Previous in Forum: How Much Green and at What Cost?   Next in Forum: Comparing Fuels for Harmful Side Effects
Close
Close
Close
55 comments
Anonymous Poster

Jet Pilots, Red-Outs, and High G-Turns

05/05/2008 9:26 PM

what remedial measure are taken by technician and scientists to prevent jet fighter pilot from blocking out or experiencing red-out due to high G-turn?

Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru
Engineering Fields - Environmental Engineering - New Member APIX Pilot Plant Design Project - Member - New Member

Join Date: May 2007
Location: Anywhere Emperor Palpatine assigns me
Posts: 2776
Good Answers: 101
#1

Re: safety measure

05/05/2008 11:25 PM

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.

__________________
If only you knew the power of the Dark Side of the Force
Reply
Power-User
United States - US - Statue of Liberty - Sworn to preserve and protect Engineering Fields - Nanoengineering - How tiny is it? APIX Pilot Plant Design Project - Member - Good idea. Engineering Fields - Engineering Physics - Engineering Fields - Energy Engineering - Energy in Transition

Join Date: Nov 2007
Location: Near DC, USA
Posts: 128
Good Answers: 15
#2

G-Force Incapacitation prevention

05/06/2008 12:13 AM

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.

__________________
“Truth is stranger than fiction, but it is because Fiction is obliged to stick to possibilities. Truth isn't.” – Samuel Clemens in Following the Equator, Pudd'nhead Wilson's New Calendar
Reply
Power-User
United States - US - Statue of Liberty - Sworn to preserve and protect Engineering Fields - Nanoengineering - How tiny is it? APIX Pilot Plant Design Project - Member - Good idea. Engineering Fields - Engineering Physics - Engineering Fields - Energy Engineering - Energy in Transition

Join Date: Nov 2007
Location: Near DC, USA
Posts: 128
Good Answers: 15
#3

Re: safety measure

05/06/2008 5:50 AM

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.)

__________________
“Truth is stranger than fiction, but it is because Fiction is obliged to stick to possibilities. Truth isn't.” – Samuel Clemens in Following the Equator, Pudd'nhead Wilson's New Calendar
Reply
3
Power-User

Join Date: Mar 2007
Location: South East of Las Vegas just far enough to see the lights but far enough to not hear the coins falling
Posts: 282
Good Answers: 8
#4

Re: Jet Pilots, Red-Outs, and High G-Turns

05/06/2008 11:17 PM

I have had the good fortune to work on and have flown in the F-15 aircraft numerous times. My experience with "g's" is this.

At 2-3 g's my head got heavier and sluggish. At 4-5 g's with my right hand on my right thigh I could not raise a finger. At 5-6 g's I could only allow my head to flop one way or they other. At 7.33 g's the 2" diameter G meter was not visible, tunnel vision was real bad. At 8 g's it was nightie night for a few seconds.

I have spent dozens of hours talking with pilots about this and here is what I learned.

Fighter pilots (in the last 10-15 years) have increased their physical fitness training to include G conditioning. Some aspects of that training were abdominal conditioning, neck strengthening (to assisted with the heavy helmet flopping around) and they all increase cardio to better saturate their blood with oxygen.

The inflatable G suit is on a slight delay behind the onset of G but there is a button that a pilot can depress to put the squeeze on prior to a high G load while they are "Grunting" and flexing their abdominals.

The answer is physical conditioning and a lot of high g practice. I know of an F-15 demo pilot that pulled 11.25 G's on a F-15A model during a Red Flag exercise and the aircraft was undamaged. The pilot however busted two blood vessels in his eyes. This high G was during a snap "trans sonic tuck" from super sonic the sub sonic speed while making a very hard turn.

Thanks for the chance to pull up great memories.

miketheboilerguy

__________________
Rule number one; Never ask a question unless you are prepared for an answer that you may not like.
Reply Good Answer (Score 3)
Power-User
United States - US - Statue of Liberty - Sworn to preserve and protect Engineering Fields - Nanoengineering - How tiny is it? APIX Pilot Plant Design Project - Member - Good idea. Engineering Fields - Engineering Physics - Engineering Fields - Energy Engineering - Energy in Transition

Join Date: Nov 2007
Location: Near DC, USA
Posts: 128
Good Answers: 15
#7
In reply to #4

Re: Jet Pilots, Red-Outs, and High G-Turns

05/07/2008 5:51 AM

MTBG: GA2U. Seems to me trainers are technicians. I assume you were a fit young man wearing a g-suit during the experience you describe. 8 G's is a serious load.

