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Helicopter Ejection Seats - via Main Rotor area

12/16/2007 2:48 AM

The actual speed of Helicopter Main Rotors are actually quite low in RPM.

Could a successful Vertical ejection seat be made, which ejects the pilot of the helicopter safely through the arc made by the main rotor blades?

If so, discuss whether you think this could be a practical solution, for certain helicopter situations.

I note that there is a side ejection Helicopter Ejection Seat already in commercial usage, but that may not be good in some circumstances, refer:

http://en.wikipedia.org/wiki/Ejector_seat

and

http://en.wikipedia.org/wiki/Kamov_Ka-50

I am reminded of Anthony Fokker's invention, the synchronised machine gun, fitted to the Fokker E aircraft back in 1914-1915.

This system of Anthony Fokker's, ensured the propeller blades, travelling at high RPM, could never strike the propeller blades, through the arc of the propeller which the gun fired those bullets.

Kind Regards from far away.....

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#1

Re: Helicopter Ejection Seats - via Main Rotor area

12/16/2007 4:08 AM

I think there are other forces that need to be considered. If the helicopter looses its tail rotor, it goes into a spin centered around the main rotor, and to autogyro one down you have to nose it over. You may be launched in the right direction but with the other forces in play you may still get whacked by the main blade. I would rather get launched straight ahead.

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#2
In reply to #1

Re: Helicopter Ejection Seats - via Main Rotor area

12/16/2007 5:20 AM

Thank you possien for your suggestion.

The Design Committee are grateful, and have incorporated your advice immediately.

The method chosen for reliability at low cost is similar to a modified JATO bottle, which has controlled output and directional firing, if the tail rotor drive or rotor is lost.

That means the thorny and perennial problem of rear rotor failure in single main rotor helicopters has been overcome at last.

The Awards Committee thereby presents you with this fine along with this useful sign in recognition of your efforts.

All suggestions are gratefully received.

Thank you once again.....

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#3

Re: Helicopter Ejection Seats - via Main Rotor area

12/16/2007 8:17 AM

I don't think the absence of the rear rotor will have a great effect. The speed of the main rotor(s) in relation to the body will be known.

What I am concern about is the speed required to fit a object 100 times longer than a bullet in the gap between blades.

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#4
In reply to #3

Re: Helicopter Ejection Seats - via Main Rotor area

12/16/2007 8:47 AM

"What I am concern about is the speed required to fit a object 100 times longer than a bullet in the gap between blades".

Yes, Hendrik, that is one problem the Design Committee hope that the lateral thinkers here can overcome.

I'm sure that the proper application of a litre or two of brainpower along with plenty of elbow-grease, and a dash of effort, most of these trivial problems can be mastered.

Remember: Good things take time", or for a Chef: "Good things take thyme", and for the Doctor: "Thyme heals all wounds"......

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#5

Re: Helicopter Ejection Seats - via Main Rotor area

12/16/2007 9:47 AM

I think it could work for a two seat attack style helicopter. Might be hard to do for a passenger machine like a troop transport.

As a part of off shore training workers actually practice ditching a helicopter. The class climbs into a mockup of a helicopter cabin, and they dump it upside into a swimming pool so you can practice getting out of your harness, open the door, and swim out all under water. This is done so that off shore workers will be less likely to panic in the event that they are involved in a real ditch.

I know that was a little off topic, but the point is that a water ditching is expected to be survivable, so for that industry your ejection seat is not as necessary. Seems like a military application.

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#6

Re: Helicopter Ejection Seats - via Main Rotor area

12/16/2007 11:04 AM

This system of Anthony Fokker's, ensured the propeller blades, travelling at high RPM, could never strike the propeller blades, through the arc of the propeller which the gun fired those bullets.

This is what came to mind for me as well. As sychronization was needed, they used an interrupter gear which allowed pilots to fire through the moving propeller. Problem was that it is not perfect. At times a bullet would still strike the blades thus the need for armored blades. The ejection seat and main rotor would need to be very well repeatable.

I really don't see much else short of a blow away canopy device applied to the main rotor itself, in which it is freed from the fuselage prior to ejection. However the notion of having my lift source entwined to such a system seems a bit uncomfortable. But I guess jet fighters have that all pretty well worked out. If a jet canopy erroneously comes off at Mach II that would not be good either.

cr3

good question.

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#7

Re: Helicopter Ejection Seats - via Main Rotor area

12/16/2007 11:42 AM

Been done. The Kamov Ka-50 was the first helicopter to be fitted with an ejection seat.

http://en.wikipedia.org/wiki/Ejector_seat

The simple solution is not unlike a canopy in the F-16. You get rid of it before you leave the cockpit. The Kamov have explosive bolts on the rotors and blow them a fraction of a second before the seat leaves the airframe.

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#8
In reply to #7

Re: Helicopter Ejection Seats - via Main Rotor area

12/16/2007 2:33 PM

Thank you Anonymous Hero,

You get top marks because you checked the references, so pass through here:

It does look as if you are the first respondent to actually read the reference I gave in my question, to the Kamov Ka-50 helicopter.

So...now you have located the answer, is there any way the vertical ejection seat system can be designed and used, WITHOUT blowing those main rotor blades off the support shaft ?

Kind Regards.....

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#9
In reply to #8

Re: Helicopter Ejection Seats - via Main Rotor area

12/16/2007 4:01 PM

Yes, but why?

Use a braking system on the rotor assembly, to reduce the RPM's on the rotor to the point where a locking pawl can be engaged, at a position where the gap in the rotor blades is directly above the canopy.

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#10
In reply to #8

Re: Helicopter Ejection Seats - via Main Rotor area

12/16/2007 5:43 PM

Uhhh. I take offense to that statement.


cr3

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#11
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Re: Helicopter Ejection Seats - via Main Rotor area

12/16/2007 5:56 PM

Thanks! Why not give me a "Good Answer" rating. ;-)

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#15
In reply to #11

Re: Helicopter Ejection Seats - via Main Rotor area

12/16/2007 10:01 PM

Hello again, Anonymous Hero,

Thanks! Why not give me a "Good Answer" rating. ;-)

I would gladly give you a "Good Answer" rating.

