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View Full Version : Why is it not safe to bail out at high speeds?



Afromike1
04-04-2009, 02:38 PM
This if for real life, im wondering why its not safe to bail out at high speeds. Ive come along this question by watching the d-day episode of Band of Brothers and playing IL2.

Is it just a safety issue or is it physically impossible to bail out at high speeds? Is it like tackling through a brick wall when the air currents get that fast?

DKoor
04-04-2009, 03:36 PM
I don't think it is unsafe to bail out at high speed per se, it is safe but under certain conditions (those conditions mostly don't include ww2 airplanes tho http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif ).
However damaging the tail of your plane with your head and other collisions between our body and the aircraft structure doesn't sound very appealing.
Chance of that happening is increased with speed.. on lower speed you should be able to 'unglue' yourself from aircraft easier (from the air stream).
And yes, many reports say that it is virtually impossible to bail out on high speed because force needed to counter the powerful air stream that envelops our plane is higher than the force of our muscles; you probably wont be able to pull your body from the cockpit at all. Sometimes when you lose wing or aircraft is in some kind of wild spin (high speed) force that glues you to your seat is excessive...

Owlsphone
04-04-2009, 03:44 PM
Going from calm air to 400mph air on your body can't be too fun.

Viper2005_
04-04-2009, 04:07 PM
Drag = Q*Cd*S

Q = 0.5*roh*V^2 = Dynamic Pressure

Indicated Air Speed may be thought of as Q^0.5 for the purposes of this discussion.

A skydiver in free fall will descend at about 120 mph give or take.

So 120 mph IAS produces a drag force on a person which is approximately equal to their body weight.

It therefore follows, thanks to the V^2 term, that 240 mph IAS would produce a drag force of about 4 times your body weight, whilst 360 mph would crank that up to 9 times.

In IL2, it is impossible to escape at speeds greater than 500 km/h IAS, which is about 310 mph. This is almost certainly an optimistic upper limit, as if we take that 120 mph as a baseline, it implies that the pilot is able to force himself free of the aircraft despite being pinned by an aerodynamic drag force equivalent to about 6.7 times his body weight.

Of course, the aerodynamic force is acting roughly perpendicular to the direction in which the pilot is trying to move, so the coefficient of friction between pilot and aeroplane is of importance.

However, because the pressure applies to the pilot is so large, at these sort of dynamic pressures it is extremely unlikely that a real pilot would escape IRL.

***

Of course, as has already been pointed out, it's quite likely that if you're abandoning the aeroplane then something significant has either fallen off or is on fire, which further complicates matters.

If the aeroplane is out of control and moving fast then quite substantial g forces may be developed, which may either aid or oppose the pilot's escape attempts.

The risk of collision with the aircraft structure is ever-present, especially at high speed, where the pilot will accelerate at perhaps several g relative to the aeroplane due to aerodynamic drag.

Of course, another important issue is that parachutes have deployment limits. If you somehow manage to get yourself out of the aeroplane at 300 knots then you will have to wait until you've slowed down to something more reasonable like 150 or so before pulling the D-ring, as otherwise the deployment loads may exceed the strength of the parachute, causing it to burst. Of course, at the limits of parachute strength, the deceleration will be extremely violent and most uncomfortable, especially if the straps are not correctly adjusted.

DKoor
04-04-2009, 04:17 PM
The best albeit quite innocent compared to our situation, would be to try to put your arm out of your car at 150km/h. Not a pleasant thing to do. We can only imagine what happens when you try to do that at 600km/h.

Now taking into account what the guys above me already pointed out, it's a true miracle that so much people lived to tell the tale by bailing out from their crates in WW2. I imagine going fast on lower altitudes while trying to bail out of damaged plane is almost guaranteed death.

Waldo.Pepper
04-04-2009, 04:42 PM
1.) It is almost impossible to bail out at high speeds - as the force of the air will keep the pilot from getting out. (This is partly the reason that ejection seats were invented - to overcome this, and allow an egress.)

2.) Early ejection seats often caused broken and dislocated arms and legs. As the rapid exposure to the speed of the air would more often than not pull and twist the pilots limbs into highly unnatural positions. The more modern seats cinch the limbs down during the ejection process.

