Seatbelts & broken necks.

[birdy]

Are shoulder straps on gyro harnesses needed?
Are they dangerous?
The reason i ask is coz, wen your go'n in, [ speakn from multiple experiances here] you instinctivly brace yourself moments before impact.
We know that be'n straped to the machine till it stops flyn to pices and bouncing is much safer than be'n spat out, but of all the bingles iv had, iv never gotn hurt [ yet], and i havent worn anythn but a lap strap.
If we come to a sudden stop, we lurch forward till the belts take hold. Well, most of us dose. Our head, inside the skid lid, is not restrained at all. The average adult scon is 7kg, plus helmet. Its easy to consieve the neck be'n under real stress tryn to hold back your head, and even easier to imagine it be'n snaped from such a violent bending moment.
If, OTOH, we only had a lap strap on, we'd bend at the waist, absorbn some of the deceleration, till we were horisontal. Then our head stops, but our neck is now in line with the deceleration force, so its not go'n to be wiped.
Bendn at the waist will probably have you head buttn sumthn , but id rather a rearranged face than a broken neck.

An option would be to have a full harness AND a restraining line to the brain bucket, so your head dont wip forward.

Wot say you mob?

 

[Gyro_Kai]

Hi Birdy,

I really think a 4 point restraint is necessary and additionally some kind of head "rest" i.e. something stopping the head on backward movement e.g. the mast.

They have made a lot of experiments in the car industry and of course the same arguments came.

Taking only forward motion into consideration now...
A lap-strap has the following disadvantages:

• The entire deceleration force is held back by a very small strip positioned in a soft area of the body, thereby possibly causing internal damage. Spreading the load over a bigger surface, some being the ribcage and shoulders is better.
• The forward swinging upper body will possibly find something on it's way (cockpit, stick) and cause severe damage to face, head or chest.

The 3 or 4 point belt has one disadvantage:

• The whip-lash effect of the body being thrown backwards after the belt worked and the head tilting over the back-rest. Cars with belts but without head-rest at adequate height can be real killers

.

The forward lash is apparantly not a problem in cars, but there you don't wear a helmet, so that is yet to be researched.

If the impact is not in the flying direction it is particularly good to have your upper body restrained as well. This may seem a strange concept, but we had a case here with the back seat cushion going through the prop which broke and hit the rudder. The pilot survived, but his landing roll was sideways. Also if you land in the tree canopy, you may have a second landing on the ground in any possible direction.

Oh, one final remark about bracing oneself. Seatbelt-avoiders always use that as a reason not to buckle up. When impact is above 60km/h the forces involved are often measured in metric tons. If you can "handle" that, fine..

Kai.

 

[birdy]

The entire deceleration force is held back by a very small strip positioned in a soft area of the body, thereby possibly causing internal damage.
Id rather have a squashed spleen than a broken neck.

If the impact is not in the flying direction it is particularly good to have your upper body restrained as well.
Thats a point iv thought of, but usualy gyro crashes are not of high horisontal speeds, so not as bad.

Oh, one final remark about bracing oneself. Seatbelt-avoiders always use that as a reason not to buckle up.
I never said i didnt ware one.

 

[Gyro_Kai]

The entire deceleration force is held back by a very small strip positioned in a soft area of the body, thereby possibly causing internal damage.
Id rather have a squashed spleen than a broken neck.

Yes, I understand, but apparantly the "nod" is not as bad a the back-lash afterwards.

If the impact is not in the flying direction it is particularly good to have your upper body restrained as well.
Thats a point iv thought of, but usualy gyro crashes are not of high horisontal speeds, so not as bad.

Yes, agreed.

Oh, one final remark about bracing oneself. Seatbelt-avoiders always use that as a reason not to buckle up.
I never said i didnt ware one.

I didn't suggest that, I'm only quoting research done for cars and there they had to counter the argument, of "I can hold on myself".

Again, what it means to do an involuntary "nod" with helmet, I cannot say anything, but for all other cases it seems to be better to have a 4-point restraint.

Kai.

 

[brett s]

I've seen the end results of enough helicopter crashes (including a few where pilots weren't wearing available shoulder harnesses) to say there's no way I'm flying without shoulder straps. In some crashes it might not make a difference, in some it will!

It's not pretty when your face hits the panel or stick...

 

[Vance]

In my streamlined motorcycle when the parachute didn’t open at 265 miles per hour the low estimate on altitude was 20 feet and the high estimate was 35 feet. The touch downs were 300 feet apart in the beginning as it tumbled end over end like a football and it lasted for ¾ of a mile. I had a five point restraint and arm restraints as well as a simple pad under the helmet for a neck brace. My only injury was my head injury so apparently the neck does not break quite as easily as one might imagine. It is hard for me to visualize just how this would all work together in a gyroplane accident. My head injury was a from my head snapping back into the roll cage rear cap when the streamliner landed hard on its wheels after landing hard on it’s nose. We had not imagined the amount of forward head movement that I had. The restraint system was designed over several days by Jim Deist. To this day I thank him every time I see him for saving my life.