But a "Good Answer" Rating is not given just because you looked up the references given, and we wonder whether you were just

The Awards Committee has given you top marks, for the effort you made in "Checking up on the question asker", and some Graphical recognition too.

Good Answer Credits are given for original research, or a best technical answer.

Otherwise every member would get a"Good Answer" credit for each Post they make, because the Standard of answers given at CR4 is creditable = Worthy of Credit.

Anyway, if you were given a "Good Answer" credit right now, you would have one more than me.

However, because of your earnest (Who knows what an ear nest is ?) plea, a special meeting of the Awards Committee sat earlier today, and by unanimous vote decided to give you this marvellous personal auto-filling water-cooler , which they are certain you will appreciate, along with a horizontal bar, attached with invisible skyhooks, just so you can end up with muscles looking like this chap

Kind Regards.....

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#16
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Re: Helicopter Ejection Seats - via Main Rotor area

12/16/2007 10:08 PM

Arg! You are tough, but fair!

I accept the water cooler with infinite gratitude and praise your wisdom and insight. ;-)

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#40
In reply to #16

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 10:05 AM

Also 10 = 9 +1 ! (You still need to catch the cat though). Actually I considered blowing the blades but it seemed a bit far fetched and risky. Who says you have to go up in an ejector seat - can you drop down if flying at sufficient height ? There is of course an alternative (which I think Jeb did) ; http://www.cbsnews.com/stories/2007/12/12/earlyshow/leisure/celebspot/main3609758.shtml

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#12
In reply to #8

Re: Helicopter Ejection Seats - via Main Rotor area

12/16/2007 6:11 PM

Well, answering your question about not blowing off the rotors, I would guess it is possible. That will depend on the maximum speed of the rotors for the specific aircraft, but in theory you could time the escape like they do for bullets in prop driven fighter aircraft.

Theory is one thing, but I still think that blowing the rotors yields the highest probability of survival. Plus, you want to get that seat out as fast as possible.

Also, even under the best circumstances, the ACES II ejection systems only have a 92% success. There are fatalities during the ejection process and it is not perfect. Look up Martin-Baker website, too.

So, escape system design is going to look for the highest probability of survival as the primary criteria. Getting the rotors out of the way seems like the least risk to me.

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#32
In reply to #12

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 7:53 AM

"Well, answering your question about not blowing off the rotors, I would guess it is possible."

It's possible as long as we don't use Microsoft© software to control synchronization.

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#13
In reply to #8

Re: Helicopter Ejection Seats - via Main Rotor area

12/16/2007 7:35 PM

Okay. I know a little about the subject so I ran some rough numbers. First, seats pop out at somewhere between 12g to 20g (beyond 20g pretty much insures spinal fracture). They fire a rocket that has a burn time of about .5 seconds. In .15 seconds they have a velocity 100 feet per second and have cleared about 15 feet at 20g.

That would be the point about where I would expect the rotors to be. So, lets calculate the amount of time you have if a 30 foot rotor was moving at a rotational velocity of 550 rpm. I think they go even faster, but I want a round number. At that rpm on a 4-blade rotor you have a window of about .03 seconds!

That is not a lot of time for escape if my numbers are anything close to reality. At the speed of the seat you will have moved at best 24 feet at 20g and 5 feet at 12g. At the slow speed that would not be quite enough to sneak through the blades with a perfectly timed exit.

Also, when your seat goes off you want to deploy the parachute as soon as possible. Typically, unless the airspeed is above 200 knots, they are deployed upon seat ejection. If the speed is above 250 knots the drone shute is fired and the actual parachute is not deployed until an altitude criteria is met (typically below 15K feet).

Since helicopters generally are low altitude, shute deployment is required as early as possible to allow it to open.

The shute poses a great entanglement risk in itself. So the blades are a high risk.

Another issue is timing. The rocket packs and the pre-boost engine are not very predictable for the time window we have. There are a number of factors at play here. Pilot weight, ambient temperatures, and vehicle dynamics are just a few. This is why the acceleration varies from 12 to 20g. You also have variance in the propellant itself and the ignition system.

I bet it could be done, but it would be so much cheaper and easier (not to mention safer) to blow the rotors and be done with it.

So my last question is, why would you not want to blow the rotors? Is there something or reason that we would want to not do that?

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#14
In reply to #13

Re: Helicopter Ejection Seats - via Main Rotor area

12/16/2007 9:10 PM

Nice!

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#17
In reply to #13

Re: Helicopter Ejection Seats - via Main Rotor area

12/16/2007 11:24 PM

Hello once again, Anonymous Hero, and we can see you are persistently dogged in your thinking.

It will be OK providing you don't get into this situation

"So my last question is, why would you not want to blow the rotors? Is there something or reason that we would want to not do that?"

OK, the scenario is a helicopter, flying over La Brea tar pits, and a sudden emergency exit needs to be made, because the helicopter is going down.....into the largest tar pit.

There are many tourists and children around, mobile gelato salesmen pedalling and peddling their wares.

You see the scenario now: The helicopter pilot needs to eject vertically and safely via the arc of the top rotor, his "chopper" is going to crash into a tar pool, and he does not want any debris (rotor pieces etc) injure any bystanders, tourists, children or gelato salesmen.

If the helicopter crash lands in the tar pit, it and its entire contents are going on a one-way trip to join the trapped extinct dinosaurs bones in that tar pit.

Therefore the only safe exit from the doomed helicopter is also the only way out: Vertically upwards in the ejection seat, then afterwards a gentle drift safely to the ground

To make it easier, calculations may be done on the following designs:

  1. 2-bladed main rotor
  2. 3-bladed main rotor
  3. You have done the approximations on the 4-bladed main rotor
  4. 3-bladed twin contra-rotating main rotor
  5. 4-bladed twin contra-rotating main rotor
  6. Others you may choose

Extra marks are given for neatness, of course

If you have any

Kind Regards....