Nigh - the crash was a very short duration transient to 24 G. As to the design of the car, sounds like the way to go. Suppose it will eventually make it into regular vehicles?

__________________
“Truth is stranger than fiction, but it is because Fiction is obliged to stick to possibilities. Truth isn't.” – Samuel Clemens in Following the Equator, Pudd'nhead Wilson's New Calendar
Reply Off Topic (Score 5)
Guru
United Kingdom - Member - Old New Member

Join Date: Jul 2005
Location: South east U.K.
Posts: 3537
Good Answers: 92
#8
In reply to #7

Re: Jet Pilots, Red-Outs, and High G-Turns

05/07/2008 6:18 AM

Suppose it will eventually make it into regular vehicles?

Not so sure about that, considering the cost of an F1 car.

__________________
I didn't have a really important life, but at least it's been funny (Lemmy Kilminster 1945-2015)
Reply Off Topic (Score 5)
Guru

Join Date: Jul 2006
Location: Silicon Valley
Posts: 5356
Good Answers: 49
#15
In reply to #8

Re: Jet Pilots, Red-Outs, and High G-Turns

05/07/2008 11:51 PM

Vodka and cigarettes! I'm just sayin'...

__________________
"Perplexity is the beginning of dementia" - Professor Coriolus
Reply Off Topic (Score 5)
Power-User
Canada - Member - BC Born, Alberta Raised, Quebec (poutine) crazed... Engineering Fields - Aerospace Engineering - An airplane is just a bunch of beams... Hobbies - Model Rocketry - Had fun as a kid...fun stuff Hobbies - CNC - dreaming of cutting Engineering Fields - Control Engineering - PID ME!

Join Date: Aug 2006
Location: Montreal, CANADA
Posts: 368
Good Answers: 10
#10
In reply to #4

Re: Jet Pilots, Red-Outs, and High G-Turns

05/07/2008 9:59 AM

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

__________________
kkjensen
Reply
Guru
Hobbies - RC Aircraft - New Member Hobbies - Automotive Performance - New Member Hobbies - DIY Welding - New Member

Join Date: Jul 2007
Location: Fort Lauderdale Florida
Posts: 5708
Good Answers: 123
#12
In reply to #4

Re: Jet Pilots, Red-Outs, and High G-Turns

05/07/2008 12:35 PM

Thank you.

__________________
Bob
Reply
Guru

Join Date: Jul 2006
Location: Silicon Valley
Posts: 5356
Good Answers: 49
#5

Re: Jet Pilots, Red-Outs, and High G-Turns

05/07/2008 1:37 AM

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!

__________________
"Perplexity is the beginning of dementia" - Professor Coriolus
Reply
Guru
Hobbies - HAM Radio - CE3AM....4X4SW....CE3NSW

Join Date: Aug 2006
Location: Santiago Chile.
Posts: 845
Good Answers: 7
#22
In reply to #5

Re: Jet Pilots, Red-Outs, and High G-Turns

05/10/2008 10:35 AM

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.

__________________
Never trade luck for skill.
Reply
Guru

Join Date: Jul 2006
Location: Silicon Valley
Posts: 5356
Good Answers: 49
#23
In reply to #22

Re: Jet Pilots, Red-Outs, and High G-Turns

05/11/2008 3:00 AM

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!!!

__________________
"Perplexity is the beginning of dementia" - Professor Coriolus
Reply
Guru
Hobbies - HAM Radio - CE3AM....4X4SW....CE3NSW

Join Date: Aug 2006
Location: Santiago Chile.
Posts: 845
Good Answers: 7
#25
In reply to #23

Re: Jet Pilots, Red-Outs, and High G-Turns

05/12/2008 4:33 PM

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.

__________________
Never trade luck for skill.
Reply
Guru
United Kingdom - Member - Old New Member

Join Date: Jul 2005
Location: South east U.K.
Posts: 3537
Good Answers: 92
#6

Re: Jet Pilots, Red-Outs, and High G-Turns

05/07/2008 4:31 AM

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.

