F-16 pilot G tolerance

[Fri13]

I've read Formula One drivers get almost 5g's when braking. I wonder what they get in the high speed turns? They need to do it for 2 hours too.

 

But they do quickly recover as it is short period and the blood doesn't get drawn from their brains like pilots does for many seconds.

But sure, 50 laps with few high G turns and few high G deceleration/acceleration parts and it is serious workout.

Edited May 18, 2019 by Fri13

[BuzzU]

That's true but for a steady 2 hours, it must be taxing. I know they all train hard to be able to do it.

[=Panther=]

Cart had to cancel an event at Texas Motor Speedway a several years ago due to high Gs on the drivers. I suspect that was just like a centrifuge due to the constant left turning, even with the little bit of straight away it had, the cars were moving pretty quick.

[L-39beeratros]

I've read Formula One drivers get almost 5g's when braking. I wonder what they get in the high speed turns? They need to do it for 2 hours too.

 

 

Formula drivers get Gs in different axes than pilots, in axes where Gs have less effect (left-right and forward-back, not up-down like in an aeroplane)

[BuzzU]

Formula drivers get Gs in different axes than pilots, in axes where Gs have less effect (left-right and forward-back, not up-down like in an aeroplane)

 

 

True, but the left-right should be similar.

[mkiii]

Not really, there will be much less work involved for the heart to pump blood over the lateral few inches in an x/y axis compared to the 4 feet or so that it has to travel from the bottom of the legs to the brain, and as mentioned above - this is not many seconds at a time - but just a few.

[BlackLion213]

I heard that the seat is in reality inclined because they couldn't fit it in in 'normal' angle and they made up the whole 'G tolerance' story later. Could be wrong, who knows :)

 

Yes, I have heard the same and the G tolerance improvements from inclining the seat proved to be statistically insignificant and added some other ergonomic drawbacks. Hence the later F-22 would have the more standard incline of 14 degrees (I think?).

 

The increased seat recline makes more sense if you treat the vascular system as a vertical fluid column, but physiologically it doesn't quite work that way. Especially since the primary area of interest are the relative position of the common carotid (and brachiocephalic) branches from the aortic arch. With pilots leaning forward to move their head, the functional angle is essentially unchanged from the usual inclination of 14-18 degrees.

 

While elevating the legs can help a little, the effects of the G-suit is really far more powerful than the leg position. Young healthy people won't get as much pooling in their legs since they have healthy valves in their veins and the G-suit completely (or nearly so) collapses the venous system during inflation. Plus, the path of least resistance for blood is into the huge and valveless system called Batson's plexus. which invests the entire spine (including the epidural venous system) and lower GI tract. Batson's has a huge capacity and cannot be effected by external factors like the G-suit. It is also the reason that fighter pilots tend to get a lot of hemorrhoids.....

 

In many ways, the G-suits effects on the legs serves to improve cardiac preload by driving venous blood out of the legs and helping to offset the blood directed into Batson's plexus.

 

So overall, the G-tolerance issue is not really a factor compared to other combat aircraft.

 

-Nick

[VZ_342]

Yes, I have heard the same and the G tolerance improvements from inclining the seat proved to be statistically insignificant and added some other ergonomic drawbacks. Hence the later F-22 would have the more standard incline of 14 degrees (I think?).

 

The increased seat recline makes more sense if you treat the vascular system as a vertical fluid column, but physiologically it doesn't quite work that way. Especially since the primary area of interest are the relative position of the common carotid (and brachiocephalic) branches from the aortic arch. With pilots leaning forward to move their head, the functional angle is essentially unchanged from the usual inclination of 14-18 degrees.