Zeus-cat
04-04-2009, 06:21 PM
When I was in the U.S. Air Force I worked in a lab that studied escaping aircraft at high speeds. It becomes more dangerous as the speed increases. Above 500 or 600 mph, without a modern ejection seat, and you may as well ride the aircraft into the ground. Your odds of survivung an ejection at those speeds approaches zero.

People often die due to limb flail during high speed ejections. The arms or legs get caught in the windstream and get thrown back with such force that the arteries are severed and the pilot bleeds to death by the time they hit the ground.

Tully__
04-04-2009, 07:21 PM
Even at reasonable WW2 speeds (250-300mph) some pilots suffered broken or dislocated limbs as a result of bailing out.

ImMoreBetter
04-04-2009, 07:56 PM
In the stories I've read and heard of pilots bailing out, they often note that it took them two tries to bail out.

The first attempt, they were blasted in the face with several hundred mph winds that would nearly rip their helmet/oxygen mask off. They didn't expect that.

Bailing out is a lot more violent than this game (or any game I've seen) makes it seem.

- The aerodynamic forces could keep the canopy from opening.
- The pilot could collide with a part of the plane.
- The wind forces could twist/break/dislocate limbs.
- The aerodynamic forces could force the pilots down into their seat.
-I would imagine the feeling would be similar to being punched in the face... but all over your body simultaneously.

I once saw a guncam clip of a pilot managing to get out of his plane. He tumbled in a very unpleasant manner. One of those 'there were people in those planes' moments.

julian265
04-05-2009, 02:45 AM
There was an air racing pilot (no doubt someone else will remember his name) who bailed out of a modified Corsair at supposedly 400mph, his parachute straps were partially torn, and panels had blown out of the canopy. Had had back and leg injuries too.

I wonder what proportion of bail-out attempts had a successful ending.... Any stats around?

Xiolablu3
04-05-2009, 06:44 AM
Its just impossible to get out of the seat at very high speeds.

GH_Klingstroem
04-05-2009, 06:56 AM
http://www.youtube.com/watch?v=NtB-XKFxEJY

here is the link of the guy bailing out of his Corsair!

x6BL_Brando
04-05-2009, 08:24 AM
Bailing out is a lot more violent than this game (or any game I've seen) makes it seem.

I took a long-range deflection shot at a D3A the other day, from a fronter-quarter merge position. He was in level flight, I was climbing up, and my very short burst hit his engine and stopped it dead. The pilot bailed immediately and struck the left horizontal stab, which then broke off from the impact. First time I ever saw that effect. I was left with no doubt that the pilot must've been a bloody mess too, but it was time to break and check my tail.

Some things are best left to the imagination anyway.

B

killersquad1960
04-05-2009, 10:40 AM
It can be a variety of reason your killed after bail out.
Plane is shot up s bad half your wing rip clean off so your spinning out of control.
Thus you bail out, your head hits any part of the plane, canopy is stuck or when opens hits you killing you instantly, if your on fire I try to level the plane if I have control slow speed and then bail out

raaaid
04-05-2009, 10:55 AM
actually according bernuoillin the fastest the biger vacuum and the easier to jump

Zeus-cat
04-05-2009, 01:54 PM
Originally posted by raaaid:
actually according bernuoillin the fastest the biger vacuum and the easier to jump

I'm feeling adventurous today. Explain yourself raaaid.

Insuber
04-05-2009, 02:48 PM
Raaid is right in a sense.

Bernoulli :

p + v^2/2g + z1 = cost

hence higher the speed of the air above the exposed cockpit, lower his pressure. But as soon as the pilot is exposed to the airflow he is subject to the aerodynamic pressure as said above, which glues him as a fly to the cockpit edges.

In his book"A Willingness to Die", Kingcome describes the shock of bailing out at high speed, you may want to read it.

Ins

ash1976
04-05-2009, 03:18 PM
Would there also be some inherent danger in the speed you hit/are pulled into the airstream and the stresses this would apply to the parachute when opened? Given these were not the days of hyper strength nylon/CF weave risers, etc?

oh, and http://forums.ubi.com/images/smilies/88.gif - just seen Owlsphone sig for the first time - quality effort!!