__________________
I didn't have a really important life, but at least it's been funny (Lemmy Kilminster 1945-2015)
Reply
Participant

Join Date: May 2008
Posts: 4
#9

Re: Jet Pilots, Red-Outs, and High G-Turns

05/07/2008 8:37 AM

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.

Reply Score 1 for Off Topic
Power-User

Join Date: Oct 2007
Location: S. California, USA
Posts: 279
Good Answers: 12
#11

Re: Jet Pilots, Red-Outs, and High G-Turns

05/07/2008 12:10 PM

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.

Reply Score 1 for Good Answer
Power-User
United States - US - Statue of Liberty - Sworn to preserve and protect Engineering Fields - Nanoengineering - How tiny is it? APIX Pilot Plant Design Project - Member - Good idea. Engineering Fields - Engineering Physics - Engineering Fields - Energy Engineering - Energy in Transition

Join Date: Nov 2007
Location: Near DC, USA
Posts: 128
Good Answers: 15
#13
In reply to #11

Re: Jet Pilots, Red-Outs, and High G-Turns

05/07/2008 1:24 PM

Good answer 2 U.

__________________
“Truth is stranger than fiction, but it is because Fiction is obliged to stick to possibilities. Truth isn't.” – Samuel Clemens in Following the Equator, Pudd'nhead Wilson's New Calendar
Reply Off Topic (Score 4)
Active Contributor

Join Date: Apr 2008
Posts: 13
Good Answers: 2
#35
In reply to #11

Re: Jet Pilots, Red-Outs, and High G-Turns

05/14/2008 1:26 PM

Sir, that is a P-82, not a P-52. It was made by joining 2 P-51's. For a good review of the P-82 (aka F-82 in it's last days), please see this web site: http://www.johnweeks.com/p82/index.html

Regards, valkyrie3610

__________________
The gap between theory and practice in practice is greater than the gap between theory and practice in theory.
Reply Off Topic (Score 5)
Power-User

Join Date: Oct 2007
Location: S. California, USA
Posts: 279
Good Answers: 12
#36
In reply to #35

Re: Jet Pilots, Red-Outs, and High G-Turns

05/14/2008 1:44 PM

valkyrie3610,

Thank you for the correction. I am just a just a poor typer. My dad flew the P51 and his base also had the P82. He has many stories as these early aircraft were dangerous and they had emergencies daily. One of my favorites:

Pilot to tower: Request landing instructions for straight in approach.

Tower: Why do you want a straight in approach. Do you have a problem?

Pilot: No, but my co-pilot's engine has failed and he's is all excited.

Reply Off Topic (Score 4)
Guru

Join Date: Jul 2006
Location: Silicon Valley
Posts: 5356
Good Answers: 49
#37
In reply to #36

Re: Jet Pilots, Red-Outs, and High G-Turns

05/15/2008 1:47 AM

Interesting about the P82! This is the first I've heard about it. Did it ever see action in WII?

__________________
"Perplexity is the beginning of dementia" - Professor Coriolus
Reply Off Topic (Score 5)
Active Contributor

Join Date: Apr 2008
Posts: 13
Good Answers: 2
#38
In reply to #37

Re: Jet Pilots, Red-Outs, and High G-Turns

05/15/2008 1:15 PM

No service in WWII, but it did see service in the early days of the Korean War.

__________________
The gap between theory and practice in practice is greater than the gap between theory and practice in theory.
Reply Off Topic (Score 5)
Guru
Hobbies - HAM Radio - CE3AM....4X4SW....CE3NSW

Join Date: Aug 2006
Location: Santiago Chile.
Posts: 845
Good Answers: 7
#39
In reply to #11

Re: Jet Pilots, Red-Outs, and High G-Turns

05/15/2008 10:24 PM

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.

__________________
Never trade luck for skill.
Reply
Guru

Join Date: Jul 2006
Location: Silicon Valley
Posts: 5356
Good Answers: 49
#40
In reply to #39

Re: Jet Pilots, Red-Outs, and High G-Turns

05/15/2008 11:16 PM

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

__________________
"Perplexity is the beginning of dementia" - Professor Coriolus
Reply
Power-User

Join Date: Oct 2007
Location: S. California, USA
Posts: 279
Good Answers: 12
#41
In reply to #39

Re: Jet Pilots, Red-Outs, and High G-Turns

05/16/2008 12:00 PM

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.