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#30
In reply to #17

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 6:48 AM

Well, your hypothetical scenario would most likely end with the pilot going down. Historically, pilots tend to do the heroic thing when innocent lives are at stake.

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#111
In reply to #17

Re: Helicopter Ejection Seats - via Main Rotor area

12/22/2007 8:06 PM

An idle thought or two:

Assuming the tar is reasonably cool, isn't a pool of viscous gunge the best place for a lump of metal to land? Syrup doesn't seem to splash much.

Taking the area overflown by these craft, what is the total area of tar-pits, compared with the area overflown (ok, you've got to factor in flying time)? (i.e. what is the probability?)

Late coming to this thread, so I may be out of line.

Happy Christmas.

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#112
In reply to #17

Re: Helicopter Ejection Seats - via Main Rotor area

12/22/2007 8:46 PM

"Therefore the only safe exit from the doomed helicopter is also the only way out: Vertically upwards in the ejection seat,"

"then afterwards a gentle drift safely to the ground."

Don't you really mean: "then afterwards a gentle drift safely to the tar pit"?

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#48
In reply to #8

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 12:33 PM

If you're not going to arrest the rotor, and you're not going to remove it, then you have a very brief time period in which the ejection seat can pass through the disc of the rotors.

[Quick RPM Math: 20ft radius ~= 6m radius; circumference = 12pi meters; Speed of sound ~= 330 m/s ... 360 m/s depending on density, temperature, etc.; Max revs per second for a 6m radius rotor, in air of 330m/s speed of sound, is about 8.75 RPS.]

A three blade rotor, moving at 8.75 revs/second, gives 1/(3*8.75) seconds ~= 0.038s between one blade passing overhead and the next.

For an ejection seat of, say, 5ft height (includes height for the top of the pilot's helmet, etc.), the seat must be travelling at ~= 131 ft/sec (~40m/s) to pass through the blade disc without touching either the one before or the one after.

Say the disc is 5ft above the top of head of the pilots.

Assuming a constant thrust on the ejection seat, then:

s = ut + 1/2 at2

and

v = at

apply.

u (initial vertical velocity relative to the rotor disc) is 0; s = 5 ft.

5 = 1/2 vt = 1/2 . 131 t

t = 5*2/131 ~= 0.076 seconds.

That's 3/40ths of a second to accelerate to 131 ft/s (40m/s), or...

Ejection seat acceleration ~= 40 / 0.076 ~= 524 ms-2.

We know that g ~= 10ms-2. So to work, the ejection seat would be applying roughly 52g to the pilot. To my knowledge the human body can handle 5 or 6 g, and maybe up to 10 or 12 - but 52g? I doubt it.

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#51
In reply to #48

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 2:17 PM

Nice analysis! Your numbers confirm my earlier attempt, but I gave a vertical distance of more like 15 feet, which was too generous I am sure, but proves a point.

Burn times for fighter aircraft seats are a two-stage. Stage one clears the rails and gets the seat above the canopy rail where the second stage rocket kicks in. Total thrust time is about 1/2 second to get the seat far enough from the aircraft (about 600 feet) before the burn is complete.

I wrote earlier that typical G forces for seats run 12 to 20G. Beyond 20G the risk of injury goes up quickly and 25G will pretty much guarantee spinal injury. There is always a potential of appendage injury and the US made ACES II seat has a 8% fatality rate upon ejection, so it is a pretty violent way to deplane!

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#52
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Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 3:28 PM

I say forget the whole idea of ejecting humans and/or rotors, and lets rethink the problem. The absolutely top priority here is to preserve the life of helo crew and secondarily to salvage the aircraft if possible.

How about an air bag system similar to that used with the Mars rovers? In an emergency, jettison the rotors (if not over inhabited area) then activate the airbag. Actually, a dual airbag system might be better. One for the crew and a second for the helo. They would work in tandem.

If over an inhabited area initiate a relatively slow stoppage of the rotors such that they don't disentigrate. Otherwise deploy airbag(s) as usual. JMHO

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#53
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Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 3:33 PM

uh hum.....#44

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#54
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Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 3:35 PM

Touche!

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#55
In reply to #52

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 4:18 PM

Try working some numbers for your case. Helicopters range from 3200 lbs for small ones to 22,000 for some of the larger transports. Most fall closer to 10,000 lbs.

Imagine dropping a loaded Hummer from 200 feet except that the airframe is considerably less ridged and you have an engine that weighs thousands of pounds running loose (after it shears its mounts) inside with fuel!

Even at a terminal velocity of a few hundred miles per hour that is an enormous amount of energy to absorb. For comparison, the Pathfinder weighed almost 1,800 lbs (and that includes the heat shield, retros, etc, that are jettisoned before the probe hits the surface, so the weight is a good bit less) and was dropped from a height of about 100 feet after retros slowed it down enough that it hit the surface at about 40 mph.

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#57
In reply to #55

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 6:00 PM

Perhaps another trip to the old drawing board.

Suppose, after slowing the rotors a "little" we have the crew (which has become encased in a suitable restraint/airbag system) initiate "Bungee 1", a suitably designed bungee cord arrangement that will lasso the tip of a rotor (which has precut grooves for just such an occasion) and thus gently "sling" the crew clear of the aircraft. After clearing the danger area, we may even fire a parachute.

Of course this doesn't address the issue of salvaging the aircraft but perhaps it might salvage the crew.

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#59
In reply to #57

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 10:47 PM

How about a Kevlar capsule that just ejects right through everything! The hell with it. If ya' hit a blade who cares, your out of the thing!

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#61
In reply to #52

Re: Helicopter Ejection Seats - via Main Rotor area

12/18/2007 12:48 AM

At any rate, if one does succeed in creating a viable helicopter ejection seat, do not forget to yell, "So long, suckers!!!" Just before you deploy.

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#134
In reply to #48

Re: Helicopter Ejection Seats - via Main Rotor area

12/26/2007 9:25 PM

Just saw a special about a guy who pancaked an F-14 during an air show and lived through what was figured to be 75 g's when he hit the deck. He was busted from shoulder blade to pelvis, but lived. They sent in the physicists to study him! No one could believe he was alive, as the reported life expectancy record was set around 32-38 g's, tops.

