Aerobatics & G-Tolerance

Your body's ability to combat G's, both positive and negative, depends not only on keeping in good shape but also knowing how to combat G's. As you all know, you are sitting at one +G browsing this website. If you weigh 150 pounds now, then under five or six +G's, you will weigh 750 or 900 pounds! That is a lot of force trying to flush all the blood from your head down to your toes. You can be in the best shape of all, but if you don't strain against the +G's, you will lose too much blood and could pass out...that's very bad.

In my time flying F-16's, we experience high levels of +G forces, up to nine sustained! There are a few key techniques I use to make sure I don't pass out. 

1. Keep in shape by lifting weights and running a couple times a week for a short amount of time.

2. Take a deep breath just prior to pulling any +G's.`(more than three to four)

3. Strain against the +G's by tightening the muscles in my legs, stomach and chest.

4. Take a breath every three seconds. (only if you are pulling +G's longer than that)

The Air Force put me through centrifuge training before I started flying the F-16. Here is a video of me sustaining 9 G's for 15 seconds. Here, you can see the breathing and straining techniques I am talking about. 9 G VIDEO

I realize that flying aerobatics in most planes today will not put you in the high +G environment of the F-16. Therefore, you may not need to strain very hard, depending on your individual tolerance level. When I started flying the Pitts, I thought I wouldn't need to strain very hard or at all since my +G tolerance is pretty high. However, what I have found flying the Pitts is that if I take a deep breath and strain, along with breathing every three seconds, my overall energy level is higher throughout my flight. I don't get as tired as I did before. My guess is that you, like me, want to be as alert as possible all the way until I land and shutdown. This is why I recommend that you treat any +G's, whether it's three or four or more, with a serious approach of wanting to stay on top of them. If you ever feel like you are behind the power curve and getting light headed or tunnel vision from too many +G's, abort the maneuver if you can. Anlayze why you feel the way you do, is it that you didn't strain at all? Maybe it's just not your day for pulling +G's? That happens to everybody once in a while. The key to staying alive is to throttle back, even go home land, and try another day. 

The other side of the coin are negative G's. I do not have a lot of experience pulling -G's, so I won't give any advice on how to combat them, except for one very important thing. Do not use the technique I gave you on +G's to combat -G's. This technique is designed to push the blood up to your head and when you pull -G's, that is exactly what you don't want. Please find a qualified aerobatic instructor and ask him/her about how they deal with the negatives.

I hope this helps a little bit, remember, don't do anything in your plane you haven't done with a qualified flight instructor first. This means pulling G's as well. It's always better to find new things out when there is someone else there to make sure everything goes well. Good luck!

Living the Dream,
Ed Hamill