You are sitting more upright in a gyroplane so that could make it harder on the neck.

A heavy helmet definitely makes it harder on the neck and perhaps easier on the head.

It is my understanding that it is best to have the body decelerate with the rest of the vehicle in order to avoid secondary impacts.

Something I have seen in some gyroplanes is shoulder belts that fasten to the frame below the shoulders. This has a tendency to break your back in a severe forward impact. It is hard to imagine an impact where being held down is important in a gyroplane accident. I suspect that this design may come from fixed wing negative g events.

There is also the question of the upper rear mounts for the shoulder restraints causing injury with the typical mast deformation that takes place when the rotor slows prematurely.

I feel it is good to consider these things plus the danger of fire. It is hard to imagine the different ways to dissipate stored kinetic energy over the time available without producing life threatening injuries. I feel it is time well spent.

Thank you, Vance

 

[automan1223]

Acceleration and deceleration factors

Acceleration and deceleration factors

Gyros, Usually are not going 200 mph when they go in. So to compare restraint needs from cars and motorcycles to gyros is not quite accurate or fair.

If anyone here has watched those medical emergency shows on discovery channel, many times there are horrible internal tears and injuries from being belted in too well. Your critical squishy organs like your brain, HEART and your LUNGS are fed with arteries that can tear loose if the decel is too great. You will bleed to death internally before they figure out where all your blood is going.

Seeing Larry Neals landing gear "drop in" is a perfect example for controlled deceleration. Your internal organs will have no "suspension" if you are belted and strapped in every which way.

Saying that I guess it depends how stout your airframe is and what kind of wreck you plan to be in. I am not 100 % sold on shoulder harness.

We are not driving race cars or salt flats.

Jonatghan

 

[Jim]

Birdy,

Last year I was involved in an ultralight accident. I wore a 4 point harness and a full face helmet. The impact was so severe that my helmet was ripped off my head. It had deep gashes where it hit the tubes. I broke my pelvis, four ribs, and my tail bone on several places. The airplane was totally destroyed.

Believe me, the impact is so severe and so fast that you know nothing while it is happening. I am very glad for the four point harness and helmet. I received no injuries to my neck, not even a sore one afterwards.

To make a long story short, I will always wear a helmet and a four point harness if I have the choice.

Jim

 

[Gyro_Kai]

If anyone here has watched those medical emergency shows on discovery channel, many times there are horrible internal tears and injuries from being belted in too well. Your critical squishy organs like your brain, HEART and your LUNGS are fed with arteries that can tear loose if the decel is too great. You will bleed to death internally before they figure out where all your blood is going.

Hello,

I have some doubts on "belted in too well" when it comes to cars or other vehicles below 200 mph. if the crash was so severe, that a correctly positioned belt tears up your internals, what is the alternative?
Not belt up and ooze into the cockpit or next obstacle after hard impact?
Belts should be dimensioned to give way a little, every fraction of an inch means heaps of g-reduction. Cockpits usually aren't.

Obviously an airbag ADDITIONALLY can increase survivability, but if deceleration is as bad as tearing of organs, you are on the way to a better world already.

Kai.

 

[Racer]

Here are some things to help keep you from being a "Bobble Head"

 

[Mayfield]

David,

Have you read about the HANS Device? I'm not certain that it would provide enhanced protection in our typical crash scenario, but it is interesting.

https://en.wikipedia.org/wiki/HANS_device

Jim

 

[Vance]

In my opinion it is about g force over time. Anything you can do to reduce the force or extend the time helps survivability.

The primary difference between the race bike and a gyroplane is the structure. In my opinion the deceleration over time is not that different than many aircraft unintended impacts with terrain.

In a lightly built aircraft there is the supplementary challenge of the deformation of the structure in a life threatening way. I would not want to be attached to some component that is going to depart from some other component that I am also attached to.

In a rotor craft there is the further challenge of managing the stored energy in the rotor.

Thank you, Vance

 

[hjajr]

I just felt safer using a lap belt due to the fact that I might miss a rotor blade when being in the up right position in a crash using the 4 point harness.

 

[fiveboy]

G Force & Survival

G Force & Survival

I did a show two years ago for Nat Geo International called ESCAPING DEATH. In it we looked at all the newest technology to make a deadly situation survivable (hi rise fires, stampeding crowds, etc). One of the things focused on were seats being developed for commercial airlines where the G forces forward were incrementally absorbed by essentially pneumatic pistons on the seat bottoms where the bulk of the forward force wanted to rip the seat and its occupant out and into the nose of the cabin.