The pilot was on the show talking about it! Discovery channel, of course.

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#18

Re: Helicopter Ejection Seats - via Main Rotor area

12/16/2007 11:55 PM

Blow the rotors off, but make sure they drag the escape capsule out when blown.

Plus when the rotors are blown and pull the escape seat, or capsule away from the aircraft body, since they will flail around above your head for a bit, after that cut loose on the down arc of flailing and trigger the parawing shute, and hope for the best.

Nano tech wires and so on will help it become universally adopted, I'm sure, for every seat.

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#19

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 12:06 AM

Just to be open to all directions of vertical how about a ejection seat that goes down first then jetos off to the side and up to level to eject the drogue chute? that way no problem with the rotor blades.

joshua

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#20

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 12:23 AM

Isn't this how they slice salami? All things considered, I'd rather be ejected out the side or bottom.

Vic Morrow, hope you're doing well wherever you are!!!

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#21

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 12:30 AM

What is the point? When helicopters fail, they often fail fast. Helicopters have a huge number of "critical parts/ assemblies". That is, the loss of one of these critical units results in instant failure. That is why in Vietnam, most fixed wing pilots were officers, but a great many helo pilots were warrants. They were expendable. Unless you are going to wire the helo to electonically sense a failure and automatically eject the occupants (possibly against their will, and would not be accepted by the pilots) it will often be too late. Next question, what helos would you equip with this unit? The day of the attack helo is ending, most carry some cargo and a lot of people. Would you eject the pilots and leave the rest to fend for themselves? Lastly, you could go google what sort of vertical "G" the human body can take, calculate acceleration at some safe level below that point and figure out how long it would take for a seat to pass throught the arc of a rotor. I think you will find that if it were possible, it would had been done. Why not go to www.martin-baker.com and ask them? They invented the technology.

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#22

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 12:52 AM

Ok, your worried about blowing the rotors off and injuring some people in the crowd, and the possible law suits that will ensure (I guess)

Then you eject safely from the helicopter (by whatever means) now no one is in control, what is going to stop it from hitting the "innocent" people at that stage in time? then there is a sudden gust of wind, it tips over, clips a tree and the flying debris from the rotors kills some in the crowd of onlookers.

You blow the rotors off and they hit the spectators, ok, you stop the rotors with a disc brake on the drive shaft, then you have to decel them so they don't get ripped from the mounts, and go spinning off and kill those same spectators.

But what happens first? does the ship get stopped in flight so when the emergency system activates, and there is no more lift, the helicopter falls vertically?

Not sure if its been done, but what about blowing the drive shaft for the rotors so they release by their own thrust, not blowing the rotors that will go off in a random direction, that shaft has a "keeper" that will restrain the rotor section from travelling too far, and then jettisoning a set of parachutes so everything just floats to the ground, or a wing type, so it can be steered safely to the ground like the NASA lifting body that was designed for the Space station emergency evac pod?

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#23

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 1:04 AM

Not likely, unless you were further away from the hub, where there would be a large enough space for a long enough period of time, but the acceleration needed to propel you through that tiny window of time would probably kill you as fast as the rotor blades hitting you would. The synchronized bullets shooting through the propeller are not passing close to the hub, but further out, where their window of opportunity for safe passage is much larger.

Best bet would be to first get rid of the rotor blades - quick release, explosive bolts, whatever means necessary to get them out of your desired path, then pop out any direction or speed you want. Even when skydiving, you don't want to pull your reserve chute until you first get rid of the main, otherwise all you end up with is 2 tangled chutes over your head and an extra second or two to impact.

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#25
In reply to #23

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 1:23 AM

What about "dead man's curve" which is where the altitude and the speed is not enough to land the helicopter dead stick.

If you're not within "dead-man's-curve," you can land the copter using auto-gyration.

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#24

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 1:17 AM

Use the rotor lift to pull you out (unless horizon 900 off or more) of the cockpit, release rotor to fly away from you, then blow it into fragments. Inherently complex. Most Choppers crash at under 200ft? (memory I think) No time to auto gyro, Parachute is useless unless rocket assist is employed.

Blow rotors, JATO cabin and passengers to altitude, deploy shute, guide large para-foil to suitable landing.

2cts from

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#26

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 2:39 AM

The interrupter gear used on the Fokker E was not fool proof and often bullets nicked the propeller! It's not so much if the proposed ejector seat would work but, who the f***ing hell would want to test it!!!

While commissioning a wind turbine in N.Ireland I was asked to test the nacelle emergency exit (a type of McNeil's descender) from a height of 80 meters in horizontal snow. All I can say is that my answer means that I'm still alive!

"A common mistake people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools."

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#31
In reply to #26

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 7:52 AM

No matter how safe and "idiot proof" an aircraft may be, there is always some ingenius idiot who will find a way to punch a hole in the ground with it.

Now I remember why I never got a helicopter rating. Picks nose.

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#27

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 3:44 AM

We have not talked about "through-the-floor" ejection yet! The problem with THAT idea is obivious! A way could be designed to quickly turn the helo UPSIDE DOWN, thus putting the floor of the helo UP! This would give a clear, obstruction free ejection. Just a wild thought! James

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#29
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Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 4:23 AM

Yep, wild thought alright. Roll rate. A helo is a big gyroscope and resistes rapid movements. How are you gonna turn it over in less than a second? Even our best fighter planes have a roll rate of about 720 degrees per second at best manuvering speeds. How are you going to get a hovering helo that has a substantial part of it's mass rotating about a plane to suddenly do a 180 degree roll and maintain altitude?

Tom

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#28

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 4:05 AM

As you don't wish to 86 the rotors, I must assume that you wish to reuse the helicopter. Does the same desire extend to the pilot and crew? If no, the question is meaningless. If Yes, then the question boils down to one of medical technique - perhaps a reverse CAT scan would be in order.

They're called "choppers" for a reason, you know.