Reply
Guru
Hobbies - HAM Radio - CE3AM....4X4SW....CE3NSW

Join Date: Aug 2006
Location: Santiago Chile.
Posts: 845
Good Answers: 7
#42
In reply to #41

Re: Jet Pilots, Red-Outs, and High G-Turns

05/16/2008 6:58 PM

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

__________________
Never trade luck for skill.
Reply
Power-User

Join Date: Oct 2007
Location: S. California, USA
Posts: 279
Good Answers: 12
#43
In reply to #42

Re: Jet Pilots, Red-Outs, and High G-Turns

05/16/2008 8:58 PM

wangito,

I concede that I am have not flow in over 30yrs and that I have never flown a high performance aircraft. But I do remember that a properly executed barrel roll only puts a positive g-load on the aircraft. I was just confused by your original posting that described in great detail how to enter and exit the roll, but no mention of using ailerons.

But back to the original point. Your original beef with my posting is that you do not believe that it is possible for one pilot to experience +G's while the other is experiencing -G's. In my post I should have used the term aileron roll, but I erroneously said snap roll. I apologize to you and the community for my carelessness.

Now that I am hopefully using the right terminology, do you understand that it is possible for one pilot to experience +G's while the other is experiencing -G's when performing a simple aileron roll when flying a P-82 with its two cockpits?

Reply Off Topic (Score 5)
Guru

Join Date: Jul 2006
Location: Silicon Valley
Posts: 5356
Good Answers: 49
#45
In reply to #43

Re: Jet Pilots, Red-Outs, and High G-Turns

05/17/2008 3:12 AM

If you want the Red-Out, you'll have to talk to Ben Stein!

__________________
"Perplexity is the beginning of dementia" - Professor Coriolus
Reply Off Topic (Score 5)
Guru
Hobbies - HAM Radio - CE3AM....4X4SW....CE3NSW

Join Date: Aug 2006
Location: Santiago Chile.
Posts: 845
Good Answers: 7
#46
In reply to #43

Re: Jet Pilots, Red-Outs, and High G-Turns

05/17/2008 2:28 PM

Hello Snave.,

  1. Yes, a properly executed Barrel Roll, subjects the aircraft and the pilot to positive g's only.
  2. Same goes for properly executed Aileron Roll.
  3. Snap-Roll does not require the use of ailerons. The snap roll is a horizontal spin and is being executed just like a normal spin, stick all the way back, as the stall approaches, kick right or left rudder, maintain ailerons level. difference being that the stall in the snap-roll is a high speed stall versus slow speed stall in a normal spin and is pretty violent, hence the name "snap".
  4. I did not say that two pilots could not be subjected to two different SIGN g's. but in order to achieve that they will have to sit not side by side as in the P-82, but rather foot to foot meaning an angle of 180° between their heads. So when one flies up-right and is subject to +1g the other flies upside down and is subject to minus (-)1g. During a turn, one will be making an inside turn and will experience positive g, while the other Will make an outside turn and will experience a negative g.
  5. Have you ever seen such an airplane? I didn't. Again, flying the P-82 both pilot will always experience the same sign +or-g but possibly different g load levels.

Hope this clears the question..

Wangito.

__________________
Never trade luck for skill.
Reply Off Topic (Score 5)
Guru
Hobbies - RC Aircraft - New Member Hobbies - Automotive Performance - New Member Hobbies - DIY Welding - New Member

Join Date: Jul 2007
Location: Fort Lauderdale Florida
Posts: 5708
Good Answers: 123
#49
In reply to #46

Re: Jet Pilots, Red-Outs, and High G-Turns

05/19/2008 8:27 AM

And a properly executed garlic roll subjects me to heartburn.

__________________
Bob
Reply Off Topic (Score 5)
Guru

Join Date: Jul 2006
Location: Silicon Valley
Posts: 5356
Good Answers: 49
#44
In reply to #41

Re: Jet Pilots, Red-Outs, and High G-Turns

05/17/2008 3:07 AM

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

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

__________________
"Perplexity is the beginning of dementia" - Professor Coriolus
Reply
Guru
Hobbies - HAM Radio - CE3AM....4X4SW....CE3NSW

Join Date: Aug 2006
Location: Santiago Chile.
Posts: 845
Good Answers: 7
#47
In reply to #44

Re: Jet Pilots, Red-Outs, and High G-Turns

05/17/2008 3:35 PM

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.

