In article ,
Cub Driver wrote:

On Thu, 30 Jun 2005 11:52:33 -0400, "Happy Dog"
wrote:

It really depends on the individual. Almost anyone can tolerate 2Gs for a
sustained period but moving about or lifting anything heavy would be
difficult. I think that the cutoff point for the average person (sustained)
is around 3.5Gs.

A young pilot in good physical condition ought to tolerate 5 Gs. With
specialized training, as was given to Spitfire pilots in WWII, 9 Gs is
possible.



Most healthy military pilot sorts (completely healthy and fit) have a
RESTING G tolerance of 4-5G, that is without any muscular contraction or
strain maneuver.

Leg and abdominal muscle straining typically adds another 0.5-1.0G on
top of this resting tolerance, and then adding the G-Strain maneuver
(pushing against a closed glottis to increased intrathoracic pressure)
adds above that.

I recently spun in the centrifuge at Brooks AFB and started to gray out
at around 4.2-4.5, and then had to begin the strain (lightly at first of
course) at around 5.3-5.4 G. I was able to go to just over 9G without
blacking out or G-LOCing which was fun (in hindsight) but it REALLY is a
lot of work.

Tolerance varies widely, with some graying out at 3.5 and some going to
7+G with no strain whatsoever.

Good lower limb and abdominal muscle strength helps peak tolerance, and
good cardiovascular fitness seems to help with repetitive Gs.

-Chris Schmelzer, MD, Captain
Medical Corp, Flight Surgeon
110th Fighter Wing, Michigan ANG

--
Chris Schmelzer, MD
Capt, 110th Fighter Michigan ANG
University of Michigan Hospitals
Ann Arbor, MI