Author Topic: G-forces?  (Read 372 times)

Offline Charge

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G-forces?
« on: April 08, 2004, 01:52:22 AM »
Hitech said this in another thread: "All planes black out at the exact same G load."

IMO there are cockpit drawings around which show a rather different configurations in aircraft which, again, makes you suggest the pilot's G tolerance differed between aircraft.

The best configuration I have seen has been in  109s as the pilot sits at almost the same level his feet are. I'd think this should give a rather marked advantage in high speed high G maneuvers against opponents whose a/c have a more upright sitting position.

The problem is, that there is no written documentation about the subject AFAIK, but the common sense says there is a difference depending on the sitting position. How marked it is? ->I don't know.

Does anybody have any data on this subject?

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Offline Kweassa

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G-forces?
« Reply #1 on: April 08, 2004, 02:01:50 AM »
Does black out come and go as abruptly in AH?

 I've noticed some differences in the 'timing', 'interval', and situation where a pilot enters grey out/black out in AH and FB.. and I'm kinda curious.

Offline Wilbus

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G-forces?
« Reply #2 on: April 08, 2004, 08:16:50 AM »
Charge, both the 190 and 109 has the pilots feet very high up to reduce G effetcs on the pilot, and yes it worked and still works.

Read the RAF report of the 190 and I belive it is one of the things they comment on.

The same thing us used in modern planes, specially aerobatics planes I believe. The more you are able to "lie" down the less blood will be pushed down your feet.
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Offline GRUNHERZ

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G-forces?
« Reply #3 on: April 08, 2004, 08:19:44 AM »
Plus the 109 and 190 had a more reclined seat than the allied planes. But some allies got g-suits late in the war. I think some LW had them too...

Offline myelo

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G-forces?
« Reply #4 on: April 08, 2004, 03:07:08 PM »
If you know the angle of the seat, it’s pretty straightforward to estimate the effect on G tolerance. That’s because reclining the seat works by decreasing the vertical height from the heart to the eye. In other words, the improvement in G tolerance for loss of vision is approximately liner with the reduction in the vertical height from the heart to the eye. For example, a 75-degree seat back angle reduces this height to 50% and would approximately double G tolerance.

Burns, J.W., Re-evaluation of a tilt back seat as a means of increasing acceleration tolerance. Aviation, Space, and Environmental Medicine, 1975, 46, pp.55-63.
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Offline Orig

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G-forces?
« Reply #5 on: April 08, 2004, 04:33:29 PM »
If you really want to understand G forces, contact the centrifuge people down at Brooks AFB in San Antonio and see if they have room for you in an orientation course.  I've seen tv shows where media people (usually science shows) get some training and a centrifuge ride, so it's not impossible to get in.

It's not exactly pleasant, but it's about the only way to really learn about the physiology and effects of G forces.