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#33

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 8:43 AM

Why not the parachute for the helo and crew, you don't often hear that the helo crashes because of fire on board, just loss of control or power.

Blow the rotors and fire a parachute for the entire helo.

Maybe you can shoot this down too!

Dan

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#35
In reply to #33

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 9:43 AM

They do this for small aircraft, called ballistic recovery system. There are experiments with larger aircraft (commercial jets).

The big premise with this system is having enough altitude to engage the system and get the chute open in time to be effective. Forward velocity is an important component for these systems to work.

Many ejection seats have a zero-zero capability, and the technology is there. Ballistic recovery requires altitude, which is not always the case for rotary aircraft which typically work at much lower altitudes an low forward speeds.

Still, it is a better idea to save both aircraft and crew if you can reliably deploy a chute and find a way to do it at altitudes below 50 - 100 feet and open!

For military applications a missile will result in catastrophic loss of the vehicle and usually a significant fire. That is not a typical failure mode for civil aircraft.

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#44
In reply to #35

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 11:30 AM

Yeah I was thinking of the ballistic system too. Something I had drawn up it the late 80's and am still a bit sore about. As for low altitude, what about something like this....

...here

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#34

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 9:42 AM

Kudos on the blown rotor blades idea. They did that on a helicopter in the James Bond movie "Golden Eye".

My thought is instead of blowing the blades off causing the potential for collateral damage, why not have a mechanism that locks the rotor hub when an ejection capsule is fired. Have you ever seen those new table saws that can detect within thousandths of a second if your finger touches the blade while its spinning, and can drop the blade down below the deck before injury can occur? They stop the blade by essentially driving it into a large block of aluminum. Now, imagine something not unlike a circular saw blade on the rotor shaft. Initiating an ejection would trigger an explosive charge which could drive a block of aluminum to the blade and stop the rotor dead. Yes, obviously there would have to be more engineering involved to ensure the rotor blades and engine mounts could withstand that sudden change in momentum, but to me these seem somewhat trivial to find a solution for.

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#36
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Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 9:46 AM

I don't know the mass of a rotor system, but it must be pretty hefty. Even a titanium pin the size of your arm is going to get sheared off!

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#56
In reply to #34

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 5:03 PM

Methinks said block of metal would be very heavy to withstand being smaked into by a rotor blade - and weight and aircraft are not good friends!

Further, if the aim is to stop the rotor (not shear the blades off the rotor head) then most likely the blade roots would have to be beefed up to survive the impact with the block'o'metal.

Hmm, now we have a high inertia rotor system that suddenly wants to rotate around the block'o'metal: that most likely will try to rip the motor out of its housing...

Regarding blowing the blades off and the collateral damage they might cause - I suspect that the relative additional collateral damage caused by rotors landing apart from the crashing body of the aircraft (and the landing ejection seats) is sufficiently small as to cause military planners to be uninterested...

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#65
In reply to #56

Re: Helicopter Ejection Seats - via Main Rotor area

12/18/2007 1:18 PM

Perhaps I was a bit hasty in suggesting that the rotor motion stops completely. It would be sufficient to use such a machanism to slow the rotor blades down enough to time an ejection safely and without compressing the pilot into goo.

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#37

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 9:52 AM

My personal take is that the speed needed, with safety margins above and below, that the injected person would need to achieve in the short distance before the blades would probably mean that they could kiss their "A**E" goodbye from inside their body, due to the almost sudden acceleration....!!

So you don't need to synchonise, they will be dead anyway.....!

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#38

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 9:54 AM

I think we need to ditch this idea of ejection through the rotors! It would take a lot of time for the main rotor to completely clear the top of the helo before ejection could take place. It would be easier for a computer to put the helo in a hard roll, kill the power to the rotor, and activate the ejector seat in that order. The only thing the pilot would need to do is pull an ejection handle, and the computer could do the rest. I just dont see any other way because of the sheer size and mass of a spinning rotor! Bottom ejection (with rocket motor like on the fighter aircraft) would work. James

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#39
In reply to #38

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 10:04 AM

How about a charge that blows the rotor off first?

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#42
In reply to #38

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 10:52 AM

"...because of the sheer size and mass of a spinning rotor!"

As was pointed out earlier, that is one huge gyroscope! Roll rates would be painfully slow.

Another issue with the idea is that the body does not handle lateral acceleration very well at all. Lateral acceleration displaces organs and typically ruptures the aorta. You only need to look at crash data/autopsies for side impact accidents to see this. Ejecting sideways is not an option and you have the issues with extremities flailing in the process.

Negative G (discharging the seat downward) causes brain aneurisms when there is a sudden rise in blood pressure in the skull.

The human body is essentially a large sack of fluid and fluid dynamics during the ejection process must be considered.

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#43
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Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 11:15 AM

Q : In a disaster scenario how many seconds do you have ? Would it be enough to activate a chair mechanism that tilts the thing 90o and then......

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#41

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 10:38 AM

If we are truly to pursue this idea of 'survival of the fittest', this entire question should be rejected. When one boards such a device as a helicopter, he *should* undertand the risks :)

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#45

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 11:46 AM

Ok This might be stupid but what the hell. Since you are abandoning the ship why not stop the rotor altogether at time of ejection. Ship is a lose anyways so why take the chance of endangering the crews life with complicated timing? Develope a positive lock of the main rotor blade to allow safe ejection thru the blades. Or even simpler eject blades to allow unobstructed ejection.

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#50
In reply to #45

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 2:06 PM

Stopping the blades and main rotor and drive shaft would be impossible in a few seconds. The builtup of inertia and other forces are just too great to stop a rotor in a few seconds. Now , as ejecting blades as an idea, maybe explosive bolts could seperate the blades from the rotor. (much like the SRBs seperate from the shuttle during launch) James

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#46

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 12:30 PM

I don't know if anyone has posted this, but look at No2 ( and I'd be having a severe case of number twos !) ; http://www.ejectionsite.com/ejectfaq.htm

ooh, nice - http://www.army-technology.com/projects/ka50/

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#47

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 12:32 PM

Sparky,


What about the potential for eliminating (blasting off) the rotor just before blasting off with the ejection device?

