YF-21 unrestricted acceleration

[Ayle]

Hi, I've just finished watching the Macross Plus movie, and was wondering what kind of acceleration the YF-21 was able to achieve to cause Guld eyes to basically pop(that was quite disgusting by the way)... MAHQ mention G-limits for the airframe of +32.5 G/-17.2 G. And human have been shown to survive accelerations in the hundreds of Gs with only bleeding as the result... So were the eyes crushing and bowels flattening really an example of what happens when submitted to heavy acceleration or was that just thrown in there for the wow factor?

[Areku]

Humans have survived hundreds of g's of acceleration, but only for tiny fractions of a second, such as in a collision. For more than a sliver of a second, the human tolerance falls off dramatically. Even with training and expensive suits meant to counteract high g's, most fighter pilots can only handle 9 g maneuvers. The brain is most susceptible to high g, due to physical location and blood flow, and the eyes are right behind it in vulnerability.

[Brave Fencer Kirby]

Depending on the force, direction, and length of the gs being put on a person, effects can differ dramatically. As Areku said, the general rule of thumb is that a properly trained and equipped fighter pilot is expected to remain in control of his aircraft while doing 9 gs for a handful of seconds at a time.

Depending on how many gs he was actually experiencing and how long they were going on, squishing his eyes isn't outside the realm of possibility. Your eyes are basically round sacks of goo -- they've got no support structure and they aren't made of particularly tough material. Most effects of high acceleration that we're familiar with from real-world experience have to do with blood flow. When blood is pulled away from the eyes and they start to lose oxygen, vision starts to fade out (first peripheral vision, then color vision, then complete blindness), and when blood is pulled away from the brain it effects judgment and eventually results in unconsciousness. On the flip side, negative gs pushing blood up INTO the head can cause "red out" (as opposed to grey out and black out from positive gs) where the additional blood in the eyes causes a red tint to vision. It can also cause nastier things like permanent retinal damage or strokes from too much blood pressure in the brain.

Anyway, short version is that yes, it's possible for extended high gs to cause fragile body structures like eyes and intestines to collapse, but the chances of being conscious during it are very low.

[TakaTahuNuva]

Considering that Guld is half Zentreadi, we can assume he can withstand high gs longer than normal humans (though I don't think exact numbers are known).

[Ayle]

I'm aware off the effects of pulling to much Gs, I might be nitpicking but he was basically flying in straight line when his eyes went "pop", basically he was experiencing an acceleration vector in the direction in which the body is the most resistant to it... I guess I'm just really nitpicking

[AnimeMun]

I'm aware off the effects of pulling to much Gs, I might be nitpicking but he was basically flying in straight line when his eyes went "pop", basically he was experiencing an acceleration vector in the direction in which the body is the most resistant to it... I guess I'm just really nitpicking

That isn't the only factor that you should be taking into account. Beyond that you should note that the YF-21 was nowhere near perfect condition when he removed the limiters. It was quite badly damaged actually. I'm sure that has a huge effect on the G resistance provided to the pilot. Although at that point he didn't really need his eyes more anyway. Guld knew he was going to die and being a mind-controlled unit, he didn't need his eyes to fly it. The cameras were all he needed to do what he needed which was to defeat the X-9.

Other than that we can examine the WAY they popped, which denoted that the Gs were pressing straight back. At that point its like setting them into a 30 pound steel power grip vice, they crush like paintballs would. Guld was lucky to be able to last a full minute at that speed.

[Brave Fencer Kirby]

It was quite badly damaged actually. I'm sure that has a huge effect on the G resistance provided to the pilot.

There's really nothing in the way of ship design that can reduce g-stresses on the pilot. Either it's pulling the gs or it isn't. Barring some magitech like an "inertial compensator" or the like, the very best you can do is give the pilot equipment like g-suits to help them function better in higher gs.

[blind_dead_mcjones]

There's really nothing in the way of ship design that can reduce g-stresses on the pilot. Either it's pulling the gs or it isn't. Barring some magitech like an "inertial compensator" or the like, the very best you can do is give the pilot equipment like g-suits to help them function better in higher gs.

thats not 100% true, there is one way of reducing the stress of G's on the human body through aircraft design, but it requires the pilot to be lying on his stomach instead of sitting, which unfortunately is not a good position to be in when ejecting.

[Ayle]

I'm aware off the effects of pulling to much Gs, I might be nitpicking but he was basically flying in straight line when his eyes went "pop", basically he was experiencing an acceleration vector in the direction in which the body is the most resistant to it... I guess I'm just really nitpicking

That isn't the only factor that you should be taking into account. Beyond that you should note that the YF-21 was nowhere near perfect condition when he removed the limiters. It was quite badly damaged actually. I'm sure that has a huge effect on the G resistance provided to the pilot. Although at that point he didn't really need his eyes more anyway. Guld knew he was going to die and being a mind-controlled unit, he didn't need his eyes to fly it. The cameras were all he needed to do what he needed which was to defeat the X-9.

Other than that we can examine the WAY they popped, which denoted that the Gs were pressing straight back. At that point its like setting them into a 30 pound steel power grip vice, they crush like paintballs would. Guld was lucky to be able to last a full minute at that speed.

There is only one problem with that: Eyes only weight about 10 grams, which i s clearly not enough for them to get crushed under their own weight. I do agree with the rest of what you said though, I think the production team might have been looking for a way to say the he had completely become one with the machine or something like that. On another note, is there any kind of epilogue or universe story saying if they recovered the wrekrage at the end?

