Anti-G suits. At high-G turns, the blood tends to rush to the lower extremities. It's the lack of blood and oxygen to the brain that causes the pilot to black out. At high-G forces, the bladders in the anti-G suit inflate and compress the limbs, preventing the blood from rushing into them so that there will be sufficient blood and oxygen supplied to the pilot's brain.

Hello Guest,

Your standard healthy, fit (inexperienced) pilot can endure maybe 2-4 G of acceleration in a quick turn before his vision and mental faculty are affected (a bit more acceleration for a female.) First remarkable symptom is loss of color vision and peripheral vision and it will progress up to complete black-out (unconsciousness.) This occurs as the person's blood flows from the head (and brain) into the torso and lower extremities, depriving the brain of oxygen.

The pilot can gain a couple more G's of endurance by strengthening the muscles of the abdomen, chest, back and legs. Then, when experiencing higher Gs, contract those muscles as much as possible (which can itself interfere with piloting) constricting blood vessels and providing less volume for blood to flow into and through, therefor leaving more blood in the brain.

A variety of other conditions can influence or assist the pilot. One is the pilot's level of stress and restfulness. (It is best the pilot is up on sleep.) Increased oxygenation of the blood (by breathing oxygen) is helpful. Configuration of the pilots seat (the pilot's position and level of support) is significantly influential. Genetic factors are also influential (some pilots simply endure more acceleration than others.) It is worthwhile, also, to be aware that onset of symptoms requires some amount of time. If high-G transients are sufficiently short they will not incapacitate. (Enduring high-G conditions, such as some types of spin, can last long enough to overcome all preparations.)

There are external means of assistance, as well. Anything that prevents blood flow out of the brain is helpful. One such system involves inflatable bladders positioned over thighs, back and abdomen which are engaged pneumatically when the aircraft enters a maneuver. These are sometimes called "G-suits."

Aerospace medicine references will say that with all these things optimized the pilot can handle up to 7.5 G of acceleration. In many cases experienced combat pilots can improve on this, occasionally to the point of being still conscious as the airframe is overstressed.

Perhaps these will be more helpful: Some views by others, on g-induced Loss Of Consciousness, on g-Suits, and on Space and Aerospace Medicine.

finally, a very thorough Powerpoint presentation from the US Navy's Medical Training Command's Naval Operational Medicine Institute on G-Tolerance Improvement Program (which I think is public domain.)

...unable to answer...ENVY...overpowering me!

Thank you.

This is no bulls#*t!!! If you're a Russian fighter pilot, you drink lots of vodka, smoke, and eat anything fatty and salty that will give you high blood pressure. Although they use G-Suits, they believe that the high blood pressure give them an extra edge against blackout. Perhaps they're right!

Hey Vermin!

That's great!!! I want to become a Russian fighter pilot. Where do I apply?

PD: I think they will need many new fighter pilot just like me after their last military parade (few days ago) At the red square, I fit perfectly. Last time I flew a military airplane was 22 years ago, same age of those airplanes they flew at the parade. Furthermore, It's only going to be a cold war again, so what can I loose?

(I'll certainly loose the Vodka if I don't.)

Wangito.

How's that volcano treating you? I know your country is like a bazillion mile long and about twenty feet wide, so you may not be anywhere near it. However, it sure looks nasty!!!

You damn right.

It surely is nasty... predominant winds are south-west so ash is being blown to Buenos Aires (No more... as buenos aires means good air in Spanish.) Argentina. so being about 1000Km north, we hardly notice it.

However my country is very very small, and the smoke there is coming from totally different source...But both sources, volcanoes and bombs, seem to be uncontrollable and have no immediate solution...

Wangito.

You guessed it. I am from Israel.

When Heikki Kovalainen crashed into the tyre wall at 140mph in the Spanish F1 race the deceleration was recorded at 24g yet he was uninjured & will be racing again this weekend in Turkey. A testament to both the fitness of the driver & the design of the car.

Remove the pilot from the aircraft and 2 things happen:

1. They don't die or get captured; since you don't lose pilots, you can keep the best one's for combat.......read about the effect that the battle of Midway had on Japanese pilot skill level present at the Marianas Turkey Shoot.

2. You can design the aircraft to perform at G forces that would kill a human, if the human were on board;

Oh Yeah, you can eliminate all of the biomass support systems(windscreen, oxygen systems, visual displays, etc) which will reduce the cost and weight of the aircraft.

Above replies address black outs but not red outs.