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#49

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 1:28 PM

HELECOPTER EJECTION SEATS

I REMEMBER BEING IN DESIGN CLASS AND ONE OF THE CLASSMATES ASKED A SIMILAR QUESTION BASED ON THE SAME PROPRLLER TO MACHINE GUN TIMING ON FIXED WING AIRCRAFT.

THE ANSWER IS SIMPLE; WOULD YOU WANT TO BE THE TEST DUMMY?

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#58

Re: Helicopter Ejection Seats - via Main Rotor area

12/17/2007 10:09 PM

It has been tried - Not with too much success. to say least, very complicated.

But think about it, Who gets to sit on the ejection seat? Obviously the pilot. and than maybe the co-pilot, what about the passengers? if you talk about military helicopter, saving the VIPs on board only, would be against most militaries code of conduct, (well not all), If MEDIVAC, than are you going to kill the patients?, and what about the paramedics? Doctors?. Another point, A Martin-Baker ejection seat for a combat aircraft, is well over 2-3 million dollars each. an Apache crew of 5 will add up 15Million dollar to the price tag. No chicken shi%&$....And what about the added weight. Side ejection? never heard about it, but it's nonsense.... With helicopter low altitude flying, you will most likely have no enough altitude to make a safe landing, and what about if the helicopter is about to land sideways, will you shoot the pilot straight into the ground?

Instead, other methods have been tested and employed. The most successful one being the "over the rotor" chute system, which could be deployed by almost anyone of the fighting crew or designated persons on board. The main advantage being the fact that the chute will cause the helicopter to make a belly landing which would be the safest landing position, and without almost any forward speed, especially if the main rotor keeps on turning, which will cause dangerous tumbling. In case of sufficient altitude remaining, after emergency occurred, the main rotor break can be activated to stop gyroscopic effect especially in the case of a tail rotor emergency. Cheap reliable, and most of all no VIP treatment. And I (as a helicopter pilot,) believe makes a lot more sense, and wins hand down...

Wangito.

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#60
In reply to #58

Re: Helicopter Ejection Seats - via Main Rotor area

12/18/2007 12:39 AM

The rules may have changed but in 1980 when repelling from a chopper if they get a red light on the control board they cut the ropes. SOP

Seemed kind of harsh but I was to be on the rope.

Brad

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#62
In reply to #58

Re: Helicopter Ejection Seats - via Main Rotor area

12/18/2007 3:27 AM

Your points all make very good sense to me too. Sounds (almost) perfect! I see little chance of a problem with correct deployment....

Happy Christmas.

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#63
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Re: Helicopter Ejection Seats - via Main Rotor area

12/18/2007 5:54 AM

Actually, several new airplane designs are also incorporating chutes. (BRS, Ballistic Recovery System). While not always save the aircraft, They already saved few lives. The most famous one was of a pilot flying solo, that suffered a heart attack, landed safely,totally un conscious when he ran out of fuel , has been taken to a hospital and survived the ordeal.

Wangito.

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#64

Re: Helicopter Ejection Seats - via Main Rotor area

12/18/2007 7:01 AM

Oh no. Not me. No. I just won't do it. Spare me. Aaaaaaargh! <Splutter>

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#66
In reply to #64

Re: Helicopter Ejection Seats - via Main Rotor area

12/18/2007 5:18 PM

That rug you snuggle up in - it could be fashioned into a sort of parachute and packed on top of the main rotor. With some cunning anti twist roping, when disaster happens .... whooosh... Petes rug saves the day ! They might even let you squat in a nice warm Helicopter for your donation.

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#109
In reply to #66

Re: Helicopter Ejection Seats - via Main Rotor area

12/21/2007 6:21 AM

Stuff that! Are soles cobblers' stock-in-trade? <Wheeze, cough, cackle>.

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#110
In reply to #109

Re: Helicopter Ejection Seats - via Main Rotor area

12/21/2007 7:23 AM

Here's a handy tip for when the Sally Army soup kitchen runs dry. Being near Tilbury docks it may be of help ;

http://members.tripod.com/thesalvationnavy/history/archive.html

I'm noted for my sensitivity ! Why is it that we just don't get corrugated cardboard anymore ? Much better than all that foam packing - eco friendly and it wraps around the trouser legs easier.

Happy X-mas Pete, wherever you are aboding !

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#67

Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 12:29 AM

I still think that for any helicopter, and any commercial jet for that matter, we should be thinking of a massive ejection of the pilot and passenger compartment. The only reason why this wasn't developed 20 years ago is that it's cheaper to pay off dead-people's relatives than to do the R&D that it would take to make this possible.

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#68
In reply to #67

Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 1:51 AM

Vermin,

I would not know where to start with a remark like that. But I will try. It is well known to others that the majority of fatal aircraft accidents are the result of "controlled flight in to terrain". Hence ejection devices would not prevent the majority of fatalities. Instead, the airlines have spent huge amounts of money on EGPWS, (Enhanced Ground Proximity Warning System) and better NAV systems. another worry since 9/11 is bombing. Ejection looses there too, it is two slow. Another scenario is a hijacking by suicidal pilots. Yes, of course just push the button! Well, how are you going to make a pressurized container that can depart the mother ship and remain pressurized? A flat floor won't hold up and taking the wholle fuselage tube weighs a hell of a lot. Next, how are you going to make a parachute that can hold up to deployment at six hundred MPH? Now let's say for your benefit that some of the laws of physics have been repealed and these issues go away. How are you going to deal with the ten two twelve G deceleration? A seat belt? Vermin, those who rely on seat belts are literally strapped in with five tie-downs, two shoulder, two waist and a crotch belt. During ejection, these restraints self tighten, slaming the occupant in to the seat. many have ankle and wrist restraints that pull in as well, they all work in concert. a Martin Baker seat that departs the aircraft is 2-3 million dollars. A seat that remains in the cabin but does all of the above would be at least $750,000. The seats alone would just about double the cost of the 777 which has been around since 1995 and one ain't been lost yet. Doubling the cost with out the other enhancements you envision. What about the occupants who are up and walking around or in the lavatory? They and the flight attendants and the liquor carts and food carts would all become lethal weapons. You can also forget about stowing your bag under your seat.

helo

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#69
In reply to #68

Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 2:07 AM

Helo,

Thanks for that very informed answer! That was great!