Insuber
04-05-2009, 03:23 PM
Originally posted by ash1976:
Would there also be some inherent danger in the speed you hit/are pulled into the airstream and the stresses this would apply to the parachute when opened? Given these were not the days of hyper strength nylon/CF weave risers, etc?

oh, and http://forums.ubi.com/images/smilies/88.gif - just seen Owlsphone sig for the first time - quality effort!!

The pilots were instructed to let their speed stabilize, once jumped out, to the free-falling human body, some 200 km/h, before pulling the cord. Kingcome info. If a pilot panicked and pulled it at high speed, the parachute would rip to pieces, it's easy to understand.

Ins

M_Gunz
04-05-2009, 04:11 PM
By Bernoulli the moving *air* outside would be at lower pressure *perpendicular to the direction of that motion*
than non-moving-in-that-direction *air* inside. The thing is that once you open the canopy the air inside gets
sucked out until air inside is also at lower pressure, it doesn't get re-supplied as fast as it's drawn out.

The pilot would have to overcome the pressure of air moving above to get out, it is *very high* in the direction
of travel.

Applying and mis-applying *parts* of science doesn't work except to fool people, even the ones concocting the stories.
It's easy to do. Just *ignore* what you don't want, can't remember, never learned or isn't convenient.
In the end you have your rhetoric and can even make smoke-blowing charts even though the result is *wrong*.

I'm still waiting on those "it's possible" energy-producing perpetual motion machines, anti-gravity machines,
room-temperature fusion devices and production cars that get 80+ mpg on water alone.

Gazzahh
04-05-2009, 05:01 PM
It was a high speed bailout that rendered Hans Joachim Marsielle unconcious when he hit the tail section and he fell to his death in September 1942. Probably the most sucessfull figther pilot of ww2 with 156 kills against Western pilots

Insuber
04-05-2009, 05:21 PM
Originally posted by M_Gunz:
By Bernoulli the moving *air* outside would be at lower pressure *perpendicular to the direction of that motion*
than non-moving-in-that-direction *air* inside. The thing is that once you open the canopy the air inside gets
sucked out until air inside is also at lower pressure, it doesn't get re-supplied as fast as it's drawn out.

The pilot would have to overcome the pressure of air moving above to get out, it is *very high* in the direction
of travel.

Applying and mis-applying *parts* of science doesn't work except to fool people, even the ones concocting the stories.
It's easy to do. Just *ignore* what you don't want, can't remember, never learned or isn't convenient.
In the end you have your rhetoric and can even make smoke-blowing charts even though the result is *wrong*.

I'm still waiting on those "it's possible" energy-producing perpetual motion machines, anti-gravity machines,
room-temperature fusion devices and production cars that get 80+ mpg on water alone.

Of course the pressure in the cockpit will reach equilibrium in a split second, nature likes it... but why this aggressivity ? Ate spicy food ? http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif


Ins

JarheadEd
04-05-2009, 09:06 PM
Really,.. It seems like it hurts more the faster you go. (Reads story) Huh! It seems sensationalism has been reigned in. This story used to have a part in it where the throttle physically stuck and he bailed supersonic. Still a good read, and poor, poor maintenance. All the seat cartridges were still at MCAS El Toro having never been put back in following the acceptance inspection.

From Here (http://www.cloudnet.com/%7Edjohnson/records.htm)


Best [Worst] Ejection - On 18 June 1963 VMF(AW)-323 "Deathrattlers" began Operation Green Wave, transfer of 18 F-8E's from MCAS El Toro, CA. to NAS Atsugi, Japan. The first leg of the flight was to be from MCAS El Toro to MCAS Kaneohe, HI. with aerial refueling from Marine KC-130's. Two aborts resulted from the first six aircraft and one was lost from the next six. Maj. D.K.Tooker ejected when his Crusader caught fire after a fuel cell erupted from overfilling during tanking from a KC-130. Tooker ejected seconds before the F-8 exploded and was fortunate to be rescued by a destroyer-escort.