[AnimeMun]

There is only one problem with that: Eyes only weight about 10 grams, which i s clearly not enough for them to get crushed under their own weight.

Well if your eyes are being pushed backwards thats not them being crushed under their own weight. Its being pushed towards his brain by the increasing air pressure inside the cockpit. Due to the increasing speed and G forces. After watching the scene in question once more I noticed that the speed being taken was also going between different levels of the atmosphere on top of going so fast that it was burning the paint off the unit.

Sure he is in a specialty pilot suit meant to compensate for increasing air pressure since these units were made for entering and exiting the atmosphere. However with the limiters released and the fighter being taken to its highest absolute speed I'm certain it isn't working that well at that point.

Even his own arms are being pushed back enough to crush his intestines, not to mention that his ribs are probably all but shattered at this point.

[MrMarch]

There's little solid statistical information on the speeds and inertia from that battle in Macross Plus. However, we can derive some information from official sources. The QF-4000 (AIF-7S) Ghost Fighter from Macross Frontier is based upon the X-9 Ghost and the Macross Chronicle supplied statistics for the Frontier Ghost, listing a maximum airframe design load of 24.5g. While this airframe rating is not the official equivalent to the load that can be sustained by the original X-9 Ghost, the QF-4000 (AIF-7S) load rating is a good approximate indicator of the original X-9 capabilities.

We also know from the Macross Plus animation that the YF-21 and the X-9 began melting and fracturing under the same acceleration stress at roughly the same time. So it's likely relative loads for the two craft are similar (with the YF-21 perhaps being a bit superior), which would place the X-9 capabilities somewhere beneath the +32.5g rating of the YF-21. Hence the final acceleration for the two craft in battle was likely somewhere in the range of high 30s to 40s of gees. Even if the two craft had identical acceleration limits, the X-9 would have an impossible advantage over the YF-21 because a machine needn't be limited to mostly 9-12g maneuvers like human-piloted craft. The X-9 could probably achieve 20 g maneuvers routinely without issue. But once Guld was willing to sacrifice his life and his aircraft, the advantage enjoyed by the X-9 would temporarily disappear. Guld then used his aircraft as a self-propelled warhead and smashed the X-9 to pieces.

Hope that helps.

[Ayle]

There is only one problem with that: Eyes only weight about 10 grams, which i s clearly not enough for them to get crushed under their own weight.

Well if your eyes are being pushed backwards thats not them being crushed under their own weight. Its being pushed towards his brain by the increasing air pressure inside the cockpit. Due to the increasing speed and G forces. After watching the scene in question once more I noticed that the speed being taken was also going between different levels of the atmosphere on top of going so fast that it was burning the paint off the unit.

Sure he is in a specialty pilot suit meant to compensate for increasing air pressure since these units were made for entering and exiting the atmosphere. However with the limiters released and the fighter being taken to its highest absolute speed I'm certain it isn't working that well at that point.

Even his own arms are being pushed back enough to crush his intestines, not to mention that his ribs are probably all but shattered at this point.

I used the term weight loosely. w=mg and in guld case it was F=ma, meaning that the force on his eyes is proportional to their mass, and eyes are too light to get crushed by simple acceleration unless you are talking about 500-1000Gs which is out of reach for the X-9 and the YF-21. Air inside the cockpit is moving as the same rate the rest of the fighter is so it doesn't really affect the pilot inside.

[latenlazy]

I used the term weight loosely. w=mg and in guld case it was F=ma, meaning that the force on his eyes is proportional to their mass, and eyes are too light to get crushed by simple acceleration unless you are talking about 500-1000Gs which is out of reach for the X-9 and the YF-21. Air inside the cockpit is moving as the same rate the rest of the fighter is so it doesn't really affect the pilot inside.

...I don't think the eyes were crushed under their own weight. I think they were crushed against the bone surrounding the eye socket....

[Brave Fencer Kirby]

What he's trying to say is that your eyes don't weigh enough for gs to make them squish. The force put on an object due to acceleration has to do with its mass. F(orce) = m(ass) * a(cceleration), after all. With the eyes being relatively low mass, the force put on them by the acceleration of the ship is relatively low as well.

Whether the force is enough to actually squish your eyeballs after an extended period of acceleration, I have no idea.

[His Divine Shadow]

The human body is better at surviving g-forces that are perpendicular to the spine. In general when the acceleration is forwards, so that the g-force pushes the body backwards (colloquially known as "eyeballs in") a much higher tolerance is shown than when the acceleration is backwards, and the g-force is pushing the body forwards ("eyeballs out") since blood vessels in the retina appear more sensitive in the latter direction.

Early experiments showed that untrained humans were able to tolerate 17 g eyeballs-in (compared to 12 g eyeballs-out) for several minutes without loss of consciousness or apparent long-term harm.

- Answers.com under Physics and Kinematics

[SchizophrenicMC]

You're only taking acceleration into play, here. Sure, eyeballs aren't massive enough to be crushed under their own weight during that kind of G-loading. However, add to that, the factors of increased temperature and air pressure, due to increased friction from the added speed (burned the paint right off), and the pressure Guld must have been putting on his eyes, squeezing them shut, and the total stress on them could very well have crushed them. Eyeballs, even Zentraedi, are weak little buggers.

As for the bowels being crushed, I'd say his heavy arms, plus space suit, having their weight multiplied by about 30 as he pulled into those fatal maneuvers, would probably be able to do the same.

Also, considering it's only in the Movie Edition that his eyes get crushed (In the OVA, we don't see this viscera), it's just for wow factor. Even what I'm saying is a MASSIVE stretch.