Still, isn't there some way when a plane (let's forget helicopters for the moment) is starting it's approach and the pilot knows something is bad (like the one that landed in the ocean off of the Caribbean) could eject his passengers, already strapped in for the landing? No freight, just the passengers. Yes, quite a few might die, but it seems that each time a bad landing is attempted, all die.

I'm assuming during a landing the speed of the plane is more like 200 mph and not 600 mph, so less shock. I am no expert, so I defer to your knowledge.

Again, thanks for that answer!!!

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#70
In reply to #69

Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 2:33 AM

This is an interesting chat (scroll down the bottom for helicopters) - http://forum.keypublishing.co.uk/archive/index.php?t-2252.html

and here is some more stuff (including capsules etc) - http://www.ejectionsite.com/emakers.htm

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#71
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Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 2:35 AM

Well

There was a 757 in the carribean, several years ago that had faulty altitude and airspeed indications because people who cleaned the airplane taped over the static ports. I do not know to what extent the pilots were aware they were getting faulty info. Usually, with a problem on approach, you either go around or it is two late. People die in race cars all the time at 200 mph with five point belts, contoured seats, helmets and neck restraints. None of these are available in your scenario. In addition, low and slow has it's own set of problems. The Martin Baker zero-zero seat has a stabilized rocket that actually propels the seat and occupant up to an altitude where the chute can be safely deployed. Do you really think that one could economically carry a huge rocket around to propel not just an occupant, but the entire cabin, including galleys, meals, lavatories, stow bins, carry on baggage in the stow bins, magazines, safety literature cards, barf bags, carpeting, movie screens and the six cockroaches that live under the galley to a safe altitude? If you are limiting your system to a low and slow scenario, then you have spent a huge amount of money for not much survivability.

helo

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#72
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Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 2:45 AM

Well, I'm not saying that the shape of airliners wouldn't be somewhat different, and accommodations within the cabin would be compromised. But for better safety, I could deal with that.

In the incident I was talking about, I think the plane had been hijacked by a couple of guys that didn't believe the pilot when he said that he didn't have enough fuel to fly them where they wanted to go. As a result, he was forced to ditch the plane in the Caribbean.

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#73
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Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 3:14 AM

That was maybe a 767 in a resort island area in Africa. (Cape Verde Islands perhaps?) If so it was in broad daylight and was the one that was filmed from the beach where it hit slightly left wing down and slewed around to the left away from the camera and the aft fuselage broke off. Well, if that was the one, a lot of pax survived, and many more would have except for language problems in that a lot of people inflated life jackets before they hit the water and floated up to the area between the seats in the inverted aft fuselage. They struggled and drowned when others got out. I would suggest that better multilingual instruction equipment would have helped on that one. Anyway, that scenario has been thwarted by a variety of improvements since 9/11 including a flight deck door that does it's job. (I know, I installed some of them). I think if hi jacking is the problem then these are better solutions than the human cannonball trick.

helo

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#74
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Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 7:56 AM

Vermin,

Aircraft, of all kind are not inherently dangerous. Statistics show that the number of fatalities per traveled mile per time per number of passengers, is by far higher in cars than they are in airplanes. than why not an ejection seat for cars? Did you know that the number of sports related fatalities are higher than all aircraft accidents combined? any suggestions here? maybe a tie down seat? or strait jacket?

We have a saying in the industry, that the most dangerous part of air travel is the way to the airport.

Safety should always be a top consideration, but when logic fail, and limits are not drawn, all the rest fails too.

Wangito.

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#75
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Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 8:13 AM

than why not an ejection seat for cars?

erm... http://www.mi6.co.uk/sections/q-branch/astonmartindb5.php3

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#76
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Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 12:13 PM

The fatality rate in aero vs auto accidents is noteworthy when citing such stats.

cr3

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#77
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Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 1:52 PM

Absolutely,

NTSB 2004 statistics: Ratio between fatal car and aeroplane accidents is:

8.6 to 0.4 for each 1 billion passengers miles per year. that is a staggering difference of over 21 Car fatalities for each aeroplane accident fatality.

The massage is laud and clear.

Wangito.

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#78
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Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 5:19 PM

Getting back to the original post topic:

Let's forget about synchronizing an ejection pod through spinning rotors (bad! idea), attempting to stop a large rotating mass (helo blades) on the order of stopping a lightweight table saw blade (which was, incidentally, a great idea), or, etc.

If we're going to eject a parcel containing human life then we to need:

first: get rid of the spinning obstacle (rotors)!

1) Eject rotor assembly explosively with the provision that:

Rotors will be designed such that they are attached to each other slightly outboard of hub with a high tensile cable. (normally, the cable has no tension and just rides along with the rotors). Within each blade root (where cable is attached) is a winching mechanism that will reel in the blade hubs to each other in a stepped fashion, once the explosive charge is fired (you ME's figure that one out!). The intent of this is to contain the spinning mass into a random mass that with stepped containment, has, potentially, no specific vector; i.e., it drops, as opposed to each rotor being slung outwardl, randomly, in all directions.

The only purpose in this is to (possibly) protect human life on the ground. Ostensibly, if one were to design such a complicated mess as this, it should include some sort of directional guidance mechanism, but OTOH if failure is over a populated area, the rotor landing site would most likely be secondary to fuselage landing site? Anyway, back at the catastrophe design ranch:

2) Milliseconds later, once rotors are no longer a threat, we have multiple options:

a) Fire an ejection pod, containing either:

1) Crew only

2) Crew and passengers (preferred)

3) passengers only

Or:

b) Fire a parachute module that will safely drop helo and contents.

Or:

c) Insist that all catastrophes occur over water and all helos must have suitable seaplane type landing pods (in addition to all of the above).