The squadron's fortunes improved no more on Day Two. Like Tooker's aircraft, the plane of 1st Lt Judkins fell victim to failure of the tanker's automatic cutoff. Filled beyond capacity, the F-8's main fuel cell burst, an identical failure to Tooker's. Fuel was observed by other pilots to be coming from several fuselage vents, the chin scoop and the tailpipe and the engine abruptly flamed out. Judkins quickly prepared for an air start. He brought the throttle to cut off, extended his RAT, hit the igniters at about 10 percent rpm, noted the Exhaust Temperature (EGT) gage climb and engine rpm increasing. At about 30 percent rpm his EGT needle passed the yellow band and went through the red line and pegged at 1000 degrees. Warnings came from his wingman saying "Jud, you're on fire. Get out of there". Judkins positioned himself and called "Mayday" and pulled the face curtain.

He saw the fully extended yellow felt lining of the face curtain (no instructions) but nothing happened. He pulled the alternate firing handle between his knees; the canopy remained in place and the seat still refused to fire. Now in a 60 degree dive, he jettisoned the canopy and prepared for a manual bailout. He knew that noone had bailed out of a Crusader successfully but there was no alternative. He unstrapped the seat belt and shoulder harness and disconnected the g-suit; trimmed the flaming Crusader as well as possible at about 225 KIAS and stood on the seat with both arms guarding his face. He was sucked out, half expecting to hit the sharp leading edges of the tail. He missed the tail and was free falling. That was the good news. The bad news came when Jud pulled the D-ring. He heard a loud pop but his fall remained unchecked. Glancing up, he saw the 24 ft canopy wrapped in its shroudlines. Desperately, Judkins shook the risers, trying to deploy the canopy but to no avail. He looked down, saw his F-8 impact point and realized there was nothing more to do. His next sensation was that of being cold. Judkins never remembered hitting the water but he surfaced, coughing and retching. His Mae West had inflated but he was tangled in his chute. Despite excruciating pain, he cut himself free. Most of his survival gear had been ripped away on impact but he settled down to wait for his rescue. His wingman was the first to fly over. Later, a C-130 circled at low altitude and Jud was able to wave to the crew. After about an hour, a C-130 dropped a large life raft and some supplies, all of which were unreachable by the downed pilot. Another drop by a C-130 almost was a direct hit on Jud but he was unable to reach that raft also. After about one more hour, a Coast Guard HU-16 Albatross dropped another large life raft with a long yellow line attached. Jud was able to grab the yellow line and draw the raft to him but he was unable to get in the raft. Judkins knew that the sea was far too rough for the HU-16 to land. He lashed himself to the raft and settled down to wait for help. After about 2 1/2 hours, the minesweeper USS Embattle (AM-434) picked him out of the sea although he does not remember the actual rescue. He was transferred to the Los Angeles (CA-135) from which a helo took him to the hospital ship USS Haven which was permanently docked in Long Beach.

Judkins injuries included multiple fractures of both ankles, a severed tendon, fractures of his pelvis and seventh vertebrae and partial collapse of one lung. In addition to numerous cuts and bruises, his intestines and kidneys had ceased functioning. His temperature was down to 94 degrees. The doctors agreed that Jud would have died had not his spleen been removed following a car wreck during flight training.

Judkins returned to flight status after six months in the hospital. He immediately returned to flying the F-8 and, on the first flight after his "bailout", made numerous plug-ins on a 90 minute refueling flight. Cliff Judkins is now retired from flying with Delta Airlines and resides in Marietta, GA.

Jud was a first rate pilot and Marine Officer. He is a member of the Crusader Association, Tailhook Assn and the Marine Corps Aviation Association.

Semper Fi, Lynn Williams

M_Gunz
04-05-2009, 09:42 PM
Originally posted by Insuber:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
By Bernoulli the moving *air* outside would be at lower pressure *perpendicular to the direction of that motion*
than non-moving-in-that-direction *air* inside. The thing is that once you open the canopy the air inside gets
sucked out until air inside is also at lower pressure, it doesn't get re-supplied as fast as it's drawn out.

The pilot would have to overcome the pressure of air moving above to get out, it is *very high* in the direction
of travel.