Black outs are caused by positive G's that force blood from the brain, and red outs are caused by negative G's that force excess blood into the brain.

Above is an image of a P52, a dual fuselage aircraft with a pilot in each fuselage. During a rapid snap roll, one pilot would black out and the other would red out.

In effort to minimized these effects, fighter aircraft designers place the pilots as close as possible at then the center of rotation and pitch.

Snap-roll or any other roll.

Both cockpits will turn the same direction, hence same sign "g" loads. Only that one pilot will have different "g" factor being in different arc position. In order to get different sign (negative or positive,), one cockpit must make an inside turn (positive) while the other must make an outside turn, (negative) or one pilot flies up-right and at the same time the other flies inverted. that, fortunately, for the pilots (and the airplane) doesn't happened.

Just so that you understand the procedure For Snap-roll:

1. Fly strait and level, At the maneuver speed (different for each airplane).
2. Pull hard on the stick all the back.
3. When the nose is 30° to 40° over the horizon,
4. Push hard left or right rudder all the way in, keeping the stick all the way back,
5. Once back in up-right position, release pressure on the stick and the rudder,
6. Resume strait and level flight.

Where did they split directions?

Wangito.

If you're going to turn, I want you to take it outside, young man!!!

wangito,

Unless I have forgotten how to fly. Your procedure is for a barrel roll which does not require ailerons. When ailerons are applied, one wing moves up and one wing moves down. In the P-82, the cockpits for the pilots are not on axis with the centerline of a roll, they are in the wings. Therefore, one pilot moves up and one pilot moves down.

Hey Snave!

You wrote:Unless I have forgotten how to fly

Maybe you have, but Assuming that you haven't, there are two possibilities, Either you have never done neither barrel roll or a snap-roll (which is probably the case),or that we are talking about two different maneuvers...(Which probably is not the case...)

Quote: "The barrel roll is a maneuver in which the aircraft rotates 360° around the longitudinal axis while the nose of the aircraft describes a circle around a reference point real or imaginary. The circle described should be of constant radius around the reference point." unquote (Van sickle's Aerobatic flight maneuvers, p.439). The same description of a barrel rolls appears in various other flight maneuver guides both military and civil. Hence the name, the aircraft flight path describes a flight around an imaginary barrel.

If you can fly a barrel roll as described here without the use of ailerons than you must know something about flying that no one else but you knows. Actually in a not high performance airplane, such as the Stearman, Great Lakes or a Decathlon, if you do not apply full aileron you will never finish the roll and will soon find yourself in a steep dive nose down...

This is nothing personal you are simply wrong.

Wangito

CPL,CFI, SE and ME CFIH CFII. since 1968

But why two pilots?! And what determines who gets to steer?

Why wasn't it built like a P-38 with one pilot?

I have to speculate as you probably understand I wasn't part of the design team...

I do believe though that this was an operational issue. the same that later was behind the two pilot crew on almost all large "F","B"and "P" aircraft.

1. four eyes are better than two. These are the days of the pre fully computerized WDS (weapon delivery system) So while one flies the other is responsible for WDS.
2. number two has enough flying skills to bring the bird back home in case of #1 becoming impaired. pilot redundancy.
3. lower pilot work load. Fatigue and overload are the Fighter pilot worst enemies. I believe this was the main reasoning behind this especially on long range missions.
4. During the Vietnam war Back sit F4's pilots were also called "navigator" same for later F15's, but they were tandems. not side by side.
5. Who gets to steer? The designated PIC (pilot in command).The navigator or weapon officer will usually be a lower ranking officer, or if same rank than usually with less seniority. and will fly the airplane whenever told to do so.

That reminds me of the standard practice at the officer's mess. "Always squeeze the lemon in the direction of the lower ranking officer, Always!"

Wangito.

You should see the collection of WWII vintage birds flying into Moffet Field today...

B-17s, B-29s, P-51s, and a whole bunch of others I can only guess at. There's one B-17 that you can ride for donating to charity. Once air-born, you're welcome to unstrap and roam around!

Why two pilots?

The P82 was developed during WWII. There was no time to design an aircraft from scratch. The P51 was very successful. Taking two production P51 Mustangs and sticking them together got the required increase in range that was needed and was quick to get it into production as it only required designing a wing section to join the two fuselages and a section of tail. They could be built on the same production line as the P51 and new production tooling was minimal. These birds saw no action in WWII as the war ended. They did see a little action during Korea. The problem that the pilots could red-out/black-out while flying evasive maneuvers and the fact that jets were starting to become viable, made the plane obsolete.