Surely something like this would be a great enhancement on our gyros. The issue becomes space and weight.... and cost.

Some variation on Larry Neals Butterfly suspension facing forward and miniaturized might be just the ticket?

 

[fiveboy]

One Other Thought

One Other Thought

... also in that show was an impact activated suit for motorcycle riders that essentially was a big airbag that enveloped them. Why couldn`t we just have airbags that deploy based on a robust impact sensor?

Seats that provide a neck support for whiplash would also be useful.

 

[mgoroff]

There's a good discussion of the technology to be found in auto racing harnesses at Schroth Racing. The most common cause of fatalities in racing crashes used to be neck injuries but most sanctioning bodies now require a head restraint, such as HANS. There a good discussion and some interesting crash test video here.

In my SparrowHawk, I consider a shoulder harness to be required to avoid impact with the enclosed cabin in a sudden stoppage. In my track car, I wear a 6 pt harness attached to the frame and a 1.75" DOM steel harness bar, and am fastened into a racing seat. The belt system in my gyro isn't anywhere close to the system in the car, but I think any impact in the gyro is likely to be at a much slower speed than the car with much smaller g-forces. OTOH, the HGU-56 helmet I wear in the gyro is much lighter and probably more effective than my racing helmet, but it doesn't have the required SFI certifications for track use. I'm not nearly as concerned with neck injuries in the gyro due to the speeds involved. I'm more worried about sitting on top of a fuel tank that can easily rupture.:flame:

Marc

 

[birdy]

Yes, I understand, but apparantly the "nod" is not as bad a the back-lash afterwards.
Theres no backlash, if you spine and neck are in line.
You only get it if theres a recoil, like wen you bend.

It's not pretty when your face hits the panel or stick...
Its not pretty see'n one of your best mates ina bed, known he'll probably never walk again either.

In my streamlined motorcycle when the parachute didn’t open at 265 miles......
Cant say iv ever heard a gyro do'n that speed Vance.

You are sitting more upright in a gyroplane so that could make it harder on the neck.
Most gyro seats iv seen have the back leaning back abit, so yeh, its much worse.

It is hard to imagine an impact where being held down is important in a gyroplane accident.
I ware it for the neg Gs Vance.

Last year I was involved in an ultralight accident.
Glad to hear you still with us Jim, but we are talkn apples, not oranges.

In a rotor craft there is the further challenge of managing the stored energy in the rotor.
The ground generaly takes care of that pretty well Vance.

I'm not nearly as concerned with neck injuries in the gyro due to the speeds involved.
With respect Marc, my mate was ina R22, and it just fell over, slowly, and he's not likely to walk again.
It dont take much to snap it.

 

[Resasi]

Birdy the forces in any crash would have to be complex and multidirectional. One probably tendssimply to think of a massive deceleration with the upper body in a lap harness being flung forward as you described, with the head more or less in line with the upper torso. A 4 point restraining the upper torso and the head going forward at 90 degrees to it unless it too was restrained with the HANS.

I would have thought of a gyro crash as having a forward deceleration then complicated by the rotational element of the blades. A sort of twisting forward tumble and roll with the head being whipped around. In this case a 4 point may hold the upper torso preventing it from flailing around quite so much as a simple lap restraint.

Never having been witness to a gyro self destructing other than one on youtube I was trying to imagine it. That Ken Wallis downwind engine out was what I think it might be like. He luckily emerging from that unscathed and waving to the crowd thank goodness. What sort of harness was he wearing?

 

[Hognose]

Some deceleration forces are unsurvivable. It depends on the axis of the force, and as Vance intuits, the amount of deceleration delivered over time. A sharp spike that just lasts a millisecond is less serious than a much lower force delivered over a second and a half.

One problem is the vertical axis. The body is rather weak in receiving this kind of impact. the spine can break out the bottom of the skull and intrude into the braincase, an unsurvivable injury.

On the plus side, I think Birdy's friend has a chance to walk again within our own lives. Some new research out on restoring severed nerves electronically, in great apes, is only one of many promising lines of research.

It's an ill wind that blows no good at all, and one of the interesting things coming from the war is lots of funding for high-tech treatment research, which is already showing some results.

In the Wallis crash, it looked like (1) he hit with both a vertical and a forward velocity, and (2) he hit on a relatively soft turf field. Still it's blind luck that he survived.

Crashworthiness means:

• Not being ejected from the aircraft
• Not having the aircraft structure or outside objects intrude into the space occupied by your living organism;
• absorbing (physcially) and stretching out (in time) deceleration forces;
• not striking any protuberant object in the aircraft;
• not having fire break out;
• making a safe and speedy exit from the wreckage once it has come to rest.

Rather a lot of variables to keep in mind, and that's not a comprehensive list.

cheers

-=K=-

 

[GyroRon]

I am happy with my lap belt.