO if you pull those really heavy G's. You'd notice G spikes more if you'd been pulling G's for extended periods of time before.

This would fit better with what I've read about the effects of G's on the human body. More factors would be needed of course, and quite a bit of tuning for sure.

Just my 16 swedish ören ($.02  

I'm sure HiTech and crew have looked into this, and are still looking into it. The GLOC we have now is most likely a beta thing if you ask me.

[This message has been edited by ft (edited 10-04-1999).]