__________________
Never trade luck for skill.
Reply Score 1 for Good Answer
Guru

Join Date: Jul 2006
Location: Silicon Valley
Posts: 5356
Good Answers: 49
#48
In reply to #47

Re: Jet Pilots, Red-Outs, and High G-Turns

05/18/2008 3:37 AM

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!

__________________
"Perplexity is the beginning of dementia" - Professor Coriolus
Reply
Power-User

Join Date: Oct 2007
Location: S. California, USA
Posts: 279
Good Answers: 12
#50
In reply to #44

Re: Jet Pilots, Red-Outs, and High G-Turns

05/19/2008 12:18 PM

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.

Reply
Guru
Hobbies - HAM Radio - CE3AM....4X4SW....CE3NSW

Join Date: Aug 2006
Location: Santiago Chile.
Posts: 845
Good Answers: 7
#51
In reply to #50

Re: Jet Pilots, Red-Outs, and High G-Turns

05/19/2008 2:45 PM

Hello Snave,

Excuse me for being inquisitive, but I am sure your insistence on the positive/negative issue is based on some info that I don't have. Can you give the link to where you read this? I am very curious.

Wangito.

__________________
Never trade luck for skill.
Reply
Power-User

Join Date: Oct 2007
Location: S. California, USA
Posts: 279
Good Answers: 12
#52
In reply to #51

Re: Jet Pilots, Red-Outs, and High G-Turns

05/19/2008 5:01 PM

Hello wangito,

I do not have an internet site to offer, but I did email my dad a WWII vet (8th Army) and USAF vet (graduation class of 49C). As a base commander, stationed state side during the Korean War, he had flown with the P82 and also debriefed the pilots. This is what he had to say:

I worked with F 82 in many interceptions which was called the twin Mustang. I had them come out to our radar site to beat up the base so the guys could see for them selves these planes and feel like they were in the Air Force as we were at Pacific Beach, WA. I put them on the base PA system so the guys could hear the pilots talk and get into the mood. We used them for base alert so it was like real. We had a cook in white who was hiding behind a log and the guys said. I just nailed the cook in white hiding behind a log. They were way below the radar sail so right on the deck and below hill at ocean level at the base at time.

The F 82 was hard to land as instead of 3 points on the landing gear, it had 4 points so some time would bounce back between the four wheels. Guys were careful not to roll too fast as not to black or red out each other. I was working with one (F-82) on an intercept when the pilot said he wanted to abort the mission. I asked why and he said his R/O (Radar Operator) wanted to come home as his engine quit.

Another twin engine aircraft that my dad is studying is the Bell Airacuda. He is sending me an article and after I get it I will be able to site another source that describes black out / red out. For the mean time my dad wrote ... the Bell Airacuda [article] talks about the lousy design and engineering problems it had. This plane had a twin engine pusher type design where the two gunners sat in the engine nacelle with the guns they fired. This was way out side of the center line so the gunners either blacked out or red out on a fast roll. Bail out was bad as it took 6 seconds to stop the props so the guys could bail out. This was long time for that stuff. You will see what a nutty plane this was. It was abandoned at Wright Paterson and just forgotten as a bad dream. I guess they finally scrapped the thing.

My dad also adds some interesting observations about the human body's reaction to G-forces. In a plane like a F 51 trainer or a T-33, the guy not flying would black out before the guy flying would as a passenger would not tense up as well as the guy flying. I remember a guy showing me how he made gunnery passes and I would always black out and not see what he wanted to show me and vise versa.

I will provide more if you are still not convinced.

Reply
Guru
Hobbies - HAM Radio - CE3AM....4X4SW....CE3NSW

Join Date: Aug 2006
Location: Santiago Chile.
Posts: 845
Good Answers: 7
#53
In reply to #52

Re: Jet Pilots, Red-Outs, and High G-Turns

05/20/2008 9:13 AM

Hi Snave.

Read your dad's mail carefully. He never said that one pilot would black-out while the other would red-out. Or maybe my English is failing.