Or:

d) Have the pilot call the "prayer request line".

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#79
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Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 5:41 PM

How about converting the spinning mass, that once ejected by exploding bolts, and secured by cables/teathers, it starts pulling the engine and back section from the helicopter, then once that assembly is ejected, explosive bolts blow shearing the rest of the now useless part of the craft away.

after that, a chute is ejected by a explosive canister and inflated (much the similar principle to a airbag system, but the bag being in the shape of a parachute...

And to the question of decelerating using parachutes from 600 mph/kmh/whatever you deploy a small drone chute to decrease your speed.

NASA had been doing it for years with the capsules before the shuttle.

How do you get all the occupants from the jet? BLOW the ass off the jet (tail and all) and suck the people out the back with teather/chutes.

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#80
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Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 6:07 PM

"How about converting the spinning mass, that once ejected by exploding bolts, and secured by cables/teathers, it starts pulling the engine and back section from the helicopter"

So now we have this spinning mass! Now what? Forget the chopper. What shall we do with what we've created? I got it! We now have a gyroscope!

Now, how can we use this to salvage the dying craft and crew?

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#85
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Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 11:24 PM

Of course, you could always have the ejection blast just pointed at the passengers... On the other hand, how does all this shake out if you're in an autogyro?

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#87
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Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 11:37 PM
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#81
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Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 8:23 PM

Maybe they could house the crew in an extremely long 'nose-section' of the helicopter. They could thus eject without being near the rotor blades. Passengers would be somewhat stuck, but flight crew cost more to train.

http://josh.samuel.googlepages.com/stupidhelicopter

I think there is a brand of helicopter that can do a full inversion (in the air) , so 'downward' ejection may not be such a bad idea. The above pic is for simple amusements sake - I couldn't find a pic of the bird I meant. (but the pilot in the pic is welcome to come mow my lawn !)

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#82
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Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 8:35 PM

Cute(?) picture Kris.

Somehow, my previous post (that you replied to) got truncated. Can't imagine how it happened unless it somehow had something to do with the numbering and tabs I was doing.

Will try to reconstruct it for later deep consideration.

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#83
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Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 8:36 PM

P.S. refer back to post # 78.

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#84
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Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 8:42 PM

I got really annoyed trying to cut 'n' paste the picture direct, but had no success. Usually this works, but I had to resort to putting a link in. I don't know which is more annoying - a picture loading direct for somebody with a slow computer, or a link to 'who-knows where'.

There, I did it the long way by saving it to HD first then using the editors image insertion button. I've no idea why it didn't work the easy way.

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#86
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Re: Helicopter Ejection Seats - via Main Rotor area

12/19/2007 11:28 PM

helo & wangito,

Both really good info. Thanks!

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#88

Re: Helicopter Ejection Seats - via Main Rotor area

12/20/2007 7:40 PM

Can a parchute be deployed safely from the normal cruising height?

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#89
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Re: Helicopter Ejection Seats - via Main Rotor area

12/20/2007 8:15 PM

Yes! A parachute can be deployed safely from just about any height. Can the safely deployed parachute return its contents safely to earth is another matter.

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#90
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Re: Helicopter Ejection Seats - via Main Rotor area

12/20/2007 8:32 PM

Kevlar pants ? At least the important bits would be safe ! I watched Bear Grylls simply jump from a chopper onto sand dunes yesterday (on TV of course).

The 'jump' option is sounding increasingly attractive.

Getting a bit of rope out might be time consuming. I know, I'm rapellent !

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#93
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Re: Helicopter Ejection Seats - via Main Rotor area

12/20/2007 10:01 PM

Hahahaha!! Good link Kris. The jump link was most entertaining.

As we concluded reading the link we discovered the obvious:

"Failure is not an option." (Ed Harris, as the guy in Apollo 13 who says, "Failure is not an option")

Waking up at ~15k', it would be quite an accomplishment to reach out and grab that (just happened to be floating by) parachute. Miracles have happened though. Do you recall the case of the girl that actually fell from a plane at some gowdawful height (multiple K') and landed in a snowbank and survived. Don't have a link but it is a true story. Wonder if she was inventorying what was available on the way down?

I heard the inside scoop on Bear Grylls. Off camera, he stays in hotel rooms, indulges in amenities that the camera won't show you. However, it's still an entertaining program.

-John

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#95
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Re: Helicopter Ejection Seats - via Main Rotor area

12/20/2007 10:55 PM

I think this is the gal who survived a rather bad fall. Couldn't find a better link, but it's still interesting. ( They build girls tough in Eastern Europe ! )

yeah, I read the stuff on Bear as well. Not really surprising (true or not), but he does have an awesome 'go for it' spirit, especially when you read about how he survived a nasty parachute accident. I'd like to stick him and Ray Mears on a desert Island and see who survived best. Ray get's my vote for nice guy (never trust the quiet modest ones I say). It would be good 'reality' TV, and could be formatted a bit like that Lee Marvin film "Hell in the Pacific". My version would be "Hell on the Isle of Wight" (Rockall would be too confined, and the IOM might get annoyed cos of disappearing bikers)

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#97
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Re: Helicopter Ejection Seats - via Main Rotor area

12/21/2007 12:33 AM

I'm guessing that if the accident involved losing your tail rotor, the spin of the helicopter would make it all but impossible to get out of the craft.

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#98
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Re: Helicopter Ejection Seats - via Main Rotor area

12/21/2007 12:48 AM

Well you could jump out, but you'd spin an awful lot ! Just got my son one of those R/C helicopters (actually it's IR) and I still cant fly the thing. Can't even figure out the mechanics of it. Somewhere there is a good thread on these toys. Mega-good fun to play with. If I ever get the skill, I'm going to see if I can strap an Action Man to one ( don't think it has enough thrust though)

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#91
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Re: Helicopter Ejection Seats - via Main Rotor area

12/20/2007 8:38 PM

Then, give an answer for the second part of your statement!

The question addresses the deployment and the delivery of the PARCEL!

OBVIOUSLY!

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