Applying and mis-applying *parts* of science doesn't work except to fool people, even the ones concocting the stories.
It's easy to do. Just *ignore* what you don't want, can't remember, never learned or isn't convenient.
In the end you have your rhetoric and can even make smoke-blowing charts even though the result is *wrong*.

I'm still waiting on those "it's possible" energy-producing perpetual motion machines, anti-gravity machines,
room-temperature fusion devices and production cars that get 80+ mpg on water alone.

Of course the pressure in the cockpit will reach equilibrium in a split second, nature likes it... but why this aggressivity ? Ate spicy food ? http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif


Ins </div></BLOCKQUOTE>

Read it the way you want.
I thought you'd been around long enough to have seen the some of gems Raaaid and some others have thrown out here
along with the hoorah whenever one supports an agenda or just "that's why I got shot down!".

Oh well, it's not like any of us read everything posted. I sure don't.

raaaid
04-06-2009, 08:25 AM
then what about making a hole on the floor of the plane as the canopy expels to be sucked up?

would it work?

bernuilli blah blah...

Outlaw---
04-06-2009, 08:33 AM
Originally posted by raaaid:
then what about making a hole on the floor of the plane as the canopy expels to be sucked up?

would it work?

bernuilli blah blah...

Only a few aircraft were sealed/pressurized. There were holes all over them.

--Outlaw.

raaaid
04-06-2009, 08:45 AM
nono i mean something like this:
http://i40.photobucket.com/albums/e222/raaaid/06-04-09_153501.jpg

M_Gunz
04-06-2009, 09:29 AM
For structural reasons perhaps? The air would have to come up right under the pilot to push
him out and up or it's just more of the same trapping him into tighter space and able to do less.
Not to mention what happens if the hatch opens when you don't want.

Or what happens right after the pilot gets sucked into an airstream headed right onto the tail?
Better to drop straight down anyway but problems there as well, and that was done in some cases.
A lot of things were tried and a lot more were abandoned in the planning stage.
But these were people who got to the next step and saw it was no good.
As usual, designs "evolved" and the fittest survived by being copied or adopted.

This is why I ask where the perpetual motion machines are.
If any ever really worked then they would be everywhere.

raaaid
04-06-2009, 09:35 AM
the police oil keeps them secret?

i have several teachers of engines that say the water engine is kept hidden by the petrochemicals,energy from matter vibration?

if they kill woman and children worldwide to keep oil in business why would they let a nerd ruin them

M_Gunz
04-06-2009, 12:13 PM
LOL! Everything but making it work! Why not is simply that it can not.

Blah-blah-blah oil police. There are people here making the scam and selling books.
What they show is a couple minutes something runs, it is hydrogen from ACID and METAL.
Guess what the REAL cost per distance is? More than gasoline. And no oil police stop
anyone from making or changing cars yet with lots of people doing so. For years people
try and so far nothing really working, no big savings and nobody stopping those who try.

It's just a way to separate money from gullible people who believe in wishes and nonsense.
If anyone had something REAL, there would be many everywhere. Oh wait, there are. They
are called "cars" and some even more advanced than others. But none run on water alone or
use water alone to achieve extreme mileage. So far those are all hoaxes, but YOU can make
the big change and all you gotta do is make it work. I'm waiting but I won't hold my breath.

The price of gas makes government look bad. Anything that can work gets support.
Politician who can announce such a great thing would be easy winner. Oil police? BS.
Elections change just because of economy. With alternative to gas, the next Bush brother
would be president now, McCain would not have run. Instead, promise of change won.

snafu73
04-06-2009, 12:28 PM
Is there any conspiracy theory he doesn't believe?

http://forums.ubi.com/images/smilies/10.gif

Afromike1
04-06-2009, 01:16 PM
Originally posted by snafu73:
Is there any conspiracy theory he doesn't believe?

http://forums.ubi.com/images/smilies/10.gif

I think 9/11 was set up by gypsies.