  1. More than 1g (+ or -) loads will only happen in an accelerated flight.
  2. During a constant velocity at any speed there's 1g. and they both will have the same g. which is their own weight.
  3. In order to increase g-loads to more than one, be it plus or minus, you need to accelerate or decelerate. Increase your speed, lower your speed, pull Up,or down, turn, or any combination thereof.
  4. If both pilot are flying the same trajectory they will always be under the same g-loads. I have never seen an airplane where one pilot goes to war while the other at the same time in the same airplane flies back home...
  5. The difference in g due to different radius is very small. and again , it is the same sign g.

Sorry pal, you didn't convince me.

Wangito

__________________
Never trade luck for skill.
Reply
Guru

Join Date: Jul 2006
Location: Silicon Valley
Posts: 5356
Good Answers: 49
#54
In reply to #53

Re: Jet Pilots, Red-Outs, and High G-Turns

05/21/2008 2:25 AM

On the other hand, if we were talking a tandem UFO, then say no more!!! You could have aliens blacking-out, redding-out, even greening-out! Whoa!!! The possibilities are endless!!!

Did anybody get a peak at the Airracuda?! What a vomit-comet ride that must have been!!! "Hey I was just about to shoot that guy! Why'd ya turn?!"

__________________
"Perplexity is the beginning of dementia" - Professor Coriolus
Reply
2
Commentator

Join Date: Apr 2008
Posts: 73
Good Answers: 10
#14

Re: Jet Pilots, Red-Outs, and High G-Turns

05/07/2008 5:41 PM

Hate to rain on everyone's parade, but there is so much information on this subject on the internet and in encyclopedias etc that it is staggering. Our guest has already obviously read all that stuff. This leads to the more than obvious question as to whether our "guests" question is truly innocuous. They obviously were looking for personal experience that goes beyond what they already have available to them. In the interests of the national security of whatever countries you all may be from, it is best to stay as far away as possible from questions such as these. Sorry "guest". The loads of information you already have available on the web should be more than enough if you are simply curious.

Reply Good Answer (Score 2)
Power-User

Join Date: Oct 2007
Location: S. California, USA
Posts: 279
Good Answers: 12
#18
In reply to #14

Re: Jet Pilots, Red-Outs, and High G-Turns

05/09/2008 11:35 AM

Dear PhysicsProf,

I agree that there is much information available on the internet and in text books, but you make some wild assertions.

You state "Our guest has already obviously read all that stuff." and then conclude with "They obviously were looking for personal experience that goes beyond what they already have available to them." I have read and re-read the guest posting and do not see how you read your observation into the question and then draw the conclusion that you do. I read "…experiencing red-out due to high G-turn?" and observe an error in his question as a "red-out" is caused by pulling negative G's while a "high G-turn" provide positive G loading and draw no conclusions but suspect that (1) guest has not done their homework, (2) English is not a native language, or (3) guest is careless with details.

Professor, I hope you teach better science (conclusions based on careful observation) than you have demonstrated here. I think that the rain is on your parade as you are the one that is wet.

Reply Score 1 for Good Answer
Guru

Join Date: Jul 2006
Location: Silicon Valley
Posts: 5356
Good Answers: 49
#19
In reply to #18

Re: Jet Pilots, Red-Outs, and High G-Turns

05/10/2008 12:02 AM

Oh, dude! Don't talk like that! I mean they're out there, man! They're after us, man! Ya can't be too careful these days! For all we know they might be reading our minds right now! Oh no, man!!! I can feel 'em!!!

That's my best Dennis Hopper impersonation.

__________________
"Perplexity is the beginning of dementia" - Professor Coriolus
Reply
Guru
Hobbies - RC Aircraft - New Member Hobbies - Automotive Performance - New Member Hobbies - DIY Welding - New Member

Join Date: Jul 2007
Location: Fort Lauderdale Florida
Posts: 5708
Good Answers: 123
#20
In reply to #19

Re: Jet Pilots, Red-Outs, and High G-Turns

05/10/2008 12:34 AM

Do you hear the voices too?

__________________
Bob
Reply Off Topic (Score 5)
Guru

Join Date: Jul 2006
Location: Silicon Valley
Posts: 5356
Good Answers: 49
#21
In reply to #20

Re: Jet Pilots, Red-Outs, and High G-Turns

05/10/2008 1:00 AM

Only when I'm in Dennis Hopper mode.