 

While elevating the legs can help a little, the effects of the G-suit is really far more powerful than the leg position. Young healthy people won't get as much pooling in their legs since they have healthy valves in their veins and the G-suit completely (or nearly so) collapses the venous system during inflation. Plus, the path of least resistance for blood is into the huge and valveless system called Batson's plexus. which invests the entire spine (including the epidural venous system) and lower GI tract. Batson's has a huge capacity and cannot be effected by external factors like the G-suit. It is also the reason that fighter pilots tend to get a lot of hemorrhoids.....

 

In many ways, the G-suits effects on the legs serves to improve cardiac preload by driving venous blood out of the legs and helping to offset the blood directed into Batson's plexus.

 

So overall, the G-tolerance issue is not really a factor compared to other combat aircraft.

 

-Nick

 

Oh sure, now you’re talking all medical type stuff. Whatever happened to the güd olde days, when hyperbole and emotion was all that was needed?!

 

:P

[Basher54321]

Have only seen mentioned by Chuck Yeager (was not a fan) and Melampy mentions it - however actual research on the LWF design concept suggests the USAF centrifuge experiments showed it increased G tolerance ~1.5G and tracking levels 33 to 55% - so looks like it was a consideration before hand and valid for a tech demonstrator.

[_mu110_]

If anyone is interested, there's also an early fighter pilot podcast episode that talks about a lot of these topics: http://www.fighterpilotpodcast.com/episodes/006-pulling-gs/

[Django]

Perhaps with this project ED will review how G tolerance is modelled in the sim with a view to simulating

type systems???

[blkspade]

There is no reason to change anything G tolerance related. None.

Since the seat is one of a metric shitton of factors and most of them are based on the actual pilot this whole thread is laughable at best.

 

Next step would be more in shape DLC pilots with a higher g tolerance, :lol:

 

I think the point you are missing is that in DCS everyone is the same pilot in every jet, so the only variables are literally what the plane offers.

[Fab]

I have pulled 1 G in an F-16, and it was fine. I don't see what all the fuss is about - it was no worse than pulling 1g in a Mirage or F4. Reclining seat was more comfy though.

 

Erm.... 1 G is the force you experience just standing on the ground:music_whistling:

[backspace340]

Erm.... 1 G is the force you experience just standing on the ground:music_whistling:

 

[dali]

GLOC depends on many things, mainly on how well person is resistant (pilot's height is one of the main factors), pilots physical state, the protection (g-suite), techniques with which one fights g force (breathing, contracting the abdomen etc), and of course the inclination of the seat. When I was tested before I was enroled in the air force, I could withstand 5.5 g before GLOC, without training, g suite and special training. Later when flying, 7.5 G, just using g suite.

[tusler]

I wonder out of Batman, Superman and the Hulk and Thor who can take the most G

[Svend_Dellepude]

Hulk would be my guess. Very muscular and wide dude. Although, superman and batman seems to be wearing some kind of G-suit already. Batman seems to have the newer version though.

[Hummingbird]

If the reclined seat provides an advantage in G tolerance then ofcourse it needs to be modelled, even if it is small (0.5 - 1.5 G's), as it's part of the design of the aircraft.

[dali]

women and short people are best equiped for fight against gloc, since the distance between the brain and the heart is shorter than with tall, bulky guys. inclination of the seat is doing just that - further reducing the distance between brain and heart.

[BuzzU]

inclination of the seat is doing just that - further reducing the distance between brain and heart.

 

That doesn't seem right. You can't change that distance.

[26-J39]

in DCS everyone is the same pilot in every jet, so the only variables are literally what the plane offers.

 

 

Finally! thank you, my shout if we ever meet up ;) Close thread :lol:

[_mu110_]

That doesn't seem right. You can't change that distance.

 

I think he meant vertical distance.

[The Falcon]

it's a small amount of tolerance g, but in dogfight it's important

[antagonist]

That doesn't seem right. You can't change that distance.

 

It's not about physical distance between them, it's about the hydrostatic head the heart has to pump blood up against.

[dali]

It's not about physical distance between them, it's about the hydrostatic head the heart has to pump blood up against.

 

that is what I ment, thx