raaaid
04-06-2009, 03:44 PM
oh i dont buy conspiracy theories i make my own

like toilet paper having adicted substances, like it goes not throug sanity controls

if you think toilet paper is not adictive try one day without it, it fullfills all symptons of an addiction

now try to find this gold idea out of this forum

Bobbo_Tabor
04-06-2009, 04:14 PM
Originally posted by raaaid:
oh i dont buy conspiracy theories i make my own

like toilet paper having adicted substances, like it goes not throug sanity controls

if you think toilet paper is not adictive try one day without it, it fullfills all symptons of an addiction

now try to find this gold idea out of this forum

I think you touched bottom with this toilet paper comment. http://forums.ubi.com/images/smilies/winky.gif

"high speed bailouts" and toilet paper, now there is a combination. Clearly I am not the only person here with a bad diet. http://forums.ubi.com/images/smilies/blink.gif

snafu73
04-06-2009, 05:18 PM
Originally posted by raaaid:
oh i dont buy conspiracy theories i make my own

like toilet paper having adicted substances, like it goes not throug sanity controls

if you think toilet paper is not adictive try one day without it, it fullfills all symptons of an addiction

now try to find this gold idea out of this forum


Next, you'll be telling us you are addicted to oxygen. Either that or you'll have a eureka moment and recognise the difference between a necessity and an addiction.

M_Gunz
04-06-2009, 10:39 PM
How long can he go without hemp is more to the point.

raaaid
04-07-2009, 04:44 AM
oh i just let the conversation evolve

my point is toilet paper doesnt go through sanity control which would allow a crook to put adictive substances on it to sell more his brand, anus is very absorvent, you could put any drug in your anus and would be like putting it into your stomach

i only avogue for toilet paper going through sanity controls, i think im being sensible here

edit:

a necesity is something natural: eating drinking sleeping sex...

but toilet paper is not natural

i still recall the times when i was a child and DID NOT USE toilet paper at all, no problem at all, in fact my anus is designed by trillion years evolution to work by itself without the need of toilet paper

the problem is that once you try toiltet paper youll be hooked for life, if you stop using it the cravings will be really bad

its a really strong adiction that moves trillions and destroys whole forests cause most humanity is hooked to this and dont even know

Tully__
04-07-2009, 06:30 AM
Back on topic please, or if you must continue start over in the Off Topic forum.

raaaid
04-07-2009, 06:37 AM
oh sorry i dont think its worthy it to start over

do you think my drawing with the door in the bottom would work for easy ejection at high speeds?
http://i40.photobucket.com/albums/e222/raaaid/06-04-09_153501.jpg

Outlaw---
04-07-2009, 09:30 AM
Originally posted by raaaid:
oh sorry i dont think its worthy it to start over

do you think my drawing with the door in the bottom would work for easy ejection at high speeds?


[edit - scratch the following]
No, because there would not be enough differential pressure. Even if it were a full vacuum's worth of differential that would only be 14.7 psi and that's if you were very low.
[end edit]

I thought you were drawing the trailing edge of the wing, not a trap door type setup. The force generated by the deflected air mass would, of course, depend on density and speed but my initial guess is that it would not be worth the effort. The door would have to be unbelievably strong and thus heavy. Also, it would cause a large pitching moment that might even make it harder to get out. It looks like you expect it to launch the whole seat like a modern day ejection seat but I don't see how it could generate enough force for that. It would not be as effective as a good ejection seat, thus, it would still require effort on the part of the pilot. I would rather have to do it all myself rather than have a partial system that might bump me out before I was ready.

Not a bad idea to throw around though.

--Outlaw.

JuHa-
04-08-2009, 01:00 PM
Some pilots reported exiting from the cockpit simply by:
1) leveling the plane
2) opening/ejecting the canopy
3) opening the harness, oxygen mask etc.
4) with legs, pushing the stick fully forward

Of course, it isn't always possible to push enough negative G's.

And assuming the pilot gets out of the plane with a lot of speed - it'll take some time (altitude) for him to slow down enough to deploy the chute. And as per some of the earlier posts, if one just opens up the limbs into 'X' position, they may suffer bad injuries -> unable to pull the D-ring.

Furthermore, if you deploy your chute from wrong bodily position or a bad spin, it's more than likely that the chute won't open properly. So a proper body position is highly desirable before opening the chute -> jumper has to slow down first.