__________________
"Perplexity is the beginning of dementia" - Professor Coriolus
Reply Off Topic (Score 5)
Anonymous Poster
#26
In reply to #18

Re: Jet Pilots, Red-Outs, and High G-Turns

05/12/2008 9:49 PM

Ouch! Who put the tack in that extremely WET diaper of yours Snave? Are you really THAT naive? Truly?! Honestly?! More evidence that this place isn't worth my time!

Reply Score 2 for Off Topic
Power-User

Join Date: Mar 2007
Location: South East of Las Vegas just far enough to see the lights but far enough to not hear the coins falling
Posts: 282
Good Answers: 8
#31
In reply to #26

Re: Jet Pilots, Red-Outs, and High G-Turns

05/13/2008 9:55 AM

That is why you have not registered?

__________________
Rule number one; Never ask a question unless you are prepared for an answer that you may not like.
Reply
Power-User
United States - US - Statue of Liberty - Sworn to preserve and protect Engineering Fields - Nanoengineering - How tiny is it? APIX Pilot Plant Design Project - Member - Good idea. Engineering Fields - Engineering Physics - Engineering Fields - Energy Engineering - Energy in Transition

Join Date: Nov 2007
Location: Near DC, USA
Posts: 128
Good Answers: 15
#32
In reply to #18

Re: Jet Pilots, Red-Outs, and High G-Turns

05/13/2008 11:53 AM

The issue raised by PhysicsProf is the propriety of releasing personal experience publicly, when that information might gage or reflect the system or subsystem capability of front line tactical aircraft. It is a valuable point.

This is a public forum and one can never know who is reading it.

Just for appreciation.... considerable effort by the intelligence agencies of all governments goes into gathering information from open sources - like newspapers, magazines and web sites. It is a bit like panning for gold. Each piece of information found may be only like a flake of yellow with very little value, but put a few thousand of them together and you have valuable nugget. (Check out Open Source Intelligence: A Strategic Enabler of National Security for a good brief (3 pages) on the subject.) When one discusses first hand experience with, or special knowledge of one of these high-tech systems it can be like handing out the nugget!

For those who do not understand this, it is OK. It is most likely you have no cause for concern.

__________________
“Truth is stranger than fiction, but it is because Fiction is obliged to stick to possibilities. Truth isn't.” – Samuel Clemens in Following the Equator, Pudd'nhead Wilson's New Calendar
Reply Off Topic (Score 5)
Associate
Belgium - Member - New Member

Join Date: Jun 2007
Posts: 28
#16

Re: Jet Pilots, Red-Outs, and High G-Turns

05/09/2008 5:22 AM

Dear all

What are de limits and priciple of red-outs? (all the blood flows to the head, why a delplation of oxigen?)

Are the g-suits for red-out?

what are the limits a person can bear in red-out? any data?

The F16 is limited at 9g is an F15 not limited?

Thanks

Reply
Anonymous Poster
#17
In reply to #16

Re: Jet Pilots, Red-Outs, and High G-Turns

05/09/2008 10:07 AM

the F-16 is a fly by wire computer limiting system that will only allow the acft. to pull G's as conditions allow. the F-15 is only limited to the pilots ability to handle the load.

Reply
Power-User

Join Date: Oct 2007
Location: S. California, USA
Posts: 279
Good Answers: 12
#24
In reply to #16

Re: Jet Pilots, Red-Outs, and High G-Turns

05/12/2008 12:26 PM

Farman - I extracted these words from the Encyclopedia Britannica:

"Negative acceleration stress occurs when the direction of acceleration is from feet to head. This causes a slight displacement of the internal organs in the abdomen and chest and a rush of blood to the face accompanied by the feeling of congestion. As the acceleration increases the congestion increases and throbbing pains are felt throughout the head. When the…"

AND "...and there is a gritty feeling under the eyelids because of swelling in the small blood vessels. There may be temporary loss of vision or all objects may appear red; this latter condition is known as "red-out." The mental confusion that develops at high accelerations may lead to unconsciousness."

Because a G-suite applies pressure to the outside of the body to push the blood up from the legs and abdomen toward the head, they only help pilots withstand positive G forces for a longer period of time before experiencing brown, grey, then a full black-out. I do not believe that there is any device to help offset the effects of negative Gs. Readers, correct me if I am wrong.

Reply
Guru
Hobbies - HAM Radio - CE3AM....4X4SW....CE3NSW

Join Date: Aug 2006
Location: Santiago Chile.
Posts: 845
Good Answers: 7
#27
In reply to #24

Re: Jet Pilots, Red-Outs, and High G-Turns

05/12/2008 10:14 PM

:...You wrote: "correct me if I am wrong"

OK than :

"G" suit partially stops blood streaming. by "embracing" the large blood vessels. Works both ways, Centrifugal and centripetal.

Wangito.

__________________
Never trade luck for skill.
Reply Score 1 for Good Answer
Guru

Join Date: Jul 2006
Location: Silicon Valley
Posts: 5356
Good Answers: 49
#28
In reply to #27

Re: Jet Pilots, Red-Outs, and High G-Turns

05/12/2008 11:50 PM

They have these new, big, puffy hats that squeeze the blood out of the brain to prevent red-out. I think they've been testing them in Washington for the last eight years.

__________________
"Perplexity is the beginning of dementia" - Professor Coriolus
Reply Score 1 for Off Topic
Guru
United Kingdom - Member - Old New Member

Join Date: Jul 2005
Location: South east U.K.
Posts: 3537
Good Answers: 92
#29
In reply to #28

Re: Jet Pilots, Red-Outs, and High G-Turns

05/13/2008 4:42 AM

Would they help on a pub crawl?

__________________
I didn't have a really important life, but at least it's been funny (Lemmy Kilminster 1945-2015)
Reply Off Topic (Score 5)
Guru
Hobbies - HAM Radio - CE3AM....4X4SW....CE3NSW

Join Date: Aug 2006
Location: Santiago Chile.
Posts: 845
Good Answers: 7
#30
In reply to #28

Re: Jet Pilots, Red-Outs, and High G-Turns

05/13/2008 8:40 AM

Yah, I have heard about it...

After the proof of concept and R+D are all done they promised to use it on almost all of the world's leading heads. I just hope it will not to late for some million or more Burmese. However I know it will, as these guys, even when their blood flow is perfectly OK they still can't think.

Wangito.

__________________
Never trade luck for skill.
Reply
Power-User

Join Date: Oct 2007
Location: S. California, USA
Posts: 279
Good Answers: 12
#33
In reply to #27

Re: Jet Pilots, Red-Outs, and High G-Turns

05/13/2008 4:53 PM

wangito,

Correction appreciated. I gave you a vote because you taught me something.

Thanks,

Reply Score 1 for Off Topic
Guru
Hobbies - HAM Radio - CE3AM....4X4SW....CE3NSW

Join Date: Aug 2006
Location: Santiago Chile.
Posts: 845
Good Answers: 7
#34
In reply to #33

Re: Jet Pilots, Red-Outs, and High G-Turns

05/13/2008 5:25 PM

You're very welcome sir.

Wangito.

__________________
Never trade luck for skill.
Reply Score 1 for Off Topic
Guru
United Kingdom - Member - Old New Member

Join Date: Jul 2005
Location: South east U.K.
Posts: 3537
Good Answers: 92
#55

Re: Jet Pilots, Red-Outs, and High G-Turns

07/28/2008 5:41 AM

I was watching the Red Bull air race on tv at the weekend. The speed and G force for each run was displayed and the fastest competitors were pulling in excess of 11G when pulling up to turn in order to run the course in reverse. They were doing this 3 times within about 5 minutes which seems amazing.

__________________
I didn't have a really important life, but at least it's been funny (Lemmy Kilminster 1945-2015)
Reply
Reply to Forum Thread 55 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

Anonymous Poster (2); bob c (3); DVader1000 (1); Farman@skynet.be (1); kerry@spd4u.com (1); kkjensen (1); miketheboilerguy (2); Nigh (4); PhysicsProf (1); Snave (9); v1sor (5); valkyrie3610 (2); vermin (12); wangito (11)

Previous in Forum: How Much Green and at What Cost?   Next in Forum: Comparing Fuels for Harmful Side Effects

Advertisement